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194500.8944Emergence of NDM-1-producing Raoultella ornithinolytica from reservoir water in Northeast Thailand. BACKGROUND AND AIM: Antibiotic resistance is a major global health threat. The increasing prevalence of drug-resistant bacteria poses a serious challenge to the effective treatment of infections in both humans and animals. Water is a major source of human and animal exposure to bacteria, and the presence of drug-resistant bacteria in water could present a severe threat to public health and animal production. This study investigated the presence of drug-resistant bacteria in Lam Pao Dam (LPD) water in Kalasin, Thailand. MATERIALS AND METHODS: Ampicillin-resistant strains were obtained from LPD water and identified using 16s rDNA sequencing. Antibiotic resistance genes were detected by polymerase chain reaction using specific primers. The presence of antibiotic-resistant bacteria was evaluated using 16s amplicon analysis. The minimum inhibitory concentration (MIC) of Raoultella ornithinolytica strains against antibiotics was determined. RESULTS: A total of 12 R. ornithinolytica, 4 Bacillus cereus, and 4 Enterococcus faecalis isolates were resistant to ampicillin. Almost all R. ornithinolytica strains harbored bla(SHV) and bla(OXA) genes, and two strains also harbored the bla(NDM-1) gene. All four E. faecalis strains harbored the bla(IMP) gene. The most abundant species in the LPD sample was Exiguobacterium indicum, followed by E. faecalis and R. ornithinolytica. The MICs of 10 R. ornithinolytica strains against five antibiotics revealed that all strains were resistant to ampicillin but susceptible to meropenem, doripenem, ertapenem, and imipenem. CONCLUSION: These findings suggest a high prevalence of drug-resistant bacteria in LPD water. This is a cause for concern, as it could spread antibiotic-resistant infections in the community.202338152267
217010.8927Drug 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
353920.8925Exposure Levels of Airborne Fungi, Bacteria, and Antibiotic Resistance Genes in Cotton Farms during Cotton Harvesting and Evaluations of N95 Respirators against These Bioaerosols. The USA is the third-leading cotton-producing country worldwide and cotton farming is common in the state of Georgia. Cotton harvest can be a significant contributor to airborne microbial exposures to farmers and nearby rural communities. The use of respirators or masks is one of the viable options for reducing organic dust and bioaerosol exposures among farmers. Unfortunately, the OSHA Respiratory Protection Standard (29 CFR Part 1910.134) does not apply to agricultural workplaces and the filtration efficiency of N95 respirators was never field-tested against airborne microorganisms and antibiotic resistance genes (ARGs) during cotton harvesting. This study addressed these two information gaps. Airborne culturable microorganisms were sampled using an SAS Super 100 Air Sampler in three cotton farms during cotton harvesting, and colonies were counted and converted to airborne concentrations. Genomic DNA was extracted from air samples using a PowerSoil(®) DNA Isolation Kit. A series of comparative critical threshold (2(-ΔΔCT)) real-time PCR was used to quantify targeted bacterial (16S rRNA) genes and major ARGs. Two N95 facepiece respirator models (cup-shaped and pleated) were evaluated for their protection against culturable bacteria and fungi, total microbial load in terms of surface ATP levels, and ARGs using a field experimental setup. Overall, culturable microbial exposure levels ranged between 10(3) and 10(4) CFU/m(3) during cotton harvesting, which was lower when compared with bioaerosol loads reported earlier during other types of grain harvesting. The findings suggested that cotton harvesting works can release antibiotic resistance genes in farm air and the highest abundance was observed for phenicol. Field experimental data suggested that tested N95 respirators did not provide desirable >95% protections against culturable microorganisms, the total microbial load, and ARGs during cotton harvesting.202337375063
140030.8923Comparative genomic analysis of Escherichia coli strains obtained from continuous imipenem stress evolution. The carbapenem-resistant Escherichia coli has aroused increasing attention worldwide, especially in terms of imipenem (IMP) resistance. The molecular mechanism of IMP resistance remains unclear. This study aimed to explore the resistance mechanisms of IMP in E. coli. Susceptible Sx181-0-1 strain was induced into resistance strains by adaptive laboratory evolution. The drug resistance spectrum was measured using the disk diffusion and microbroth dilution methods. Whole-genome sequencing and resequencing were used to analyze the nonsynonymous single-nucleotide polymorphisms (nsSNPs) between the primary susceptible strain and resistant strains. The expression levels of these genes with nsSNPs were identified by real-time quantitative PCR (RT-qPCR). Resistance phenotype appeared in the induced 15th generation (induction time = 183 h). Sx181-32 and Sx181-256, which had the minimum inhibitory concentrations of IMP of 8 and 64 µg ml-1, were isolated during continuous subculture exposed to increasing concentrations of IMP, respectively. A total of 19 nsSNPs were observed both in Sx181-32 and Sx181-256, distributed in rpsU, sdaC, zwf, ttuC, araJ, dacC, mrdA, secF, dacD, lpxD, mrcB, ftsI, envZ, and two unknown function genes (orf01892 and orf01933). Among these 15 genes, five genes (dacC, mrdA, lpxD, mrcB, and ftsI) were mainly involved in cell wall synthesis. The mrdA (V338A, L378P, and M574I) and mrcB (P784L, A736V, and T708A) had three amino acid substitutions, respectively. The expression levels of rpsU, ttuC, and orf01933 were elevated in both Sx181-32 and Sx181-256 compared to Sx181-0-1. The expression levels of these genes were elevated in Sx181-256, except for araJ. Bacteria developed resistance to antimicrobials by regulating various biological processes, among which the most involved is the cell wall synthesis (dacC, mrdA, lpxD, mrcB, and ftsI). The combination mutations of mrdA, envZ, and ftsI genes may increase the resistance to IMP. Our study could improve the understanding of the molecular mechanism of IMP resistance in E. coli.202235147175
125640.8918Prevalence of antimicrobial resistant genes in Bacteroides spp. isolated in Oita Prefecture, Japan. INTRODUCTION: Bacteroides spp. are the most common anaerobic bacteria isolated from the human gastrointestinal tract. Several resistant genes are present in Bacteroides spp. However, most studies have focused on the prevalence of the cfiA gene in Bacteroides fragilis alone. We assessed the susceptibility to antimicrobial agents and the prevalence of cepA, cfiA, cfxA, ermF, nim, and tetQ genes in Bacteroides strains isolated from clinical specimens in our hospital. METHODS: We isolated 86 B. fragilis and 58 non-fragilis Bacteroides strains from human clinical specimens collected from January 2011 to November 2021. Resistance against piperacillin (PIPC), cefotaxime (CTX), cefepime (CFPM), meropenem (MEPM), clindamycin, and minocycline was determined. RESULTS: The resistant rates of penicillins and cephalosporins in non-fragilis isolates were significantly higher than those in B. fragilis isolates. In B. fragilis isolates, the resistant rates of PIPC, CTX, and CFPM in cfxA-positive isolates were significantly higher than those in cfxA-negative isolates (71% vs. 16%, 77% vs. 19%, and 77% vs. 30%, respectively). Thirteen B. fragilis isolates harbored the cfiA gene, two of which were resistant to MEPM. Six of the 13 cfiA-positive B. fragilis isolates were heterogeneously resistant to MEPM. CONCLUSION: It is important to evaluate the use of MEPM as empirical therapy for Bacteroides spp. infections, considering the emergence of carbapenem resistance during treatment, existence of MEPM-resistant strains, and heterogeneous resistance.202336473684
140750.8916World Health Organization priority antimicrobial resistance in Enterobacterales, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecium healthcare-associated bloodstream infections in Brazil (ASCENSION): a prospective, multicentre, observational study. BACKGROUND: Carbapenem-resistant Enterobacterales (CRE), Acinetobacter baumannii (CRAB), Pseudomonas aeruginosa (CRPA), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE) are listed by World Health Organization (WHO) as priority antimicrobial-resistant bacteria. Data on WHO Priority Antimicrobial resistance Phenotype (WPAP) bacteria from low- and middle-income countries are scarce. In this study, we investigated the occurrence of WPAP in healthcare-associated bloodstream infections (BSI) in Brazil, an upper-middle-income country in South America. METHODS: ASCENSION was a prospective, multicentre, observational study conducted in 14 hospitals from four of five Brazilian regions. Enterobacterales, A. baumannii, P. aeruginosa, S. aureus and E. faecium BSIs in hospitalised patients were analysed. The primary outcome was the frequency of WPAP among all bacteria of interest. Secondary outcomes were incidence-density of bacteria isolates in hospitalised patients, WPAP proportions within bacterial species, and 28-day mortality. PCR for carbapenemase genes was performed in carbapenem-resistant Gram-negative bacteria. FINDINGS: Between August 15, 2022, and August 14, 2023, 1350 isolates (1220 BSI episodes) were included. WPAP accounted for 38.8% (n = 524; 95% Confidence Interval 32.0-46.1) of all isolates, with CRE (19.3%) as the most frequent, followed by CRAB (9.6%), MRSA (4.9%), VRE (2.7%), and CRPA (2.4%). Incidence-density of all and WPAP isolates were 1.91 and 0.77/1000 patients-day, respectively. Carbapenem-resistant Klebsiella pneumoniae (CRKP) was the most common CRE, corresponding to 14.2% of all BSIs. A. baumannii isolates presented the highest proportion of WPAP (87.8%). Mortality rates were higher in patients with BSIs by WPAP than non-WPAP isolates. KPC (64.4%) was the predominant carbapenemase in CRE, followed by NDM (28.4%) and KPC + NDM co-production (7.1%). OXA-23 was the most frequent in CRAB. INTERPRETATION: A high frequency of WPAP bacteria, particularly CRKP and CRAB, were found in healthcare-associated BSIs in Brazil, posing them as a major public health problem in this country. FUNDING: National Council for Scientific and Technological Development, Brazil.202539957800
843360.8912Thermoresponsive Nanostructures: From Mechano-Bactericidal Action to Bacteria Release. Overuse of antibiotics can increase the risk of notorious antibiotic resistance in bacteria, which has become a growing public health concern worldwide. Featured with the merit of mechanical rupture of bacterial cells, the bioinspired nanopillars are promising alternatives to antibiotics for combating bacterial infections while avoiding antibacterial resistance. However, the resident dead bacterial cells on nanopillars may greatly impair their bactericidal capability and ultimately impede their translational potential toward long-term applications. Here, we show that the functions of bactericidal nanopillars can be significantly broadened by developing a hybrid thermoresponsive polymer@nanopillar-structured surface, which retains all of the attributes of pristine nanopillars and adds one more: releasing dead bacteria. We fabricate this surface through coaxially decorating mechano-bactericidal ZnO nanopillars with thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm) brushes. Combining the benefits of ZnO nanopillars and PNIPAAm chains, the antibacterial performances can be controllably regulated between ultrarobust mechano-bactericidal action (∼99%) and remarkable bacteria-releasing efficiency (∼98%). Notably, both the mechanical sterilization against the live bacteria and the controllable release for the pinned dead bacteria solely stem from physical actions, stimulating the exploration of intelligent structure-based bactericidal surfaces with persistent antibacterial properties without the risk of triggering drug resistance.202134905683
233870.8912Characterization of disinfectant susceptibility profiles among clinical isolates of Acinetobacter baumannii in Ardabil, Iran. Antimicrobial disinfectants have been extensively used to control hospital-acquired infections worldwide. Prolonged exposure to bacteria could promote resistance to antimicrobial disinfectants. This study evaluated the antimicrobial activity of four commonly used disinfectants; triclosan, chlorhexidine digluconate, benzalkonium chloride, and formaldehyde against Acinetobacter baumannii clinical isolates. This study also determined the prevalence and association of efflux pumps encoding genes qacE, qacED1, emrA, and aceI with tolerance to disinfectants. A total of 100 A. baumannii isolates were included in the current study. The antimicrobial disinfectants' minimum inhibitory concentration (MIC) was determined using an agar dilution method. Genes involved in resistance to disinfectants were investigated by PCR method. The benzalkonium chloride MICs ranged between 32 and 128 μg mL-1, chlorhexidine digluconate 8-64 μg mL-1, triclosan 1-32 μg mL-1, and formaldehyde 128 μg mL-1. Overall, the highest MIC90 value was identified for formaldehyde (128 μg mL-1), followed by benzalkonium chloride and chlorhexidine digluconate (64 μg mL-1, each one) and triclosan (4 μg mL-1). In the present study, the qacE, qacED1, emrA, and aceI genes were found in 91%, 55%, 100%, and 88% of isolates, respectively. The qacG gene was not identified in our A. baumannii isolates. The qacED1 gene was associated with higher MICs for all disinfectants tested (P < 0.05), while the qacE and aceI genes were associated with higher MICs for benzalkonium chloride and chlorhexidine. This study indicated that triclosan is the most effective disinfectant against A. baumannii isolates.202338063878
523380.8911Antibiotic resistance pattern of the allochthonous bacteria isolated from commercially available spices. Spices are often used in dried form, sometimes with significant microbial contamination including pathogenic and food spoilage bacteria. The antibiotic resistance represents an additional risk for food industry, and it is worthy of special attention as spices are important food additives. During our work, we examined the microbiological quality of 50 different spices with cultivation methods on diverse selective media. The identification of the most representative bacteria was carried out using 16S rDNA gene sequence analysis. Antibiotic resistance profiling of twelve identified Bacillus species (B. subtilis subsp. stercoris BCFK, B. licheniformis BCLS, B. siamensis SZBC, B. zhangzhouensis BCTA, B. altitudinis SALKÖ, B. velezensis CVBC, B. cereus SALÖB isolate, B. tequilensis KOPS, B. filamentosus BMBC, B. subtilis subsp. subtilis PRBC2, B. safensis BMPS, and B. mojavensis BCFK2 isolate) was performed using the standard disk-diffusion method against 32 antibiotics. The study showed that the majority resistance was obtained against penicillin G (100%), oxacillin (91.67%), amoxyclav (91.67%), rifampicin (75%), and azithromycin (75%). Our findings suggest that spices harbor multidrug-resistant bacteria.202134401102
537790.8910Synthetic lincosamides iboxamycin and cresomycin are active against ocular multidrug-resistant methicillin-resistant Staphylococcus aureus carrying erm genes. OBJECTIVE: Antimicrobial resistance is a global pandemic that poses a major threat to vision health as ocular bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA), are becoming increasingly resistant to first-line therapies. Here we evaluated the antimicrobial activity of new synthetic lincosamides in comparison to currently used antibiotics against clinical ocular MRSA isolates. METHODS: Antimicrobial susceptibility testing was performed by broth microdilution for two novel synthetic lincosamides (iboxamycin and cresomycin) and eight comparator antibiotics against a collection of 50 genomically characterised ocular MRSA isolates, including isolates harbouring erm genes (n = 25). RESULTS: Both drugs were active against widespread MRSA clonal complexes CC8 and CC5. The MIC(50) and MIC(90) of iboxamycin were 0.06 and 2 mg/L, respectively. Cresomycin (MIC(50) = 0.06 mg/L) also displayed good activity with an in vitro potency four-fold higher (MIC(90) = 0.5 mg/L) than iboxamycin. In isolates harbouring erm genes, MIC(90) were >16, 2, and 0.5 mg/L for clindamycin, iboxamycin, and cresomycin, respectively. The in vitro potencies of iboxamycin and cresomycin were similar or higher than that of comparator agents and were not impacted by multidrug-resistance phenotypes or by the presence of erm genes when compared with clindamycin. CONCLUSIONS: Our results demonstrate that iboxamycin and cresomycin display potent in vitro activity against ocular MRSA isolates, including multidrug-resistant isolates harbouring erm genes.202439293511
1275100.8909Analysis of the Frequency, Antibiotic Susceptibility, and Related Genes among Foodborne Pathogenic Bacteria Isolated from Hospital Refrigerators in Tehran, Iran. BACKGROUND: Hospital refrigerators as essential food storage can be important source of food contamination. We aimed to investigate the frequency and antibiotic susceptibility of the pathogenic bacteria in three hospital refrigerators in Tehran. METHODS: This study was performed on 254 samples, collected from 60 refrigerators of the various wards of three hospitals, A, B, and C, in Tehran, Iran from 2020 to 2021. Following isolation and identification of isolates, the antibiotic susceptibility pattern was determined. PCR-based assays were used to screen the presence of antibiotic resistance genes of resistant isolates. RESULTS: From 254 collected samples, 236 samples (92.9%) were contaminated. Most strains were isolated from refrigerators with poorly cleaned, temperatures above 8 °C in non-critical wards. Most bacteria belonging to Enterobacteriaceae (68.8%), followed by Staphylococcus (11.9%), and Enterococcus (10.6%), while the frequency of non-Enterobacteriaceae isolates was 8.9%. The highest antibiotic resistant bacteria were in extended spectrum beta-lactamase (ESBL) 9.7%, vancomycin-resistant enterococci (VRE) 5.3%, methicillin-resistant S. epidermidis (MRSE) 0.4%, and methicillin-resistant S. aureus (MRSA) 0.4%, respectively. The bla (OXA-48), bla (CTX), and bcla (TEM) genes were found only in 10% of Enterobacteriaceae isolates. The bla (OXA-51) gene was found in all non-Enterobacteriaceae isolates. The vanA and mecA genes were detected in antibiotic-resistant Enterococcus and Staphylococcus. CONCLUSION: Our findings suggests major concern about cross-contamination and the emergence of antibiotic-resistant isolates as a potential health threat with hospital refrigerators origin. More attention to hospital refrigerators cleaning is necessary to prevent foodborne diseases and nosocomial infections.202438919309
6076110.8909Isolation and identification of mucin-degrading bacteria originated from human faeces and their potential probiotic efficacy according to host-microbiome enterotype. AIM: Mucin-degrading bacteria are known to be beneficial for gut health. We aimed to isolate human-derived mucin-degrading bacteria and identify potential probiotic characteristics and their effects on the bacterial community and short-chain fatty acid (SCFA) production according to three different enterotypes of the host. METHODS AND RESULTS: Bacteria with mucin decomposition ability from human faeces were isolated and identified by 16S rRNA sequencing and MALDI-TOF. Heat resistance, acid resistance, antibiotic resistance, and antibacterial activity were analysed in the selected bacteria. Their adhesion capability to the Caco-2 cell was determined by scanning electron microscopy. Their ability to alter the bacterial community and SCFA production of the isolated bacteria was investigated in three enterotypes. The three isolated strains were Bifidobacterium(Bif.) animalis SPM01 (CP001606.1, 99%), Bif. longum SPM02 (NR_043437.1, 99%), and Limosilactobacillus(L.) reuteri SPM03 (CP000705.1, 99%) deposited in Korean Collection for Type Culture (KCTC-18958P). Among them, Bif. animalis exhibited the highest mucin degrading ability. They exhibited strong resistance to acidic conditions, moderate resistance to heat, and the ability to adhere tightly to Caco-2 cells. Three isolated mucin-degrading bacteria incubation increased Lactobacillus in the faecal bacteria from Bacteroides and Prevotella enterotypes. However, only L. reuteri elevated Lactobacillus in the faecal bacteria from the Ruminococcus enterotype. B. longum and B. animalis increased the α-diversity in the Ruminococcus enterotype, while their incubation with other intestinal types decreased the α-diversity. Bifidobacterium animalis and L. reuteri increased the butyric acid level in faecal bacteria from the Prevotella enterotype, and L. reuteri elevated the acetic acid level in those from the Ruminococcus enterotype. However, the overall SCFA changes were minimal. CONCLUSIONS: The isolated mucin-degrading bacteria act as probiotics and modulate gut microbiota and SCFA production differently according to the host's enterotypes. SIGNIFICANCE AND IMPACT OF STUDY: Probiotics need to be personalized according to the enterotypes in clinical application.202235365862
2193120.8908Distributions and Types of Multidrug-Resistant Acinetobacter baumannii in Different Departments of a General Hospital. BACKGROUND: Acinetobacter baumannii is the most prevalent strain in hospitals and different clinical departments. OBJECTIVES: The current study aimed to investigate the genetic characteristics and resistance mechanisms of A. baumannii isolated from clinical samples in Shaoxing people's hospital affiliated to Zhejiang University, Shaoxing, China. PATIENTS AND METHODS: Acinetobacter baumannii strains were isolated from blood, phlegm and skin of the patients hospitalized in different departments as respiratory medicine, plastic surgery and intensive care unit (ICU). Multilocus sequence typing (MLST) was used to characterize the isolates. Kirby-Bauer test was used to evaluate antibiotic resistance of the bacteria. The expression of resistance inducing genes was detected by reverse transcription polymerase chain reaction (RT-PCR). The results were analyzed and compared. RESULTS: Two bacterial types, ST208, and ST218, were identified in all 140 samples. The ST208 mainly came from ICU and department of respiratory medicine, while ST218 from department of plastic surgery; 70.21% of ST208 and 84.78% of ST218 were carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-susceptible Acinetobacter baumannii (CSAB), respectively. Multidrug-resistance genes in CRAB isolated from the hospital mainly included, oxa-23, oxa-5, intl 1 and qaceΔ1-sul 1. Besides, the highest and lowest antibiotic resistance was observed in the strains isolated from blood samples and wounds, respectively. CONCLUSIONS: The distribution of AB varies in different clinical departments and samples. In the hospital under study, the main types of AB were ST208 and ST218. The genes which affect the ability of antibiotic-resistance were oxa-23, oxa-51, intl 1 and qaceΔ1-sul 1.201526487921
2300130.8908Determining 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
7080140.8908Antibiotics, bacteria, and antibiotic resistance genes: aerial transport from cattle feed yards via particulate matter. BACKGROUND: Emergence and spread of antibiotic resistance has become a global health threat and is often linked with overuse and misuse of clinical and veterinary chemotherapeutic agents. Modern industrial-scale animal feeding operations rely extensively on veterinary pharmaceuticals, including antibiotics, to augment animal growth. Following excretion, antibiotics are transported through the environment via runoff, leaching, and land application of manure; however, airborne transport from feed yards has not been characterized. OBJECTIVES: The goal of this study was to determine the extent to which antibiotics, antibiotic resistance genes (ARG), and ruminant-associated microbes are aerially dispersed via particulate matter (PM) derived from large-scale beef cattle feed yards. METHODS: PM was collected downwind and upwind of 10 beef cattle feed yards. After extraction from PM, five veterinary antibiotics were quantified via high-performance liquid chromatography with tandem mass spectrometry, ARG were quantified via targeted quantitative polymerase chain reaction, and microbial community diversity was analyzed via 16S rRNA amplification and sequencing. RESULTS: Airborne PM derived from feed yards facilitated dispersal of several veterinary antibiotics, as well as microbial communities containing ARG. Concentrations of several antibiotics in airborne PM immediately downwind of feed yards ranged from 0.5 to 4.6 μg/g of PM. Microbial communities of PM collected downwind of feed yards were enriched with ruminant-associated taxa and were distinct when compared to upwind PM assemblages. Furthermore, genes encoding resistance to tetracycline antibiotics were significantly more abundant in PM collected downwind of feed yards as compared to upwind. CONCLUSIONS: Wind-dispersed PM from feed yards harbors antibiotics, bacteria, and ARGs.201525633846
7131150.8906Longitudinal study of the short- and long-term effects of hospitalisation and oral trimethoprim-sulfadiazine administration on the equine faecal microbiome and resistome. BACKGROUND: Hospitalisation and antimicrobial treatment are common in horses and significantly impact the intestinal microbiota. Antimicrobial treatment might also increase levels of resistant bacteria in faeces, which could spread to other ecological compartments, such as the environment, other animals and humans. In this study, we aimed to characterise the short- and long-term effects of transportation, hospitalisation and trimethoprim-sulfadiazine (TMS) administration on the faecal microbiota and resistome of healthy equids. METHODS: In a longitudinal experimental study design, in which the ponies served as their own control, faecal samples were collected from six healthy Welsh ponies at the farm (D0-D13-1), immediately following transportation to the hospital (D13-2), during 7 days of hospitalisation without treatment (D14-D21), during 5 days of oral TMS treatment (D22-D26) and after discharge from the hospital up to 6 months later (D27-D211). After DNA extraction, 16S rRNA gene sequencing was performed on all samples. For resistome analysis, shotgun metagenomic sequencing was performed on selected samples. RESULTS: Hospitalisation without antimicrobial treatment did not significantly affect microbiota composition. Oral TMS treatment reduced alpha-diversity significantly. Kiritimatiellaeota, Fibrobacteres and Verrucomicrobia significantly decreased in relative abundance, whereas Firmicutes increased. The faecal microbiota composition gradually recovered after discontinuation of TMS treatment and discharge from the hospital and, after 2 weeks, was more similar to pre-treatment composition than to composition during TMS treatment. Six months later, however, microbiota composition still differed significantly from that at the start of the study and Spirochaetes and Verrucomicrobia were less abundant. TMS administration led to a significant (up to 32-fold) and rapid increase in the relative abundance of resistance genes sul2, tetQ, ant6-1a, and aph(3")-lb. lnuC significantly decreased directly after treatment. Resistance genes sul2 (15-fold) and tetQ (six-fold) remained significantly increased 6 months later. CONCLUSIONS: Oral treatment with TMS has a rapid and long-lasting effect on faecal microbiota composition and resistome, making the equine hindgut a reservoir and potential source of resistant bacteria posing a risk to animal and human health through transmission. These findings support the judicious use of antimicrobials to minimise long-term faecal presence, excretion and the spread of antimicrobial resistance in the environment. Video Abstract.202336850017
1259160.8906Tetracycline resistance potential of heterotrophic bacteria isolated from freshwater fin-fish aquaculture system. AIMS: This study investigated the tetracycline resistance potential of heterotrophic bacteria isolated from twenty-four freshwater fin-fish culture ponds in Andhra Pradesh, India. METHODS AND RESULTS: A total of 261 tetracycline resistant bacteria (tetR) were recovered from pond water, pond sediment, fish gills, fish intestine, and fish feed. Bacteria with high tetracycline resistance (tetHR) (n = 30) that were resistant to tetracycline concentrations above 128  μg mL-1 were predominantly Lactococcus garvieae followed by Enterobacter spp., Lactococcus lactis, Enterobacter hormaechei, Staphylococcus arlettae, Streptococcus lutetiensis, Staphylococcus spp., Brevundimonas faecalis, Exiguobacterium profundum, Lysinibacillus spp., Stutzerimonas stutzeri, Enterobacter cloacae, and Lactococcus taiwanensis. Resistance to 1024 μg mL-1 of tetracycline was observed in L. garvieae, S. arlettae, Enterobacter spp., B. faecalis. Tet(A) (67%) was the predominant resistance gene in tetHR followed by tet(L), tet(S), tet(K), and tet(M). At similar concentrations of exposure, tetracycline procured at the farm level (69.5% potency) exhibited lower inhibition against tetHR bacteria compared to pure tetracycline (99% potency). The tetHR bacteria showed higher cross-resistance to furazolidone (100%) followed by co-trimoxazole (47.5%) and enrofloxacin (11%). CONCLUSIONS: The maximum threshold of tetracycline resistance at 1024 μg mL-1 was observed in S. arlettae, Enterobacter spp., B. faecalis, and L. garvieae and tet(A) was the major determinant found in this study.202336958862
2109170.8906Screening of nursing home residents for colonization with carbapenem-resistant Enterobacteriaceae admitted to acute care hospitals: Incidence and risk factors. BACKGROUND: There are increasing reports of multidrug-resistant gram-negative bacilli in nursing homes and acute care hospitals. METHODS: We performed a point prevalence survey to detect fecal carriage of gram-negative bacteria carrying carbapenem resistance genes or which were otherwise resistant to carbapenem antibiotics among 500 consecutive admissions from local nursing homes to 2 hospitals in Providence, Rhode Island. We performed a case-control study to identify risk factors associated with carriage of carbapenem-resistant Enterobacteriaceae (CRE). RESULTS: There were 404 patients with 500 hospital admissions during which they had rectal swab samples cultured. Fecal carriage of any carbapenem-resistant or carbapenemase- producing gram-negative bacteria was found in 23 (4.6%) of the 500 hospital admissions, including 7 CRE (1.4%), 2 (0.4%) of which were Klebsiella pneumoniae carbapenemase (ie, blaKPC) producing (CPE) Citrobacter freundii, 1 of which was carbapenem susceptible by standard testing methods. Use of a gastrostomy tube was associated with CRE carriage (P = .04). We demonstrated fecal carriage of carbapenem-resistant or carbapenemase-producing gram-negative bacteria in 4.6% of nursing home patients admitted to 2 acute care hospitals, but only 0.4% of such admissions were patients with fecal carriage of CPE. Use of gastrostomy tubes was associated with fecal carriage of gram-negative bacteria with detectable carbapenem resistance. CONCLUSION: CRE fecal carriage is uncommon in our hospital admissions from nursing homes.201626631643
2299180.8904Determining the resistance of carbapenem-resistant Klebsiella pneumoniae to common disinfectants and elucidating the underlying resistance mechanisms. INTRODUCTION: Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection is a serious problem in hospitals worldwide, posing a particular risk to immunocompromised patients. Elimination strategies may prevent these drug-resistant bacteria from spreading within hospital environments. Here, the susceptibility of patient-derived CRKP strains to common chemical disinfectants and possible correlations between the presence of drug-resistance genes and increased resistance to disinfectants were investigated. METHODS: The minimum inhibitory (MIC) and the minimum bactericidal concentrations (MBC) of common chemical disinfectants against each CRKP strain were determined using agar dilution; K. pneumoniae ATCC700603 served as a standard. The presence of the drug-resistance genes qacΔE, qacA, acrA and qacE was determined using PCR. RESULTS: A total of 27 clinically isolated CRKP strains collected in our hospital from 2011 to 2013 exhibited sensitivity to the following common chemical disinfectants in decreasing order of sensitivity: 75% ethyl alcohol > 2% glutaraldehyde > "84" disinfectant > 0.2% benzalkonium bromide > 2% iodine tincture > 1% iodophor > 0.1% chlorhexidine acetate. Of the 27 strains, 59, 41, 19 and 15% contained qacΔE, qacA, acrA and qacE resistance genes; 15% carried acrA, qacΔE and qacA, and 26% carried both qacA and qacΔE. Comparative analysis indicated that drug-resistance genes were correlated with higher MIC values. CONCLUSION: These pan-resistant pathogenic CRKP strains contained various drug-resistance genes and exhibited relatively high resistance to ethyl alcohol, chlorhexidine acetate and iodophor. Monitoring the drug-resistance rates of CRKP strains displaying disinfectant resistance may facilitate appropriate and effective sterilisation and thus preventing the spread of these pan-resistant strains.201526184804
2116190.8904Antibiotic 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