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217000.9945Drug resistance in bacteria isolated from patients presenting with wounds at a non-profit Surgical Center in Phnom Penh, Cambodia from 2011-2013. BACKGROUND: Emerging antibiotic resistance amongst clinically significant bacteria is a public health issue of increasing significance worldwide, but it is relatively uncharacterized in Cambodia. In this study we performed standard bacterial cultures on samples from wounds at a Non-Governmental-Organization (NGO) Hospital in Phnom Penh, Cambodia. Testing was performed to elucidate pathogenic bacteria causing wound infections and the antibiotic resistance profiles of bacterial isolates. All testing was performed at the Naval Medical Research Unit, No.2 (NAMRU-2) main laboratory in Phnom Penh, Cambodia. METHODS: Between 2011-2013, a total of 251 specimens were collected from patients at the NGO hospital and analyzed for bacterial infection by standard bacterial cultures techniques. Specimens were all from wounds and anonymous. No specific clinical information accompanied the submitted specimens. Antibiotic susceptibility testing, and phenotypic testing for extended-spectrum beta-lactamase (ESBL) were performed and reported based on CLSI guidelines. Further genetic testing for CTX-M, TEM and SHV ESBLs was accomplished using PCR. RESULTS: One-hundred and seventy-six specimens were positive following bacterial culture (70 %). Staphlycoccus aureus was the most frequently isolated bacteria. Antibiotic drug resistance testing revealed that 52.5 % of Staphlycoccus aureus isolates were oxacillin resistant. For Escherichia coli isolates, 63.9 % were ciprofloxacin and levofloxacin resistant and 96 % were ESBL producers. Resistance to meropenem and imipenem was observed in one of three Acinetobacter spp isolates. CONCLUSIONS: This study is the first of its kind detailing the antibiotic resistance profiles of pathogenic bacteria causing wound infections at a single surgical hospital in Cambodia. The reported findings of this study demonstrate significant antibiotic resistance in bacteria from injured patients and should serve to guide treatment modalities in Cambodia.201528883936
226910.9943Genomic detection of Panton-Valentine Leucocidins encoding genes, virulence factors and distribution of antiseptic resistance determinants among Methicillin-resistant S. aureus isolates from patients attending regional referral hospitals in Tanzania. BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a formidable public scourge causing worldwide mild to severe life-threatening infections. The ability of this strain to swiftly spread, evolve, and acquire resistance genes and virulence factors such as pvl genes has further rendered this strain difficult to treat. Of concern, is a recently recognized ability to resist antiseptic/disinfectant agents used as an essential part of treatment and infection control practices. This study aimed at detecting the presence of pvl genes and determining the distribution of antiseptic resistance genes in Methicillin-resistant Staphylococcus aureus isolates through whole genome sequencing technology. MATERIALS AND METHODS: A descriptive cross-sectional study was conducted across six regional referral hospitals-Dodoma, Songea, Kitete-Kigoma, Morogoro, and Tabora on the mainland, and Mnazi Mmoja from Zanzibar islands counterparts using the archived isolates of Staphylococcus aureus bacteria. The isolates were collected from Inpatients and Outpatients who attended these hospitals from January 2020 to Dec 2021. Bacterial analysis was carried out using classical microbiological techniques and whole genome sequencing (WGS) using the Illumina Nextseq 550 sequencer platform. Several bioinformatic tools were used, KmerFinder 3.2 was used for species identification, MLST 2.0 tool was used for Multilocus Sequence Typing and SCCmecFinder 1.2 was used for SCCmec typing. Virulence genes were detected using virulenceFinder 2.0, while resistance genes were detected by ResFinder 4.1, and phylogenetic relatedness was determined by CSI Phylogeny 1.4 tools. RESULTS: Out of the 80 MRSA isolates analyzed, 11 (14%) were found to harbor LukS-PV and LukF-PV, pvl-encoding genes in their genome; therefore pvl-positive MRSA. The majority (82%) of the MRSA isolates bearing pvl genes were also found to exhibit the antiseptic/disinfectant genes in their genome. Moreover, all (80) sequenced MRSA isolates were found to harbor SCCmec type IV subtype 2B&5. The isolates exhibited 4 different sequence types, ST8, ST88, ST789 and ST121. Notably, the predominant sequence type among the isolates was ST8 72 (90%). CONCLUSION: The notably high rate of antiseptic resistance particularly in the Methicillin-resistant S. aureus strains poses a significant challenge to infection control measures. The fact that some of these virulent strains harbor the LukS-PV and LukF-PV, the pvl encoding genes, highlight the importance of developing effective interventions to combat the spreading of these pathogenic bacterial strains. Certainly, strengthening antimicrobial resistance surveillance and stewardship will ultimately reduce the selection pressure, improve the patient's treatment outcome and public health in Tanzania.202539833938
218220.9942Antibiotic resistance and virulence profiles of Proteus mirabilis isolated from broiler chickens at abattoir in South Africa. BACKGROUND: Proteus mirabilis has been identified as an important zoonotic pathogen, causing several illnesses such as diarrhoea, keratitis and urinary tract infections. OBJECTIVE: This study assessed the prevalence of P. mirabilis in broiler chickens, its antibiotic resistance (AR) patterns, ESBL-producing P. mirabilis and the presence of virulence genes. METHODS: A total of 26 isolates were confirmed as P. mirabilis from 480 pooled broiler chicken faecal samples by polymerase chain reaction (PCR). The disk diffusion method was used to evaluate the antibacterial susceptibility test, while nine virulence genes and 26 AR genes were also screened by PCR. RESULTS: All 26 P. mirabilis isolates harboured the ireA (siderophore receptors), ptA, and zapA (proteases), ucaA, pmfA, atfA, and mrpA (fimbriae), hlyA and hpmA (haemolysins) virulence genes. The P. mirabilis isolates were resistant to ciprofloxacin (62%) and levofloxacin (54%), while 8 (30.7%) of the isolates were classified as multidrug resistant (MDR). PCR analysis identified the bla(CTX-M) gene (62%), bla(TEM) (58%) and bla(CTX-M-2) (38%). Further screening for AMR genes identified mcr-1, cat1, cat2, qnrA, qnrD and mecA, 12%, 19%, 12%, 54%, 27% and 8%, respectively for P. mirabilis isolates. The prevalence of the integron integrase intI1 and intI2 genes was 43% and 4%, respectively. CONCLUSIONS: The rise of ciprofloxacin and levofloxacin resistance, as well as MDR strains, is a public health threat that points to a challenge in the treatment of infections caused by these zoonotic bacteria. Furthermore, because ESBL-producing P. mirabilis has the potential to spread to humans, the presence of bla(CTX) (-M) -producing P. mirabilis in broilers should be kept under control. This is the first study undertaken to isolate P. mirabilis from chicken faecal samples and investigate its antibiotic resistance status as well as virulence profiles in South Africa.202438357843
211630.9942Antibiotic Resistance Genes Among Carbapenem-resistant Enterobacterales (CRE) Isolates of Prapokklao Hospital, Chanthaburi Province, Thailand. BACKGROUND: The global spread of carbapenem-resistant Enterobacterales (CRE) inflicts a severe threat to human health. The CRE infections have resulted in an increased mortality rate in hospitals and other health-care settings worldwide. In this study, the antibiotic-resistance pattern and prevalence of carbapenemase-encoding genes among CRE isolated from patients of one hospital in Thailand were investigated. METHODS: By using conventional biochemical tests, we identified and isolated all species of Enterobacterales from the clinical samples kept at Prapokklao Hospital, Chanthaburi, Thailand, which were collected during 2016-2017. Multidrug-resistant (MDR) bacteria were determined by disc diffusion method and minimum inhibitory concentration (MIC) test strips. Carbapenemase genes were detected by PCR and confirmed by Sanger sequencing. RESULTS: Klebsiella pneumoniae complex, Escherichia coli, and Enterobacter spp. were isolated from the specimens. Of 9,564 isolated Enterobacterales, 282 were multidrug-resistance (MDR). The MIC test strips revealed that the MDR CRE were resistant to ertapenem (92.9%) and meropenem (81.3%). All these isolates carried carbapenemase-coding genes, including bla (NDM) (90%) and bla (IMP) (71%), the two most commonly found genes among CRE strains. There were 39.2% of the isolates that carried a combination of bla (NDM)-bla (IMP) and 22.6% carried combined bla (NDM)-bla (IMP)-bla (OXA-48-like) genes. CONCLUSION: This study demonstrates a significantly high prevalence of CRE isolates with the MDR phenotypes. A minority of the isolates carried a single carbapenem-resistant gene, while the majority harbored multiple genes in combination. Regular monitoring of MDR CRE and characterization of their drug resistance are important for guiding treatment, intervention and control of the CRE spread and outbreak in a health-care setting.202134511940
230040.9942Determining the Disinfectants Resistance Genes and the Susceptibility to Common Disinfectants of Extensively Drug-Resistant Carbapenem-Resistant Klebsiella pneumoniae Strains at a Tertiary Hospital in China. Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection has become a significant threat to global health. The application of chemical disinfectants is an effective infection control strategy to prevent the spread of CRKP in hospital environments. However, bacteria have shown reduced sensitivity to clinical disinfectants in recent years. Furthermore, bacteria can acquire antibiotic resistance due to the induction of disinfectants, posing a considerable challenge to hospital infection prevention and control. This study collected 68 CRKP strains from the Fifth Affiliated Hospital of Xinjiang Medical University in China from 2023 to 2024. These strains were isolated from the sputum, urine, and whole blood samples of patients diagnosed with CRKP infection. Antibiotic susceptibility tests were performed on CRKP strains. Concurrently, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of disinfectants (benzalkonium bromide, 1% iodophor disinfectant, alcohol, and chlorine-containing disinfectant) against the test isolates were determined by the broth microdilution method. The efflux pump genes (cepA, qacE, qacEΔ1, qacEΔ1-SUL1, oqxA, and oqxB) were detected using polymerase chain reaction. The results showed that 21 out of the 68 CRKP strains exhibited extensive drug resistance, whereas 47 were nonextensively drug-resistant. The MIC value for benzalkonium bromide disinfectants displayed statistically significant differences (p < 0.05) between extensively drug-resistant (XDR) and non-XDR strains. Additionally, the MBC values for benzalkonium bromide disinfectants and 1% iodophor disinfectants displayed statistically significant differences (p < 0.05) between XDR and non-XDR strains. The detection rates for the efflux pump genes were as follows: cepA 52.9%, qacE 39.7%, qacEΔ1 35.2%, qacEΔ1-SUL1 52.9%, oqxA 30.8%, and oqxB 32.3%. The detection rate of the qacEΔ1-SUL1 gene in XDR CRKP strains was significantly higher than in non-XDR CRKP strains (p < 0.05). This indicates a potential link between CRKP bacterial disinfectant efflux pump genes and CRKP bacterial resistance patterns. Ongoing monitoring of the declining sensitivity of XDR strains against disinfectants is essential for the effective control and prevention of superbug.202439166283
89850.9942Characterisation of mobile colistin resistance genes (mcr-3 and mcr-5) in river and storm water in regions of the Western Cape of South Africa. BACKGROUND: Colistin is regarded as a last-resort antimicrobial against multi-drug resistant Gram-negative bacteria (GNB), therefore the dissemination of colistin resistance in the environment is of great concern. Horizontal transfer of mobile colistin resistance (mcr) genes to potential pathogens poses a serious problem. This study aimed to describe the presence of colistin resistant GNB and mcr genes in river and storm water in regions of the Western Cape. METHODS: Water samples were collected from three rivers during May 2019 and January 2020 and two storm water samples were collected in November 2019. Colistin resistant GNB were cultured on MacConkey agar containing colistin and identified by MALDI-TOF. Colistin resistance was confirmed using broth microdilution (BMD). mcr-1-5 genes were detected by PCR performed directly on the water samples and on the colistin resistant isolates. mcr functionality was assessed by BMD after cloning the mcr genes into pET-48b(+) and expression in SHuffle T7 E. coli. RESULTS: mcr-5.1 and various mcr-3 gene variants were detected in the Plankenburg-, Eerste- and Berg rivers and in storm water from Muizenberg, and only mcr-5.1 was detected in storm water from Fish Hoek. Colistin resistant GNB were isolated from all of the water sources. Aeromonas spp. were the most common colistin resistant organisms detected in the water sources; 25% (6/24) of colistin resistant Aeromonas spp. isolated from the Berg river contained novel mcr-3 variants; mcr-3.33 (n = 1), mcr-3.34 (n = 1) mcr-3.35 (n = 1) mcr-3.36 (n = 2) and mcr-3.37 (n = 1), which were confirmed to confer colistin resistance. CONCLUSIONS: The mcr-5.1 and mcr-3 colistin resistance gene variants were present in widely dispersed water sources in regions of the Western Cape. The mcr genes were only detected in water sampled downstream of and alongside communities, suggesting that their presence is driven by human influence/contamination. This is the first documentation of mcr-3 and mcr-5 gene variants in any setting in South Africa. Spill-over of these genes to communities could result in horizontal gene transfer to pathogenic bacteria, exacerbating the challenge of controlling multidrug resistant GNB infections.202134187559
84860.9940Molecular Characterization of Escherichia coli Causing Urinary Tract Infections Through Next-Generation Sequencing: A Comprehensive Analysis of Serotypes, Sequence Types, and Antimicrobial and Virulence Genes. Introduction An enormous increase in antimicrobial resistance (AMR) among bacteria isolated from human clinical specimens contributed to treatment failures. Increased surveillance through next-generation sequencing (NGS) or whole genome sequencing (WGS) could facilitate the study of the epidemiology of drug-resistant bacterial strains, resistance genes, and other virulence determinants they are potentially carrying. Methods This study included 30 Escherichia coli (E. coli) isolates obtained from patients suffering from urinary tract infections (UTIs) attending Prathima Institute of Medical Sciences, Karimnagar, India. All bacterial isolates were identified, and antimicrobial susceptibility patterns were determined through conventional microbiological techniques and confirmed by automated systems. All the isolates were investigated using NGS to identify genes coding for resistance, such as extended-spectrum beta-lactamases (ESBLs), metallo-beta-lactamases, and virulence genes. Multilocus sequence typing (MLST) was used to understand the prevalent strain types, and serotyping was carried out to evaluate the type of O (cell wall antigen) and H (flagellar antigen) serotypes carried by the isolates. Results The conventional antimicrobial susceptibility testing revealed that 15 (50%) isolates were resistant to imipenem (IPM), 10 (33.33%) were resistant to amikacin (AK), 13 (43.33%) were resistant to piperacillin-tazobactam (PTZ), 17 (56.66%) were resistant to cephalosporins, and 14 (46.66%) were resistant to nitrofurantoin (NIT). Among the isolates, 26 (86.66%) had revealed the presence of multiple antibiotic-resistant genes with evidence of at least one gene coding for beta-lactamase resistance. There was a high prevalence of bla(CTX-M )(19/30, 63.33%) genes, followed by bla(TEM) and bla(OXA-1). The bla(NDM-5) gene was found in three isolates (3/30, 10%). The virulence genes identified in the present study were iutA, sat, iss, and papC, among others. The E. coli serotype found predominantly belonged to O25:H4 (5, 16.66%), followed by O102:H6 (4, 13.33%). A total of 16 MLST variants were identified among the examined samples. Of the MLST-based sequence types (STs) identified, ST-131 (7, 23.33%) was the predominant one, followed by ST-167 (3, 10%) and ST-12 (3, 10%). Conclusions The study results demonstrated that the E. coli strains isolated from patients suffering from UTIs potentially carried antimicrobial resistance and virulence genes and belonged to different strain types based on MLST. Careful evaluation of bacterial strains using molecular analyses such as NGS could facilitate an improved understanding of bacterial antibiotic resistance and its virulence potential. This could enable physicians to choose appropriate antimicrobial agents and contribute to better patient management, thereby preventing the emergence and spread of drug-resistant bacteria.202438576671
135470.9940The prevalence, antibiotic resistance and multilocus sequence typing of colistin-resistant bacteria isolated from Penaeus vannamei farms in earthen ponds and HDPE film-lined ponds in China. The aquaculture environment, especially the culture ponds and aquaculture products, is considered to be an important reservoir of colistin resistance genes. However, systematic investigations of colistin resistance in Penaeus vannamei farming in different culture modes are scarce. In this study, a total of 93 non-duplicated samples were collected from P. vannamei farms in five cities in China from 2019 to 2021. The prevalence, antibiotic resistance and multilocus sequence typing (MLST) of colistin-resistant bacteria were measured and analysed. The results showed that among the 1601 isolates in P. vannamei and its environmental samples, the pollution of colistin-resistant bacteria was serious (the overall prevalence was 37.3% and 28.8%, respectively), regardless of the earthen pond or high-density polyethylene (HDPE) film-lined pond. Among 533 isolates, the prevalence of mobile colistin resistance (mcr) genes, mcr-1, was the highest (60%, 320/533), followed by mcr-4 (1.5%, 8/533), mcr-8 (0.9%, 5/533), mcr-10 (0.6%, 3/533) and mcr-7 (0.4%, 2/533). The prevalence of mcr-1 in earthen ponds was significantly higher than that in HDPE film-lined ponds (67.5% vs. 49.1%, p < .001). The dominant strain carrying mcr-1 was Bacillus spp. (54.1%, 173/320), followed by Enterobacter spp. (8.1%, 26/320), Staphylococcus spp. (6.3%, 20/320) and Aeromonas spp. (5.3%, 17/320). The antibiotic resistance profiles of 173 Bacillus spp. varied among different sampling locations and culture types. These isolates were highly resistant to cefepime, ceftriaxone, trimethoprim-sulfamethoxazole and ceftiofur (>45%), and multidrug-resistant isolates were common (62.4%, 108/173). Sequence type (ST) 26 (37/66, 56%) was found to be the most prevalent ST in mcr-1-positive Bacillus cereus isolated from the aquaculture environment. In summary, our study pointed out that it is necessary to continuously monitor antibiotic usage and its residues regardless of the pond types, especially with regard to critical drugs such as colistin.202235841601
272380.9940Hospital air: A potential route for transmission of infections caused by β-lactam-resistant bacteria. BACKGROUND: The emergence of bacterial resistance to β-lactam antibiotics seriously challenges the treatment of various nosocomial infections. This study was designed to investigate the presence of β-lactam-resistant bacteria (BLRB) in hospital air. METHODS: A total of 64 air samples were collected in 4 hospital wards. Detection of airborne bacteria was carried out using culture plates with and without β-lactams. BLRB isolates were screened for the presence of 5 common β-lactamase-encoding genes. Sequence analysis of predominant BLRB was also performed. RESULTS: The prevalence of BLRB ranged between 3% and 34%. Oxacillin-resistant bacteria had the highest prevalence, followed by ceftazidime- and cefazolin-resistant bacteria. The frequency of β-lactamase-encoding genes in isolated BLRB ranged between 0% and 47%, with the highest and lowest detection for OXA-23 and CTX-m-32, respectively. MecA had a relatively high frequency in surgery wards and operating theaters, whereas the frequency of blaTEM was higher in intensive care units and internal medicine wards. OXA-51 was detected in 4 wards. Acinetobacter spp, Acinetobacter baumannii, and Staphylococcus spp were the most predominant BLRB. CONCLUSIONS: The results revealed that hospital air is a potential route of transmission of BLRB, such as Acinetobacter and Staphylococcus, 2 important causative agents of nosocomial infections. Therefore, improvement of control measures against the spreading of airborne bacteria in hospital environments is warranted.201627021512
94990.9940Molecular and clinical insights into extended-spectrum β-lactamase genes of Klebsiella pneumoniae isolated from neonatal sepsis in Ethiopia. BACKGROUND: Klebsiella bacterial strains harboring Extended-Spectrum Beta-Lactamase (ESBL) enzymes are the primary culprits behind neonatal sepsis globally. These strains significantly impact clinical outcomes due to their multi-drug resistance patterns in local healthcare settings. In response to this spiraling threat, we studied the prevalence and clinical implications of ESBL-encoding genes in neonates hospitalized with confirmed sepsis. METHODS: A correlational study was conducted on 51 neonates diagnosed with sepsis caused by ESBL-positive Klebsiella pneumoniae at Jimma Medical Center spanning from May 2022 to July 2023. Antimicrobial resistance profiles of the bacterial isolates were determined using the Kirby-Bauer diffusion test, while multiplex polymerase chain reaction (mPCR) techniques were employed to identify resistance genes. The correlation between resistance genes and treatment outcomes was analyzed using the phi coefficient (φ) with a significance level below 0.05. The data management was executed through the utilization of WHONET and STATA software platforms. RESULTS: The sample consisted of 26 (50.9%) male and the remaining 25 (49.1%) female neonates, with diverse clinical characteristics. All 51 Klebsiella pneumoniae isolates were 100% resistant to trimethoprim/sulfamethoxazole and ceftriaxone, but showed varying resistance profiles ranging from 30.8% to meropenem to 94.2% to ceftazidime. Notably, all isolates demonstrated multidrug resistance, with 23% of cases showing resistance to seven different antimicrobial classes. The most prevalent resistance genes identified were bla(CTX-M) (96.1%), bla(TEM) (94.1%), and bla(SHV) (88.2%). The majority of isolates (94.1%) carried at least two resistance genes, such as bla(TEM) and bla(CTX) (94.1%), bla(TEM) and bla(SHV) (86.2%), and bla(CTX) and bla(SHV) (86.2%). Notably, 84.3% of the bacteria harbored the trio of bla(TEM), bla(CTX), and bla(SHV) resistance genes, and only the presence of bla(SHV) in monogenic (φ = 0.4, P = 0.01) or the trio of bla(TEM), bla(CTX), and bla(SHV) genes (φ = 0.3, P = 0.02) showed positive correlation with neonatal mortality. CONCLUSION: We observed a significant prevalence of multidrug-resistant Klebsiella pneumoniae strains among neonates. Moreover, ESBL-resistance genes were widespread, with the blaSHV gene showing a correlation with increased neonatal mortality. These findings emphasize the urgent need for enhanced infection prevention measures, robust antimicrobial resistance surveillance, innovative treatment strategies, antibiotic stewardship initiatives, further research into resistance transfer mechanisms as well as hierarchical predictors of neonatal mortality. CLINICAL TRIAL NUMBER: Not applicable.202439695444
1211100.9940Molecular characterization of multidrug-resistant Escherichia coli of the phylogroups A and C in dairy calves with meningitis and septicemia. Escherichia coli is an important cause of septicemia (SEPEC) and neonatal meningitis (NMEC) in dairy calves. However, the diversity of virulence profiles, phylogroups, antimicrobial resistance patterns, carriage of integron structures, and fluoroquinolone (FQ) resistance mechanisms have not been fully investigated. Also, there is a paucity of knowledge about the virulence profiles and frequency of potential SEPEC in feces from calves with or without diarrhea. This study aimed to characterize the virulence potential, phylogroups, antimicrobial susceptibility, integron content, and FQ-resistance mechanisms in Escherichia coli isolated from calves with meningitis and septicemia. Additionally, the virulence genes (VGs) and profiles of E. coli isolated from diarrheic and non-diarrheic calves were compared between them and together with NMEC and SEPEC in order to identify shared profiles. Tissue and fluid samples from eight dairy calves with septicemia, four of which had concurrent meningitis, were processed for bacteriology and histopathology. Typing of VGs was assessed in 166 isolates from diverse samples of each calf. Selected isolates were evaluated for antimicrobial susceptibility by the disk diffusion test. Phylogroups, integron gene cassettes cartography, and FQ-resistance determinants were analyzed by PCR, sequencing, and bioinformatic tools. Furthermore, 109 fecal samples and 700 fecal isolates from dairy calves with or without diarrhea were evaluated to detect 19 VGs by uniplex PCR. Highly diverse VG profiles were characterized among NMEC and SEPEC isolates, but iucD was the predominant virulence marker. Histologic lesions in all calves supported their pathogenicity. Selected isolates mainly belonged to phylogroups A and C and showed multidrug resistance. Classic (dfrA17 and arr3-dfrA27) and complex (dfrA17-aadA5::ISCR1::bla(CTX-M-2)) class 1 integrons were identified. Target-site mutations in GyrA (S83L and D87N) and ParC (S80I) encoding genes were associated with FQ resistance. The VGs detected more frequently in fecal samples included f17G (50%), papC (30%), iucD (20%), clpG (19%), eae (16%), and afaE-8 (13%). Fecal isolates displaying the profiles of f17 or potential SEPEC were found in 25% of calves with and without diarrhea. The frequency of E. coli VGs and profiles did not differ between both groups (p > 0.05) and were identical or similar to those found in NMEC and SEPEC. Overall, multidrug-resistant E. coli isolates with diverse VG profiles and belonging to phylogroups A and C can be implicated in natural cases of meningitis and septicemia. Their resistance phenotypes can be partially explained by class 1 integron gene cassettes and target-site mutations in gyrA and parC. These results highlight the value of antimicrobial resistance surveillance in pathogenic bacteria isolated from food-producing animals. Besides, calves frequently shed potential SEPEC in their feces as commensals ("Trojan horse"). Thus, these bacteria may be disseminated in the farm environment, causing septicemia and meningitis under predisposing factors.202234982979
2115110.9940Assessment of carbapenemase genes and antibiotic resistance profiles in ceftazidime-avibactam resistant Klebsiella pneumoniae isolates: A single-center cross-sectional study. BACKGROUND: Carbapenem-resistant Klebsiella pneumoniae (CRKp) is an urgent global health threat due to its rapid spread and limited treatment options. Ceftazidime-avibactam exhibits broad efficacy against gram-negative bacteria, including CRKp; however, emerging resistance to this agent is increasingly reported. Understanding the prevalence of ceftazidime-avibactam resistance and the underlying carbapenemase genes is critical for optimizing antimicrobial stewardship and guiding clinical management. This study aimed to determine the prevalence of ceftazidime avibactam resistance among CRKp isolates collected from various clinical specimens, and to analyze their associated carbapenemase genes and antibiotic resistance profiles. METHODS: This cross-sectional study analyzed 312 K pneumoniae isolates obtained from various clinical specimens of hospitalized patients at a tertiary care hospital in Turkey. Antibiotic susceptibility testing was performed using the disk diffusion method for ceftazidime-avibactam and broth microdilution for both colistin and ceftazidime-avibactam. Molecular detection of carbapenemase genes was carried out using polymerase chain reaction. RESULTS: Ceftazidime-avibactam resistance was identified in 21.5% (67/312) of CRKp isolates. Among these isolates, 37.3% harbored both OXA-48 and NDM genes, 13.4% carried NDM alone, 10.4% carried OXA-48 alone, and 38.8% lacked these genes. The majority of resistant isolates originated from urine (31.3%), followed by tracheal aspirate (29.9%), and blood (22.4%) specimens. The prevalence of colistin susceptibility among ceftazidime-avibactam-resistant CRKp isolates was 56.7%. CONCLUSIONS: The coexistence of NDM and OXA-48 genes is a major contributor to ceftazidime-avibactam resistance in CRKp isolates, particularly in urinary and respiratory tract infections. These findings underscore the need for ongoing surveillance and tailored antibiotic stewardship programs to control the spread of resistance in hospital settings.202541088587
1480120.9939Prospective observational pilot study of the T2Resistance panel in the T2Dx system for detection of resistance genes in bacterial bloodstream infections. Early initiation of antimicrobial therapy targeting resistant bacterial pathogens causing sepsis and bloodstream infections (BSIs) is critical for a successful outcome. The T2Resistance Panel (T2R) detects the following resistance genes within organisms that commonly cause BSIs directly from patient blood samples: bla(KPC), bla(CTXM-14/15), bla(NDM)/bla(/IMP)/bla(VIM), bla(AmpC), bla(OXA), vanA, vanB, and mecA/mecC. We conducted a prospective study in two major medical centers for the detection of circulating resistance genes by T2R in patients with BSIs. T2R reports were compared to antimicrobial susceptibility testing (AST), phenotypic identification, and standard molecular detection assays. Among 59 enrolled patients, 25 resistance genes were identified: bla(KPC) (n = 10), bla(NDM)/bla(/IMP)/bla(VIM) (n = 5), bla(CTXM-14/15) (n = 4), bla(AmpC) (n = 2), and mecA/mecC (n = 4). Median time-to-positive-T2R in both hospitals was 4.4 hours [interquartile range (IQR): 3.65-4.97 hours] in comparison to that for positive blood cultures with final reporting of AST of 58.34 h (IQR: 45.51-111.2 hours; P < 0.0001). The sensitivity of T2R to detect the following genes in comparison to AST was 100% for bla(CTXM-14/15), bla(NDM)/bla(/)(IMP)/bla(VIM), bla(AmpC), mecA/mecC and 87.5% for bla(KPC). When monitored for the impact of significant antimicrobial changes, there were 32 events of discontinuation of unnecessary antibiotics and 17 events of escalation of antibiotics, including initiation of ceftazidime/avibactam in six patients in response to positive T2R results for bla(KPC). In summary, T2R markers were highly sensitive for the detection of drug resistance genes in patients with bacterial BSIs, when compared with standard molecular resistance detection systems and phenotypic identification assays while significantly reducing by approximately 90% the time to detection of resistance compared to standard methodology and impacting clinical decisions for antimicrobial therapy. IMPORTANCE: This is the first reported study to our knowledge to identify key bacterial resistance genes directly from the bloodstream within 3 to 5 hours in patients with bloodstream infections and sepsis. The study further demonstrated a direct effect in modifying initial empirical antibacterial therapy in response to T2R signal to treat resistant bacteria causing bloodstream infections and sepsis.202438456690
2101130.9939Antibiotic resistance genes circulating in Nigeria: a systematic review and meta-analysis from the One Health perspective. BACKGROUND: The misuse of antibiotics in developing countries has created serious threats to public healthcare systems and reduced treatment options. Multidrug-resistant bacteria harbour antibiotic resistance genes that help them subdue the effectiveness of several available antibiotics. This review aimed to assess antimicrobial resistance genes circulating in Nigeria via a systematic review and meta-analysis. METHODS: A comprehensive literature search was performed using five electronic databases: PubMed, Web of Science, Scopus, Google Search, and African Journals Online (AJOL). Articles related to antibiotic resistance genes in Nigeria, published between January 1, 2015 and October 31, 2024, were included. The Newcastle-Ottawa scale (NOS) was used to assess the risk of bias. The meta-analysis for random effects was performed to determine the proportions and pooled prevalence of the resistance genes from the various One Health domains, as well as heterogeneity in the data, using R software (Version 4.3.3) and the metaprop package. RESULTS: Of the 762 articles retrieved, 56 (humans [n = 33], animals [n = 8], environment [n = 12], human/animal [n = 1], and human/animal/environment [n = 2]) from the six geopolitical zones in Nigeria met the inclusion criteria. The extended-spectrum beta-lactamase (ESBL) gene with the highest pooled prevalence was blaSHV (24.0% [95% CI: 12.0–44.0]), followed by blaCTX-M (23.0% [95% CI: 14.0–37.0]), and the least was blaTEM (18.0% [95% CI: 8.0–37.0]). Among the carbapenemase genes, blaKPC (33.0% [95% CI: 7.0–76.0]) was the most prevalent, followed by blaNDM (21.0% [95% CI: 9.0–41.0]), blaOXA (11.0% [95% CI: 2.0–46.0]) and the least was blaVIM (9.0% [95% CI: 3.0–26.0]). The mecA gene also had a high pooled prevalence (51.0% [95% CI: 14.0–86.0]). The pooled prevalence of the erm, sul, tet, and qnr genes ranged from 19.0% (95% CI: 8.0–38.0) to 27.0% (95% CI: 13.0–47.0). Some antibiotic resistance genes were shared among the three domains. CONCLUSION: This systematic review and meta-analysis has demonstrated the co-existence of antibiotic resistance genes among bacteria causing infection in Nigeria, via the One Health approach. There is a need for future research on the circulation of antibiotic resistance genes in developing countries using internationally approved approaches to track down this menace. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12920-025-02163-y.202540619397
1424140.9939Source-tracking ESBL-producing bacteria at the maternity ward of Mulago hospital, Uganda. INTRODUCTION: Escherichia coli, Klebsiella pneumoniae and Enterobacter (EKE) are the leading cause of mortality and morbidity in neonates in Africa. The management of EKE infections remains challenging given the global emergence of carbapenem resistance in Gram-negative bacteria. This study aimed to investigate the source of EKE organisms for neonates in the maternity environment of a national referral hospital in Uganda, by examining the phenotypic and molecular characteristics of isolates from mothers, neonates, and maternity ward. METHODS: From August 2015 to August 2016, we conducted a cross-sectional study of pregnant women admitted for elective surgical delivery at Mulago hospital in Kampala, Uganda; we sampled (nose, armpit, groin) 137 pregnant women and their newborns (n = 137), as well as health workers (n = 67) and inanimate objects (n = 70 -beds, ventilator tubes, sinks, toilets, door-handles) in the maternity ward. Samples (swabs) were cultured for growth of EKE bacteria and isolates phenotypically/molecularly investigated for antibiotic sensitivity, as well as β-lactamase and carbapenemase activity. To infer relationships among the EKE isolates, spatial cluster analysis of phenotypic and genotypic susceptibility characteristics was done using the Ridom server. RESULTS: Gram-negative bacteria were isolated from 21 mothers (15%), 15 neonates (11%), 2 health workers (3%), and 13 inanimate objects (19%); a total of 131 Gram-negative isolates were identified of which 104 were EKE bacteria i.e., 23 (22%) E. coli, 50 (48%) K. pneumoniae, and 31 (30%) Enterobacter. Carbapenems were the most effective antibiotics as 89% (93/104) of the isolates were susceptible to meropenem; however, multidrug resistance was prevalent i.e., 61% (63/104). Furthermore, carbapenemase production and carbapenemase gene prevalence were low; 10% (10/104) and 6% (6/104), respectively. Extended spectrum β-lactamase (ESBL) production occurred in 37 (36%) isolates though 61 (59%) carried ESBL-encoding genes, mainly blaCTX-M (93%, 57/61) implying that blaCTX-M is the ideal gene for tracking ESBL-mediated resistance at Mulago. Additionally, spatial cluster analysis revealed isolates from mothers, new-borns, health workers, and environment with similar phenotypic/genotypic characteristics, suggesting transmission of multidrug-resistant EKE to new-borns. CONCLUSION: Our study shows evidence of transmission of drug resistant EKE bacteria in the maternity ward of Mulago hospital, and the dynamics in the ward are more likely to be responsible for transmission but not individual mother characteristics. The high prevalence of drug resistance genes highlights the need for more effective infection prevention/control measures and antimicrobial stewardship programs to reduce spread of drug-resistant bacteria in the hospital, and improve patient outcomes.202337289837
1258150.9939Occurrence of antimicrobial resistance and antimicrobial resistance genes in methicillin-resistant Staphylococcus aureus isolated from healthy rabbits. BACKGROUND AND AIM: Methicillin-resistant globally, Staphylococcus aureus (MRSA) is a major cause of disease in both humans and animals. Several studies have documented the presence of MRSA in healthy and infected animals. However, there is less information on MRSA occurrence in exotic pets, especially healthy rabbits. This study aimed to look into the antimicrobial resistance profile, hidden antimicrobial-resistant genes in isolated bacteria, and to estimate prevalence of MRSA in healthy rabbits. MATERIALS AND METHODS: Two-hundreds and eighteen samples, including 42 eyes, 44 ears, 44 oral, 44 ventral thoracic, and 44 perineal swabs, were taken from 44 healthy rabbits that visited the Prasu-Arthorn Animal Hospital, in Nakornpathom, Thailand, from January 2015 to March 2016. The traditional methods of Gram stain, mannitol fermentation, hemolysis on blood agar, catalase test, and coagulase production were used to confirm the presence of Staphylococcus aureus in all specimens. All bacterial isolates were determined by antimicrobial susceptibility test by the disk diffusion method. The polymerase chain reaction was used to identify the antimicrobial-resistant genes (blaZ, mecA, aacA-aphD, msrA, tetK, gyrA, grlA, and dfrG) in isolates of MRSA with a cefoxitin-resistant phenotype. RESULTS: From 218 specimens, 185 S. aureus were isolated, with the majority of these being found in the oral cavity (29.73%) and ventral thoracic area (22.7%), respectively. Forty-seven (25.41%) MRSAs were found in S. aureus isolates, with the majority of these being found in the perineum (16, 34.04%) and ventral thoracic area (13, 27.66%) specimens. Among MRSAs, 29 (61.7%) isolates were multidrug-resistant (MDR) strains. Most of MRSA isolates were resistant to penicillin (100%), followed by ceftriaxone (44.68%) and azithromycin (44.68%). In addition, these bacteria contained the most drug-resistance genes, blaZ (47.83%), followed by gyrA (36.17%) and tetK (23.4%). CONCLUSION: This study revealed that MRSA could be found even in healthy rabbits. Some MRSAs strains were MDR-MRSA, which means that when an infection occurs, the available antibiotics were not effective in treating it. To prevent the spread of MDR-MRSA from pets to owners, it may be helpful to educate owners about effective prevention and hygiene measures.202236590129
2267160.9939MOLECULAR CHARACTERIZATION AND DETECTION OF MULTIDRUGRESISTANT GENE IN BACTERIAL ISOLATES CAUSING LOWER RESPIRATORY TRACT INFECTIONS (LRTI) AMONG HIV/AIDS PATIENTS ON HIGHLY ACTIVE ANTIRETROVIRAL THERAPY (HAART) IN UYO, SOUTH-SOUTH NIGERIA. BACKGROUND: Antibiotic-resistant genes (ARGs) pose a significant challenge in modern medicine, rendering infections increasingly difficult to treat as bacteria acquire mechanisms to resist antibiotics. Addressing ARGs necessitates a multifaceted approach, encompassing surveillance efforts to monitor their presence and the development of strategies aimed at managing and curbing the spread of antibiotic resistance. Hence, this study characterized the genetic determinants of antibiotic resistance among isolates responsible for Lower Respiratory Tract Infections (LRTIs) in People Living with HIV/AIDS (PLWHA) in Uyo. METHODS: Sputum samples were collected from 61 LRTI suspects, with bacterial isolates identified using VITEK-2 technology. Polymerase chain reaction assays were employed to detect resistance genes within the isolates. RESULTS: Results revealed a bacterial etiology in 39.3% of the samples, with a majority (79.2%) originating from St. Luke Hospital, Anua (SLHA), and the remainder (20.8%) from the University of Uyo Teaching Hospital (UUTH). Staphylococcus aureus emerged as the predominant isolate (46.6%), while resistance was notably high against Gentamicin and Sulphamethazole/Trimethoprim. Conversely, Azithromycin, imipenem, clindamycin, erythromycin, and ceftriaxone displayed relatively lower resistance levels across all isolates. Notably, four resistance genes CTX-M, Aac, KPC, and MecA were identified, with CTX-M detected in all multidrug-resistant isolates. This underscores the predominantly community-acquired nature of resistance as conferred by CTX-M. CONCLUSION: In conclusion, this study underscores the critical importance of continued vigilance and proactive measures in combating antibiotic resistance, particularly within vulnerable populations such as PLWHA. By elucidating the genetic mechanisms underlying antibiotic resistance, informed targeted interventions can be mitigated to curb threats posed by multidrug-resistant bacteria in clinical settings.202440385712
861170.9939The Prevalence Rates of Colistin Resistance Among Third-Generation Cephalosporin-Resistant E. coli Isolates From Thai Patients. Drug-resistant infections, such as colistin resistance, are reportedly increasing due to the inappropriate use of antibiotics, lack of good control, and the use of excessive quantities of antibiotics. Colistin resistance has been observed in bacteria of the order Enterobacterales exhibiting resistance to third-generation cephalosporins or carbapenems. Currently, the prevalence of colistin resistance in third-generation cephalosporin-resistant E. coli obtained from patients at Nopparat Rajathanee Hospital, Thailand, in 2023 was determined by broth microdilution. Among 343 isolates, 1.45% (95% CI: 0.19%-2.73%, n = 5/343) exhibited a minimum inhibitory concentration (MIC) of colistin between 4 and 8 μg/mL, indicating colistin-resistant E. coli. Nevertheless, five isolates were positive for resistant genes by multiplex PCR: two isolates for mcr-1, two isolates for mcr-3, and one isolate for both mcr-1 and mcr-3. This study reveals crucial data on resistance genes, informing surveillance of antibiotic resistance, treatment decisions, and public health initiatives to combat resistant bacteria.202541170286
1333180.9939Virulence-encoding genes related to extraintestinal pathogenic E. coli and multidrug resistant pattern of strains isolated from neonatal calves with different severity scores of umbilical infections. Umbilical infections in calves comprise a major cause of neonatal mortality and have been related to a variety of microorganisms. E. coli is an opportunistic enteropathogen characterized by a diversity of virulence factors (VF). Nonetheless, the gene profiles that encode VF associated with umbilical infections in calves and their effect on the clinical severity remains unclear. In this scenario, microbial identification (with an emphasis on E. coli), was carried out among 150 neonatal calves (≤30 days of age) with umbilical infections, where the omphalopathies were clinically scored as mild, moderate, or severe. Also, a panel of 16 virulence-encoding genes related to extraintestinal pathogenic E. coli (ExPEC) were investigated, i.e., fimbriae/adhesins (sfa/focDEa, papA, papC, afaBC), toxins (hlyA, sat, cnf1, cdt), siderophores (iroN, irp2, iucD, ireA), invasins (ibeA), and serum resistance (ompT, traT, kpsMT II). Bacteria and yeasts isolates were identified using mass spectrometry. Bacteria, yeasts, and fungi were isolated in 94.7% (142/150) of neonatal calves sampled. E. coli was the agent most frequently isolated (59/150 = 39.3%), in pure culture (27/59 = 45.8%) and combined infections (32/59 = 54.2%), although a great variety (n = 83) of other species of microorganisms were identified. Clinical severity scores of 1, 2, and 3 were observed in 32.2% (19/59), 23.7% (14/59), and 44.1% (26/59) of E. coli infections, respectively. The ExPEC genes detected were related to serum resistance (traT, 42/59 = 72.2%; ompT, 35/59 = 59.3%, kpsMTII, 10/59 = 17%), invasins (ibeA, 11/59 = 18.6%), siderophores (iucD, 9/59 = 15.3%; iroN, 8/59 = 13.6%), and adhesins/fimbriae (papA, 8/59 = 13.6%; papC, 15/59 = 9.6%). The presence of each virulence gene was not associated with the case's clinical score. Among all isolates, 89.8% (53/59) showed in vitro resistance to sulfamethoxazole/trimethoprim and 59.3% to ampicillin (35/59), while 94.1% (55/59) revealed a multidrug resistant profile. Great complexity of bacteria, yeast, and fungi species was identified, reinforcing the umbilical infections of neonatal calves as a polymicrobial disorder. The high occurrence of E. coli (39.3%) highlights the role of this pathogen in the etiology of umbilical infections in calves. Furthermore, a panel of ExPEC genes was investigated for the first time among calves that were clinically scored for case severity. The high prevalence of traT and ompT indicates that these serum resistance-related genes could be used as biomarkers for further investigations of ExPEC isolates from umbilical infections. Our results contribute to the etiological investigation, clinical severity scoring, antimicrobial resistance pattern, and virulence-related to ExPEC genes involved in umbilical infections of neonatal calves.202336427660
1448190.9939Molecular characteristics of carbapenem-resistant Acinetobacter spp. from clinical infection samples and fecal survey samples in Southern China. BACKGROUND: Carbapenem resistance among Acinetobacter species has become a life-threatening problem. As a last resort in the treatment of gram-negative bacteria infection, resistance to colistin is also a serious problem. The aim of study was to analyze the mechanism of resistance and perform genotyping of carbapenem-resistant Acinetobacter from clinical infection and fecal survey samples in Southern China. METHODS: One hundred seventy and 74 carbapenem-resistant Acinetobacter were isolated from clinical infection samples and fecal survey samples, respectively. We detected the related genes, including carbapenemase genes (bla(KPC), bla(IMP), bla(SPM), bla(VIM), bla(NDM), bla(OXA-23-like), bla(OXA-24/40-like), bla(OXA-51-like), and bla(OXA-58-like)), colistin resistance-related genes (mcr-1, mcr-2, mcr-3, mcr-4, and mcr-5), a porin gene (carO), efflux pump genes (adeA, adeB, adeC, adeI, adeJ, and adeK), mobile genetic element genes (intI1, intI2, intI3, tnpU, tnp513, IS26, ISAba1, and ISAba125), and the integron variable region. Genotyping was analyzed by enterobacterial repetitive intergenic consensus (ERIC)-PCR and dendrogram cluster analysis. RESULTS: Among the 244 carbapenem-resistant Acinetobacter, the common carbapenemase-positive genes included the following: bla(OXA-51-like), 183 (75.00%); bla(OXA-23-like), 174 (71.30%); bla(NDM-1), 57 (23.40%); and bla(OXA-58-like), 30 (12.30%). The coexistence of mcr-1 and bla(NDM-1) in five strains of A. junii was found for the first time. Eleven distinct carO gene variants were detected in 164 (67.20%) strains, and ten novel variants, which shared 92-99% identity with sequences in the Genbank database, were first reported. Efflux system genes were present in approximately 70% of the isolates; adeABC and adeIJK were observed in 76.23 and 72.13%, respectively. Class 1 integrons were detected in 180 (73.80%) strains and revealed that four gene cassette arrays contained 11 distinct genes. The genotyping by ERIC-PCR demonstrated a high genetic diversity of non-baumannii Acinetobacter, and greater than 90% similarity to A. baumannii. CONCLUSIONS: The bla(NDM-1) gene was identified in up to 77% of the carbapenem-resistant Acinetobacter isolated from fecal survey samples, indicating that the gut might be a reservoir of resistant opportunistic bacteria. Intestinal bacteria can be transmitted through the fecal-hand, which is a clinical threat, thus, the monitoring of carbapenem-resistant bacteria from inpatients' feces should be improved, especially for patients who have been using antibiotics for a long time.201931660862