# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 1062 | 0 | 1.0000 | Prevalence of Biofilm-Forming, ESβLs and Metallo-β-lactamase Producing Gram-Negative MDR Bacteria in the Domestic and Hospital Wastewater of Aligarh City. Gram-negative pathogenic bacteria are a major contributor to antibiotic-resistant infections in hospitals and communities. The emergence of multidrug resistance (MDR) and biofilm formation complicates chemotherapy. This study aimed to assess the prevalence of multidrug-resistant (MDR) biofilm-forming, extended-spectrum beta-lactamase (ESβL) and metallo-beta-lactamase (MβL) producers in wastewater, which pose a public health threat. During 2022-2023, 117 enteric/Gram-negative isolates were isolated using selective culture techniques. Antimicrobial resistance was assessed via disc diffusion assay. ESβL and MβL production was confirmed through phenotypic and PCR-based methods. Biofilm formation was determined using a microtiter plate assay. Biofilms developed on glass coverslips were visualized by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Isolates with bla-(CTX-M), bla-(SHV), and bla-(NDM-1) genes were identified by partial 16S rRNA gene sequencing. A total of 93.16% of isolates were resistant to multiple drug classes (≥ 4), with the increased resistance to ampicillin (100%) and the lowest to gentamicin (12.82%). Biofilm assays indicated that 32.48% of MDR strains formed strong biofilms, 31.62% moderate, and 35.90% weak. β-lactamase activity appeared in 58.97% of isolates, with 56.41% confirmed as ESβL producers. PCR detection in ESβL-positive strains showed 84.61% carried CTX-M, 46.15% SHV, and 53.84% NDM-1 genes. 16S rRNA gene sequencing identified selected MDR strains as Escherichia coli (5), Klebsiella pneumoniae (1), Pseudomonas aeruginosa (1), Salmonella sp. (1), Enterobacter sp. (1), Citrobacter sp. (1), and Proteus sp. (1). The findings reveal the prevalence of biofilm-forming, ESβL, and MβL-producing Gram-negative pathogens in Aligarh's wastewater, underscoring the need for effective treatment to reduce public health risks from MDR bacteria and AMR genes. | 2025 | 40590993 |
| 1047 | 1 | 0.9999 | Biofilm formation and antibiotic resistance profiles of water-borne pathogens. Water sources (surface water, drinking water, rivers, and ponds) are significant reservoirs for transmitting antibiotic-resistant bacteria. In addition, these waters are an important public health problem because they are suitable environments for transferring antibiotic resistance genes between bacterial species. Our study aimed to assess the prevalence of Extended-spectrum beta-lactamase (ESBL) producing isolates in water samples, the susceptibility of the isolates to the specified antibiotics, the determination of biofilm ability, antibiotic resistance genes, and the molecular typing of the isolates. For this purpose, Polymerase chain reaction (PCR) and Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analyses were used. Out of 70 isolates, 15 (21%) were ESBL producing, and sent for the MALDI-TOF analysis, where Escherichia coli, Acinetobacter calcoaceticus, Enterobacter bugandensis, Acinetobacter pittii, Pseudomonas aeruginosa, Acinetobacter junii, Pseudomonas oleovorans, and Enterobacter ludwigigii were identified. Moreover, colistin resistance genes (mcr 1/2/6, mcr 4, mcr 5, mcr 3/7, and mcr 8), ESBL-encoding genes (bla(SHV), bla(TEM), and bla(CTX-M)) and carbapenemase genes (bla(NDM), bla(OXA-48), and bla(KPC)) using molecular analysis (PCR) were confirmed. The colistin resistance gene was detected at 80% (12/15) in the isolates obtained. The distribution of these isolates according to resistance genes was found as mcr 1/2/6 4 (20%), mcr 3/7 3 (13%), and mcr 5 (40%). Additionally, the isolates harbored bla(SHV)(6.6%) and bla(TEM) (6.6%) genes. However, bla(NDM), bla(OXA-48), bla(KPC), and bla(CTX-M) genes were not detected in any isolates. According to the Congo red agar method, seven (46.6%) isolates showed negative biofilm ability, and eight (53.3%) showed moderate biofilm ability. However, the microplate method detected weak biofilm in 53.3% of the isolates. In conclusion, this study provides evidence for the existence of multidrug-resistant bacteria that co-exist with mcr and ESBL genes in water sources. These bacteria can migrate to other environments and pose increasing threats to public health. | 2023 | 37004897 |
| 1061 | 2 | 0.9998 | Genotypic characterization of bacterial isolates causing urinary tract infections among adults at Kiambu Level 5 Hospital, Kenya: selected extended-spectrum β-lactamase genes and biofilm formation. The menace of antimicrobial resistance affecting public health is rising globally. Many pathogenic bacteria use mechanisms such as mutations and biofilm formation, significantly reducing the efficacy of antimicrobial agents. In this cross-sectional study, we aimed to determine the prevalence of selected extended-spectrum β-lactamase (ESβL) genes and analyse the biofilm formation abilities of the isolated bacteria causing urinary tract infection among adult patients seeking Medicare at Kiambu Level 5 Hospital, Kenya. The double-disc synergy test was used for phenotypic identification of ESβL-producing isolates, while microtitre plate assays with some modifications were used for the biofilm formation test. Ten isolates were bioassayed for ESβL genes out of 57 bacterial isolates obtained from urine samples. This study found the bla (TEM) genes to be the most prevalent ESβL type [10/10 (100 %)], followed by bla(OXA) and bla(SHV) genes at 4/10 (40 %) and 3/10 (30 %), respectively. In addition, co-carriage of bla(TEM) and bla(SHV) was 50 % lower than that of bla(TEM)+bla (OXA) genes at 66.7 % among Escherichia coli isolates studied. Biofilm formation was positive in 36/57 (63.2 %) of the isolates tested, with most being Gram-negative [25/36 (69.4 %)]. Escherichia coli [15/36 (41.7 %)], Klebsiella species [7/36 (19.4 %)] and Staphylococcus aureus [7/36 (19.4 %)] were the dominant biofilm formers. However, there was no significant difference in biofilm formation among all tested isolates, with all isolates recording P-values >0.05. In light of these findings, biofilm formation potential coupled with antimicrobial resistance genes in urinary tract infection isolates may lead to difficult-to-treat infections. | 2024 | 38482364 |
| 923 | 3 | 0.9998 | Prevalence of Oxacillinase Genes in Clinical Multidrug-Resistant Gram-Negative Bacteria. BACKGROUND: The emergence of OXA-type beta-lactamases has become a significant threat to public healthcare systems and may lead to prolonged hospital stays and increased mortality rates among affected patients. This study aimed to determine the prevalence of oxacillinase resistance (OXA) genes in multidrug-resistant (MDR) Gram-negative bacteria. METHODS: One hundred and six clinical isolates were collected from a stock of Gram-negative isolates and were identified and tested for antibiotic susceptibility and presence of OXA genes using polymerase chain reaction (PCR). RESULTS: The most common detected isolate was Klebsiella pneumoniae (36.8%), followed by Escherichia coli (33%), Pseudomonas aeruginosa (16%), and Acinetobacter baumannii (14.2%). Out of these isolates, 97.4%, 87.2%, 84.6%, and 79.5% were resistant to ampicillin/sulbactam, cefotaxime, ceftazidime, and aztreonam, respectively. PCR results confirmed the presence of one or more OXA genes in 34% of the samples studied. The blaOXA-1 and blaOXA-10 genes were the most highly detected genes, followed by blaOXA-4 and blaOXA-51. The total number of Pseudomonas aeruginosa isolates was confirmed to carry at least one OXA gene (70.6%), whereas Acinetobacter baumannii, Klebsiella pneumoniae, and Escherichia coli were confirmed to carry at least one OXA gene (53.3, 28.2, and 22.9%, respectively). There was a significant association (p < 0.05) between the resistance genes and the type of isolate. CONCLUSIONS: Pseudomonas aeruginosa and Acinetobacter baumannii are the most common MDR Gram-negative strains carrying OXA-type beta-lactamase genes. Monitoring of MDR pathogens in Gram-negative bacteria must be continuously undertaken to implement effective measures for infection control and prevention. | 2025 | 40066541 |
| 1050 | 4 | 0.9998 | Antibiotic resistance and β-lactam resistant genes among bacterial isolates from clinical, river water and poultry samples from Kathmandu, Nepal. OBJECTIVE: To assess the antibiotic resistance and beta-lactam resistance genes among bacterial isolates from clinical, river water and poultry samples. METHODS: Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were isolated from clinical, poultry and river water samples collected during 2020-22. They were subjected to antimicrobial susceptibility tests following the CLSI guidelines. The bacteria were screened for β-lactam resistance genes bla (TEM), mcr-1, mecA and bla(NDM-1) . RESULTS: Among 2835 clinical samples, E. coli was the most frequently isolated bacterium (10.3%, 292), followed by S. aureus (6.0%, 169) and P. aeruginosa (4.0%, 143). Of the E. coli isolates, 64.4% exhibited multidrug resistance (MDR) and 43.8% were extended-spectrum β-lactamase (ESBL) producers, with 44.5% and 16.4% harbouring the blaTEM and mcr-1 genes, respectively. Among S. aureus isolates, 80.9% of methicillin-resistant strains (MRSA) carried the mecA gene, while 30.1% of metallo-β-lactamase (MBL)-producing P. aeruginosa were positive for the blaNDM-1 gene. In poultry samples, 30.4% of E. coli isolates harboured the blaTEM gene among 128 ESBL producers, and the prevalence of colistin-resistant isolates carrying mcr-1 was higher than in clinical samples. In contrast, the occurrence of ESBL-producing E. coli and MRSA, along with their associated resistance genes, was lower in water samples. CONCLUSIONS: This study demonstrated widespread multidrug resistance (MDR) and ESBL production among clinical, poultry and river water bacterial isolates in the Kathmandu valley. Colistin-resistant E. coli carrying the mcr-1 gene, methicillin-resistant S. aureus (MRSA) with mecA and metallo-β-lactamase (MBL)-producing P. aeruginosa harboring blaNDM-1 were detected across sources. These findings emphasize an urgent One Health approach to curb the growing threat of antimicrobial resistance in the region. | 2025 | 41113068 |
| 1051 | 5 | 0.9998 | Multi-drug Resistance, β-Lactamases Production, and Coexistence of bla (NDM-1) and mcr-1 in Escherichia coli Clinical Isolates From a Referral Hospital in Kathmandu, Nepal. The ability of pathogenic Escherichia coli to produce carbapenemase enzymes is a characteristic that allows them to resist various antibiotics, including last-resort antibiotics like colistin and carbapenem. Our objectives were to identify rapidly developing antibiotic resistance (AR), assess β-lactamases production, and detect mcr-1 and bla (NDM-1) genes in the isolates. A prospective cross-sectional study was carried out in a referral hospital located in Kathmandu from November 2019 to December 2020 using standard laboratory and molecular protocols. Among 77 total E. coli isolates, 64 (83.1%) of them were categorized as MDR. Phenotypically 13 (20.3%) colistin-resistant, 30 (46.9%) ESBL and 8 (12.5%) AmpC producers, and 5 (7.8%) ESBL/AmpC co-producers were distributed among MDR-E. coli. Minimum inhibitory concentrations (MIC) against the majority of MDR isolates were exhibited at 1 g/L. Of these 77 E. coli isolates, 24 (31.2%) were carbapenem-resistant. Among these carbapenem-resistant bacteria, 11 (45.9%) isolates were reported to be colistin-resistant, while 15 (62.5%) and 2 (8.3%) were MBL and KPC producers, respectively. Out of 15 MBL producers, 6 (40%) harbored bla (NDM-1), and 8 (61.5%) out of 13 colistin-resistant pathogens possessed mcr-1. The resistance by colistin- and carbapenem were statistically associated (P < .001). However, only 2 (18.2%) of the co-resistant bacteria were found to have both genes. Our study revealed the highly prevalent MDR and the carbapenem-resistant E. coli and emphasized that the pathogens possess a wide range of capabilities to synthesize β-lactamases. These findings could assist to expand the understanding of AR in terms of enzyme production. | 2023 | 36741474 |
| 1052 | 6 | 0.9998 | Extended-spectrum beta-lactamase-producing Pseudomonas aeruginosa in camel in Egypt: potential human hazard. BACKGROUND: The rapid increase of extended-spectrum beta-lactamase (ESBL) producing bacteria are a potential health hazard. Development of antimicrobial resistance in animal pathogens has serious implications for human health, especially when such strains could be transmitted to human. In this study, the antimicrobial resistance due to ESBL producing Pseudomonas aeruginosa in the camel meat was investigated. METHODS: In this study meat samples from 200 healthy camels at two major abattoirs in Egypt (Cairo and Giza) were collected. Following culture on cetrimide agar, suspected P. aeruginosa colonies were confirmed with a Vitek 2 system (bioMe´rieux). P. aeruginosa isolates were phenotypically identified as ESBL by double disk synergy test. Additionally antimicrobial susceptibility testing of ESBL producing P. aeruginosa isolates were done against 11 antimicrobial drugs and carried out by disk diffusion method. The ESBL genotypes were determined by polymerase chain reaction according to the presence of the bla (PER-1), bla (CTX-M), bla (SHV), and bla (TEM). RESULTS: Pseudomonas aeruginosa was isolated from 45 camel meat sample (22.5%). The total percentage of ESBL producing P. aeruginosa was 45% (21/45) from camel meat isolates. Antibiogram results revealed the highest resistance was for c, ceftriaxone and rifampicin followed by cefepime and aztreonam. The prevalence rates of β-lactamase genes were recorded (bla (PER-1) 28.5%, bla (CTX-M) 38%, bla (SHV) 33.3% and bla (TEM) 23.8%). CONCLUSIONS: This study illustrates the presence of high rates of ESBL-P. aeruginosa in camels that represents an increasing alarming for the risk of transmission to human and opens the door for current and future antibiotics therapy failure. Livestock associated ESBL-P. aeruginosa is a growing disaster, therefore, attention has to be fully given to livestock associated ESBL-bacteria which try to find its way to human beings. | 2017 | 28359312 |
| 1038 | 7 | 0.9998 | Isolation of Extended Spectrum β-lactamase (ESBL) Producing Bacteria from Urban Surface Waters in Malaysia. BACKGROUND: This was a preliminary study to test for the presence of multiple antibiotic-resistant extended spectrum β-lactamase (ESBL) producing bacteria in Malaysian urban surface waters. Although the literature review revealed several published papers on clinical ESBL isolates in Malaysia, none were found on ESBL isolates obtained from local surface waters. METHODS: Isolated bacterial species were tested for resistance to cefotaxime, amoxicillin/clavulanate and aztreonam, and susceptibility to imipenem and meropenem using antibiotic susceptibility testing (AST) by disc diffusion. This served as a screening step to detect bacteria that could be potential ESBL species. 16S ribose ribonucleic acid (rRNA) polymerase chain reaction (PCR) testing with two clusters of bla (β-lactamase) gene primers was used to test for the bla genes CTX-M (Groups 1, 2, 9), OXA-1, SHV and TEM. RESULTS: A total of 19 isolates were found, possessing at least one of the bla genes tested for. There was a relatively high occurrence of CTX-M genes (84.2%) among these, followed by TEM genes (47.4%). The isolates were identified as Enterobacteriaceae (89.5%), predominantly Escherichia coli and Klebsiella pneumoniae. CONCLUSION: There appears to be a high occurrence of ESBL-bacteria in local surface waters, among these being opportunistic pathogens. The persistence and spread of these species in the environment poses a threat to exposed human populations. | 2013 | 23966820 |
| 955 | 8 | 0.9998 | Occurrence and characteristics of extended-spectrum β-lactamase- and carbapenemase- producing bacteria from hospital effluents in Singapore. One of the most important resistance mechanisms in Gram-negative bacteria today is the production of enzymes causing resistance to cephalosporin and carbapenem antibiotics. The spread of extended-spectrum β-lactamases (ESBL)- and carbapenemase- producing Gram-negative bacteria is an emerging global public health problem. The aim of the present study was to (i) assess the prevalence of carbapenem-resistant bacteria (CRB) and ESBL-producing strains in sewage effluents from two major hospitals in Singapore, (ii) characterize the isolated strains and (iii) identify some of the ESBL and carbapenemase genes responsible for the resistance. CHROMagar ESBL and KPC plates were used to rapidly screen for ESBL-producing bacteria and those expressing reduced susceptibility to carbapenems, respectively. The abundance of ESBL-producers and CRB in hospital wastewater ranged between 10(3) and 10(6)CFU/mL. Out of the 66 isolates picked from ESBL and KPC plates, 95%, 82%, 82% and 76% were resistant to ceftriaxone, ceftazidime (3rd generation cephalosporin family), ertapenem and meropenem (carbapenem family), respectively. Among the resistant isolates, the most predominant taxa identified were Pseudomonas spp. (28.2%), Klebsiella spp. (28.2%), Enterobacter spp. (18.3%) and Citrobacter spp. (11.3%). PCR and sequencing analysis showed that the predominant β-lactamase genes were bla(SHV) (41.1%) followed by bla(NDM-1) (35.6%), bla(CTX) (35.6%) and bla(KPC) (28.8%). The results of this study show a high prevalence of bacteria resistant to modern extended-spectrum cephalosporins and carbapenems and the presence of ESBL- and carbapenemase producers in hospital effluents. These findings support the need to improve management of hospital wastewater in order to minimize the spread of antimicrobial resistant microorganisms from this source. | 2018 | 29751417 |
| 1053 | 9 | 0.9998 | Antimicrobial Resistance and Extended-Spectrum Beta-Lactamase Genes in Enterobacterales, Pseudomonas and Acinetobacter Isolates from the Uterus of Healthy Mares. Antibiotic-resistant bacteria are a growing concern for human and animal health. The objective of this study was to determine the antimicrobial resistance and extended-spectrum beta-lactamase genes in Enterobacterales, Pseudomonas spp. and Acinetobacter spp. isolates from the uterus of healthy mares. For this purpose, 21 mares were swabbed for samples, which were later seeded on blood agar and MacConkey agar. The isolates were identified using MALDI-TOF and the antimicrobial susceptibility test was performed using the Kirby-Bauer technique. To characterize the resistance genes, a polymerase chain reaction (PCR) scheme was performed. Of the isolates identified as Gram-negative, 68.8% were Enterobacterales, represented by E. coli, Enterobacter cloacae, Citrobacter spp., and Klebsiella pneumoniae; 28.1% belonged to the genus Acinetobacter spp.; and 3.1% to Pseudomonas aeruginosa. A 9.3% of the isolates were multidrug-resistant (MDR), presenting resistance to antibiotics from three different classes, while 18.8% presented resistance to two or more classes of different antibiotics. The diversity of three genes that code for ESBL (bla(TEM), bla(CTX-M) and bla(SHV)) was detected in 12.5% of the strains. The most frequent was bla(SHV), while bla(TEM) and bla(CTX-M) were present in Citrobacter spp. and Klebsiella pneumoniae. These results are an alarm call for veterinarians and their environment and suggest taking measures to prevent the spread of these microorganisms. | 2023 | 37764953 |
| 1446 | 10 | 0.9998 | One-Day Prevalence of Extended-Spectrum β-Lactamase (ESBL) and Carbapenemase-Producing Bacteria in Fecal Samples from Surgical Patients: A Concerning Trend of Antibiotic Resistance. PURPOSE: Extended-spectrum β-lactamase (ESBL) and carbapenemase producing bacteria are of increasing concern due to their multidrug resistance and infection potential. This study determines the one-day prevalence of faecal carriage of ESBL and carbapenemase producing Gram-negative bacilli. METHODS: Fecal samples were collected from 30 post-surgery patients (hospitalized for at least 48 hours) in each of the four hospitals involved in the study and were analyzed for antibiotic-resistant bacteria. Identification was done using Maldi Tof mass spectrometry, and antibiotic susceptibility was tested using disk diffusion and specialized tests for ESBL (double disk synergy technique) and carbapenem (NG-TEST CARBA 5) resistance detection. PCR was conducted on isolates to detect betalactam resistance genes, carbapenemase genes and quinolone resistance genes. FINDINGS: Out of the 120 patients enrolled, 38.33% (n = 46) and 49.16.33% (n = 59) were found to carry ESBL- and carbapenemase-producing bacteria, respectively, in their fecal samples. Among the isolates, 51.08% (n = 47) exhibited ESBL production, with Escherichia coli (44.56%) being the most common species. The identification of bacteria with resistance to carbapenems showed a predominance of the species Escherichia coli (44.45%) followed by the species Klebsiella pneumoniae (16.06%) and Acinetobacter baumanii (13.58%). The study of the association of variables shows a high degree of association (p < 0.05) for the factors independent walking and use of a wheelchair with ESBL production. The most frequently detected genes among ESBL producing bacteria were bla(CTXM-1) (91.49%), qnrB (70.21%) and qnrs (63.82%). bla(NDM) (54.68%) was the most detected carbapenemase genes among carbapenemase producing isolates. CONCLUSION: This study demonstrates, for the first time, a significant prevalence of ESBL and carbapenemase producing gram-negative bacteria among surgical patients in Benin, with multiple resistance genes detected. Findings should be interpreted in light of the cross-sectional design and >48-hour hospitalization criterion. | 2025 | 40635768 |
| 1445 | 11 | 0.9998 | Rapid Detection of Beta-Lactamases Genes among Enterobacterales in Urine Samples by Using Real-Time PCR. The objective of this study was to develop and evaluate newly improved, rapid, and reliable strategies based on real-time PCR to detect the most frequent beta-lactamase genes recorded in clinical Enterobacterales strains, particularly in Tunisia (bla(SHV12) , bla(TEM) , bla(CTX-M-15) , bla(CTX-M-9) , bla(CMY-2) , bla(OXA-48) , bla(NDM-1) , and bla(IMP) ) directly from the urine. Following the design of primers for a specific gene pool and their validation, a series of real-time PCR reactions were performed to detect these genes in 78 urine samples showing high antibiotic resistance after culture and susceptibility testing. Assays were applied to DNA extracted from cultured bacteria and collected urine. qPCR results were compared for phenotypic sensitivity. qPCR results were similar regardless of whether cultures or urine were collected, with 100% sensitivity and specificity. Out of 78 multiresistant uropathogenic, strains of Enterobacterales (44 E. coli and 34 K. pneumoniae strains) show the presence of the genes of the bla group. In all, 44% E. coli and 36 of K. pneumoniae clinical strains harbored the bla group genes with 36.4%, 52.3%, 70.5%, 68.2%, 18.2%, and 4.5% of E. coli having bla(SHV-12) , bla(TEM) , bla(CTX-M 15) , bla(CTX-M-9) , bla(CMY-2) , and bla(OXA-48) group genes, respectively, whereas 52.9%, 67.6%, 76.5%, 35.5%, 61.8, 14.7, and 1.28% of K. pneumoniae had bla(SHV-12) , bla(TEM) , bla(CTX-M 15) , bla(CTX-M-9) , bla(CMY-2) , bla(OXA-48) , and bla(NDM-1) group genes, respectively. The time required to have a result was 3 hours by real-time PCR and 2 to 3 days by the conventional method. Resistance genes of Gram-negative bacteria in urine, as well as cultured bacteria, were rapidly detected using qPCR techniques. These techniques will be used as rapid and cost-effective methods in the laboratory. Therefore, this test could be a good candidate to create real-time PCR kits for the detection of resistance genes directly from urine in clinical or epidemiological settings. | 2022 | 35978630 |
| 1048 | 12 | 0.9998 | Characterizing the co-existence of metallo-β-lactamase-producing and extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolates in community wastewater samples of Dhaka, Bangladesh. Escherichia coli and Klebsiella pneumoniae isolates with multiple antibiotic-resistance genes in wastewater pose serious public health risks, as they can potentially contaminate the food and water supply. The main aim of this study was to isolate and identify E. coli and K. pneumoniae from community wastewater samples, and determine their antibiotic-resistance profiles and their antibiotic-resistant genes. From the northern part of Dhaka, Bangladesh, 36 wastewater samples were collected across 11 different areas, which were then serially diluted, and cultured using selective media. Isolates were identified via polymerase chain reaction. Out of the 197 isolates identified, E. coli and K. pneumoniae accounted for 55.8% (n = 110) and 44.2% (n = 87), respectively. Antibiotic susceptibility tests revealed multidrug resistance (MDR) in 30% of E. coli and 35.56% of K. pneumoniae isolates. Among E. coli, the prevalence of antibiotic-resistance genes included bla(NDM-1) (8.9%), bla(SHV) (13.9%), and bla(CTX-M) (7.6%). In K. pneumoniae, the percentages were bla(NDM-1) (12.8%), bla(SHV) (4.3%), and bla(CTX-M) (5.0%). Co-existence of multiple antibiotic-resistance genes was observed in 4.54% of E. coli isolates (n = 5) and 5.74% of K. pneumoniae isolates (n = 5). This suggests the escalating issue of infectious species becoming increasingly resistant to antibiotics in wastewater systems. | 2025 | 40298266 |
| 945 | 13 | 0.9998 | Extended Spectrum Beta Lactamase (ESBL), bla(TEM),bla(SHV) and bla(CTX-M), Resistance Genes in Community and Healthcare Associated Gram Negative Bacteria from Osun State, Nigeria. BACKGROUND: Extended Spectrum Beta Lactamase (ESBL) production in gram negative bacteria confers multiple antibiotic resistance, adversely affecting antimicrobial therapy in infected individuals. ESBLs result from mutations in β-lactamases encoded mainly by the bla(TEM),bla(SHV) and bla(CTX-M) genes. The prevalence of ESBL producing bacteria has been on the increase globally, especially its upsurge among isolates from community-acquired infections has been observed. AIM: To determine ESBL prevalence and identify ESBL genes among clinical isolates in Osun State, Nigeria. MATERIAL AND METHODS: A cross-sectional study was carried out from August 2016 - July 2017 in Osun State, Nigeria. Three hundred and sixty Gram-negative bacteria recovered from clinical samples obtained from both community and healthcare-associated infections were tested. They included 147 Escherichia coli (40.8%), 116 Klebsiella spp (32.2%), 44 Pseudomonas aeruginosa (12.2%) and 23 Proteus vulgaris (6.4%) isolates. Others were Acinetobacter baumannii, Serratia rubidae, Citrobacter spp, Enterobacter spp and Salmonella typhi. Disk diffusion antibiotic susceptibility testing was carried out, isolates were screened for ESBL production and confirmed using standard laboratory procedures. ESBLs resistance genes were identified by Polymerase Chain Reaction (PCR). RESULTS: All isolates demonstrated multiple antibiotic resistance. Resistance to ampicillin, amoxicillin with clavulanate and erythromycin was 100%, whereas resistance to Imipenem was very low (5.0%). The overall prevalence of ESBL producers was 41.4% with Klebsiella spp as the highest ESBL producing Enterobacteriacaea. ESBL producers were more prevalent among the hospital pathogens than community pathogens, 58% vs. 29.5% (p=0.003). ESBL genes were detected in all ESBL producers with the bla(CTX-M) gene predominating (47.0%) followed by bla(TEM) (30.9%) and bla(SHV) gene was the least, 22.1%. The bla(CTX-M) gene was also the most prevalent in the healthcare pathogens (62%) but it accounted for only 25% in those of community origin. CONCLUSION: A high prevalence of ESBL producing gram-negative organisms occurs both in healthcare and in the community in our environment with the CTX-M variant predominating. Efforts to control the spread of these pathogens should be addressed. | 2021 | 32729432 |
| 924 | 14 | 0.9998 | Screening of Antimicrobial Resistance Genes and Epidemiological Features in Hospital and Community-Associated Carbapenem-Resistant Pseudomonas aeruginosa Infections. INTRODUCTION: Researching carbapenem-resistant isolates enables the identification of carbapenemase-producing bacteria and prevents their spread. METHODS: P. aeruginosa isolates were recovered from Medicine Faculty of Recep Tayyip Erdoğan University and identified by conventional methods and the automated Vitek 2 Compact system. Antimicrobial susceptibility experiments were performed in accordance with CLSI criteria and the automated Vitek 2 Compact system. The PCR method was investigated for the presence of β-lactamase resistance genes. PFGE typing was performed to show clonal relation among samples. RESULTS: Seventy P. aeruginosa isolates were isolated from seventy patients. Of the patients, 67.1% had contact with the health service in the last 90 days and 75.7% of the patients had received antimicrobial therapy in the previous 90 days. Twenty-four isolates were carbapenem resistant, 2 isolates were multidrug-resistant except colistin, and none of the samples had colistin resistance. The gene encoding β-lactamase or metallo-β-lactamase was found in a total of 36 isolates. The bla (VEB) and bla (PER) genes were identified in 1 and 5 isolates alone or 17 and 13 isolates in combination with other resistance genes, respectively. The bla (NDM) was the most detected metallo-β-lactamase encoding gene (n=18), followed by bla (KPC) (n=12). bla (IMP) and bla (VIM) were detected in 5 and 1 isolates, respectively. Also, the association of bla (VEB)-bla (PER) and bla (VEB)-bla (KPC)-bla (NDM) was found to be very high. Much more resistance genes and co-occurrence were detected in hospital-acquired samples than community-acquired samples. No difference was found between the community and hospital-associated isolates according to PFGE results. Simultaneously from 6 patients, other microorganisms were also isolated and 5 of them died. CONCLUSION: The average length of stay (days) was found to be significantly higher in HAI group than CAI group. The death of 5 patients with fewer or no resistance genes showed that the co-existence of other microorganisms in addition to resistance genes was important on death. | 2021 | 33907430 |
| 980 | 15 | 0.9998 | Phenotypic and Molecular Characterization of Extended-Spectrum β-Lactamase, Plasmid-Mediated- AmpC, and Carbapenemase-Producing Enterobacteriaceae Isolated from Companion and Production Animals in Brazil. The crisis of bacterial resistance is an emerging One Health challenge, driven by the overuse of antimicrobials in medical and agricultural settings. This study aimed to investigate extended-spectrum β-lactamase (ESBL), Ampicillinase (AmpC), and carbapenemase production, and the presence of genes encoding these enzymes in Escherichia coli, Klebsiella spp., and Proteus spp., major contributors to infections and resistance isolates from animals. From 2016 to 2021, 130 multidrug-resistant (MDR) or extensively drug-resistant (XDR) isolates were recovered from the secretions, excretions, and organs of companion and production animals with active infections. Antibacterial sensitivity tests, along with phenotypic and genotypic detection of resistance enzymes, were performed. To the best of our knowledge, this is the first study in Brazil to estimate the prevalence of XDR Enterobacteriales isolated from companion and production animals, which accounted for 13.8% of the strains. Statistically significant differences (P < 0.05) in resistant bacteria between different classes and within the same class of antibacterial bacteria were found. The statistical probability between genotypic detection of ESBL (OR = 3.1) and phenotypic tests for AmpC (OR = 2.3) was also established. Approximately 32.3%, 17.6%, and 16.8% of the strains had positive phenotypic tests for ESBL, AmpC, and carbapenemases, respectively. Genetic analysis revealed the presence of bla(CTX-M) (60.0%), bla(AmpC) (9.18%), bla(KPC-2) (0.76%), and bla(NDM) (1.52%). AmpC genes were identified in 8.46% of the samples, with bla(CMY) being the most frequent (6.92%), followed by bla(DHA) (0.77%), and bla(FOX) (0.77%). The sequenced amplicons were deposited in NCBI. This study reveals critical data on Enterobacteriaceae with antibacterial resistance genes isolated from animals and may pose a significant threat to One health. | 2025 | 39903315 |
| 1016 | 16 | 0.9998 | Investigation of CTX-M Type Extended-Spectrum β-Lactamase, Carbapenem and Colistin Resistance in Enterobacterales Isolated From Dairy Cattle in Turkey. BACKGROUND: The increasing prevalence of antimicrobial resistance in animals, particularly the spread of multidrug-resistant Enterobacterales, poses a significant zoonotic and public health risk. OBJECTIVE: The aim of this study was to investigate extended-spectrum β-lactamase (ESBL), carbapenem and colistin resistance among Enterobacterales in faecal swabs of dairy cattle. METHODS: A total of 400 samples were cultured on Mac Conkey screening media for ESBL, carbapenem and colistin resistance. The grown Enterobacterales were identified by MALDI-TOF-MS, followed by ceftriaxone, cefotaxime and ceftazidime resistance and double disk synergy. ESBL resistance genes were identified by polymerase chain reaction (PCR) and Sanger sequencing. Bacteria grown on colistin screening media were investigated for colistin resistance by EUCAST microbroth dilution method. RESULTS: A total of 89 (22.25%) of the bacteria grown from 400 samples were identified as potential ESBL-producing Enterobacterales members. A number of 53 (59.5%) of them were identified as ESBL blaCTX-M as a result of PCR, and 10 of them were identified as blaCTX-M-15/28/36/66 as a result of sequencing. None of the samples cultured on carbapenem medium grew. A total of 18 samples grown in colistin medium were found to be colistin sensitive by broth microdilution. Genotypes were not included in the study. All isolated bacteria were identified as Escherichia coli. SOLUTION: In this study, blaCTX-M-15 and its derivatives, which are common in humans, were also found to be the predominant ESBL type in animals. Monitoring resistance in animals together with resistance in human infections may provide more important data on the spread of resistance. | 2025 | 40704983 |
| 2111 | 17 | 0.9998 | Antimicrobial Resistance and Resistance Determinant Insights into Multi-Drug Resistant Gram-Negative Bacteria Isolates from Paediatric Patients in China. INTRODUCTION: The emergence of multi-drug-resistant Gram-negative bacteria (GNB) is a concern in China and globally. This study investigated antimicrobial resistance traits and resistance determinant detection in GNB isolates from paediatric patients in China. METHODS: In the present study, a total of 170 isolates of GNB including the most prevalent Escherichia coli, Klebsiella pneumoniae and Acinetobacter baumannii were collected from Shenzhen Children's Hospital, China. ESBLs production was confirmed by using the combination disc diffusion method, and carbapenemase production was confirmed by using a carbapenem inactivation method followed by antimicrobial susceptibility. In addition, β-lactamase-encoding genes and co-existence of plasmid-borne colistin resistance mcr-1 gene were determined by PCR and sequencing. RESULTS: Overall, 170 etiological agents (GNB) were recovered from 158 paediatric patients. The most prevalent species was E. coli 40% (n=68), followed by K. pneumoniae 17.64% (n=30), and Enterobacter cloacae 14.11% (n=24). Of 170 GNB, 71.76% (n=122) were multi-drug-resistant, 12.35% (n=21) extreme-drug resistant, and 7.64% (n=13) single-drug-resistant, while 8.23% (n=14) were sensitive to all of the studied antibiotics. The prevalence of ESBLs and carbapenemase producers were 60% and 17%, respectively. bla (CTX-M) was the most prevalent resistance gene (59.42%), followed by bla (TEM) (41.17%), bla (SHV) (34.270%), bla (KPC) (34.11%), bla (OXA-48) (18.82%) and bla (NDM-1) (17.64%). CONCLUSION: The present study provides insights into the linkage between the resistance patterns of GNB to commonly used antibiotics and their uses in China. The findings are useful for understanding the genetics of resistance traits and difficulty in tackling of GNB in paediatric patients. | 2019 | 31819545 |
| 994 | 18 | 0.9998 | Moroccan Hospital Cockroaches: Carriers of Multidrug-Resistant Gram-Negative Bacteria. Antimicrobial resistance in Gram-negative bacteria (GNB) is a growing global health concern, particularly in hospital environments, where cockroaches act as vectors for resistant strains. This study aimed to analyze antimicrobial resistance and biofilm formation in GNB isolated from cockroaches collected in the hospital environment. Cockroaches were collected, and bacterial isolation was performed from their gut contents and external surfaces. GNB strains were tested for antibiotic susceptibility using the disk diffusion method and examined for Extended-spectrum β-lactamases (ESBLs) and carbapenemases production. Molecular characterization of ESBLs and carbapenemases in GNB involved PCR amplification of antibiotic resistance genes, while biofilm formation was studied using a microplate assay. Seventy-five cockroaches were collected from which 165 GNB were isolated. The prevalence of ESBL-producing and carbapenemase-producing GNB was 6.7 and 1.8%, respectively. The predominant ESBL gene was bla(CTX-M-28), while bla(NDM-1) was the only carbapenemase gene detected. The qnrS1 gene was found in one NDM-1-producing Klebsiella pneumoniae and three ESBL-producing Escherichia coli. The qacΔE1 gene was detected in an NDM-1-producing Citrobacter freundii and a CTX-M-28-producing E. coli, whereas one NDM-1-producing Enterobacter cloacae carried both qacΔE1 and acrA genes. Strains harboring qacΔE1 and/or acrA genes exhibited biofilm-forming capabilities, with biofilm formation observed in 81.81% of ESBL-producing isolates and 100% of carbapenemase-producing isolates. The study underscores the role of cockroaches in carrying and disseminating ESBL- and carbapenemase-producing GNB in hospital settings. The coexistence of disinfectant resistance genes and antibiotic resistance suggests co-selection mechanisms, while biofilm formation enhances bacterial survival. These findings underline the urgent need for infection control strategies. | 2025 | 40095169 |
| 949 | 19 | 0.9998 | Molecular 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. | 2024 | 39695444 |