Prevalence of Extended-Spectrum β-Lactamase-Producing Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae in Wastewater Effluent in Blantyre, Malawi. - Related Documents




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122001.0000Prevalence of Extended-Spectrum β-Lactamase-Producing Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae in Wastewater Effluent in Blantyre, Malawi. Background/Objectives: Wastewater treatment plants (WWTPs) serve as a sink for both antimicrobial residues and bacteria carrying resistant genes, which are later disseminated into the environment, facilitating the spread of antimicrobial resistance. This study investigated the presence of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (Ec), Klebsiella pneumoniae (Kp), and Enterobacter cloacae (Enc) in effluent from WWTP in Blantyre, Malawi, to generate evidence and provide baseline information for interventions. Methods: Selective chromogenic agar was used to identify ESBL-producing bacteria. Results: A total of 288 samples were collected between April 2023 and March 2024, and 97.6% (281/288) yielded one or more presumptive ESBL isolates. Bacterial growth was confirmed as 48.9% Ec (255/522), 33.0% Kp (172/522), and 10.0% Enc (52/522). Antibiotic susceptibility testing showed the highest resistance to ceftriaxone (Ec, 100.0%; Kp, 98.3%; Enc, 100.0%) and the lowest resistance to meropenem (Ec, 6.3%, Kp, 1.2%; Enc, 3.8%) among the antibiotics that were tested. Multiple antibiotic resistance phenotypes were observed in 73.1% of the isolates, with the most prevalent phenotype being amoxicillin + clavulanate/cotrimoxazole/doxycycline/ciprofloxacin/gentamicin/azithromycin/ceftriaxone (55, 15.7%). Conclusions: The study demonstrated ongoing environmental contamination with antibiotic-resistant bacteria from sewage effluent. Therefore, the functionality of WWTPs should be improved to minimize the release of these organisms into the environment.202540558152
121910.9995Characterization of extended-spectrum beta-lactamase and carbapenemase genes in bacteria from environment in Burkina Faso. INTRODUCTION: This study aimed to characterize extended-spectrum beta-lactamase (ESBL) and carbapenemase genes in bacteria from the environment in Bobo-Dioulasso, Burkina Faso. METHODOLOGY: This study was conducted from January 18 to December 31, 2019. Environmental samples were collected from the effluents of Souro Sanou University Hospital Center and the wastewater treatment plant at Bobo-Dioulasso. MacConkey agar media supplemented with 4 µg/mL cefotaxime was used for bacterial growth, and identification of bacteria was performed using API 20E system (BioMerieux SA, Lyon, France). Antibiotic susceptibility testing, synergy test, carbapenem inactivation method and molecular characterization were performed. RESULTS: A total of 180 bacterial isolates were identified from the different sites with a predominance of Klebsiella oxytoca and Klebsiella pneumoniae (27.5%). All 180 bacterial isolates were ESBL producers and 18 (10.0%) of them produced carbapenemases. Out of the 180 bacterial isolates, DNAs of 98.9% (178/180) bacterial isolates were extracted and tested through polymerase chain reaction (PCR) for characterization of resistant genes. The study showed that 89.8% (160/178) carried the bla-CTX-M genes including 54.4 (87/160) from hospital effluents and 45.6 (73/160) from the wastewater treatment plant. Regarding the carriage of carbapenemase genes, 7.9 (14/178) blaNDM-1 was found in all the sites including 71.4% (10/14) from hospital effluents and 28.6 (4/14) from the wastewater treatment plant. blaOXA-48-like was only found in bacteria from hospital effluents and represented 2.2% (4/178). CONCLUSIONS: This study highlights the need to build hospital effluent treatment plants to reduce the load of resistant bacteria before discharging the effluents into the urban wastewater system.202338252715
142120.9995Predominance of Acinetobacter spp., Harboring the bla(IMP) Gene, Contaminating the Hospital Environment in a Tertiary Hospital in Mwanza, Tanzania: A Cross-Sectional Laboratory-Based Study. Data on colonization and hospital contamination of carbapenem-resistant Gram-negative bacteria (CR-GNB) are limited in low- and middle-income countries. We designed this study to determine the prevalence and co-existence of carbapenemase genes among CR-GNB isolated from clinical, colonization, and hospital environmental samples at a tertiary hospital in Mwanza, Tanzania. The modified Hodge test (MHT), the combined disk test (CDT), and the double-disk synergy test (DDST) were used for the phenotypic detection of carbapenemases. A multiplex PCR assay was used to detect bla(IMP) and bla(KPC), and a singleplex PCR assay was used to detect bla(OXA-48). Data were analyzed by STATA version 13.0. Overall, 68.8% (44/64) of the CR-GNB had at least one phenotype by phenotypic methods, whereby 60.9% (39/64) were both CDT and DDST positive and 31.3% (20/64) were MHT positive. A total of 23/64 (35.9%) had at least one of the genes tested with the predominance of bla(IMP) (91.3%; 21/23). In addition, 47.7% (21/44) of the CR-GNB phenotypes had at least one gene. Around 47.8% (11/23) of the CR-GNB carried multiple genes encoding for carbapenem resistance, with the maximum co-existence of bla(IMP)/bla(KPC)/bla(OXA-48) (45.5%; 5/11). The majority of carbapenem-resistant genes were detected in Acinetobacter spp. (82.6%; 19/23) and isolated from bed swabs (69.6%; 16/23). Acinetobacter spp. carrying the bla(IMP) gene predominantly contaminated the hospital environment. Therefore, we recommend routine decontamination of inanimate hospital surfaces, including patient beds.202235056011
142030.9995Metallo-β-lactamase and AmpC genes in Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa isolates from abattoir and poultry origin in Nigeria. BACKGROUND: Gram-negative bacteria (GNB) including Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae represent the most relevant reservoir of resistance genes such as metallo-β-lactamase (MBL) and AmpC genes that give them the undue advantage to resist antimicrobial onslaught. This study aimed to investigate the occurrence of MBL (bla(IMP-1), bla(IMP-2), bla(VIM-1), bla(VIM-2)) and AmpC (bla(FOX), bla(DHA), bla(CMY), bla(ACC)) resistance genes in aforementioned GNB collected from abattoir and poultry sources in Nigeria. RESULTS: In total, 370 isolates were collected from abattoir tables (n = 130), anal region of cows (n = 120), and the cloacae of poultry birds (n = 120). The test isolates showed high rate of resistance to cephalosporins and carbapenems. The MBLs were phenotypically detected in 22 E. coli, 22 P. aeruginosa, and 18 K. pneumoniae isolates using combined disc test (CDT). However, only 11 E. coli, 24 P. aeruginosa, and 18 Klebsiella pneumoniae isolates were phenotypically confirmed to be AmpC producers using cefoxitin-cloxacillin double disk synergy test (CC-DDST). MBL encoding genes (particularly the bla(IMP-1) genes and bla(IMP-2) genes) were detected by polymerase chain reaction (PCR) in 12 (54.6%) E. coli, 15 (83.3%) K. pneumoniae, and 16 (72.7%) P. aeruginosa isolates. AmpC genes (particularly the bla(CMY) genes and bla(FOX) genes) were found in a total of 5 (29.4%) E. coli isolates, 5 (27.8%) isolates of K. pneumoniae, and 10 (41.7%) isolates of P. aeruginosa. CONCLUSIONS: Our study showed the circulation of MBL and AmpC genes in GNB from abattoir and poultry origin in Nigeria. Adoption of regular control policies is necessary to reduce the spread of these species as soon as possible, especially in poultry and slaughterhouses.202133882823
142240.9994Identification of bla(OXA-51-23-58), bla(VIM), bla(NDM), and bla(IMP) carbapenemase genes in Acinetobacter baumannii isolates from hospitalized patients. OBJECTIVE: The increase of multidrug-resistant (MDR) strains of Acinetobacter baumannii (A. baumannii), especially carbapenem-resistant strains, is challenging for treating infections. This study investigated the antibiotic resistance pattern and frequency of carbapenem resistance genes (oxacillinase and metallo-beta-lactamase) in A. baumannii. RESULTS: In this study, 100 bacterial isolates were collected from clinical samples from different hospitals in Isfahan, central of Iran. Of 100 samples of bloodstream, urine, cerebrospinal fluid (CSF), wound, and trachea, 60 bacteria were identified as A. baumannii. The results showed that 100% of the selected isolates were resistant to cefotaxime, ceftazidime, ciprofloxacin, piperacillin-tazobactam, and meropenem. Based on the antibiotic resistance pattern, 25 isolates were chosen for PCR analysis targeting bla(OXA-51), bla(OXA-23), bla(OXA-58), bla(NDM), bla(IMP), and bla(VIM) genes PCR results revealed that among the selected isolates, 15 (60.0%) harbored the bla(OXA-23) gene, 23 (92.0%) contained the bla(OXA-51) gene, and 1 (4.0%) isolate carried the bla(NDM) gene. Based on MLST analysis, two colistin-resistant Acinetobacter baumannii isolates were categorized as ST2. The ST2 clone represents the predominant sequence type within the CC2 or international clone two. The results showed that the best antibiotic against isolates was colistin. bla(OXA-51) and bla(OXA-23) genes (oxacillinase genes) were dominant genes, but bla(IMP) and bla(OXA-58) were not local carbapenem resistant genes in Isfahan.202439736661
94850.9994Multidrug-Resistant Bacteria in Aquaculture Systems in Accra, Ghana. BACKGROUND: Antibiotic resistance (ABR) poses a critical global health challenge, necessitating its surveillance across both human and animal health sectors. This study evaluated ABR in bacteria harboured in reared inland fishes sold in Accra and the pond water from which they originated. METHOD: The study was cross-sectional, involving fishes and water sampled from 80 ponds. The gastrointestinal organs of the fishes were homogenised and cultured for bacteria, as were the water samples. The bacteria were identified using matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI-TOF-MS). Antimicrobial susceptibility test was done using the Kirby-Bauer method. Multidrug-resistant (MDR) bacteria were selected for further testing. The double disc diffusion method was used to detect extended-spectrum beta-lactamase (ESBL) production in isolates that were resistant to third-generation cephalosporins. Whole genome sequencing was performed on the ESBL-positive isolates using the Illumina Miseq platform. RESULTS: In total, 39 different bacterial species, with their individual numbers totalling 391, were isolated. The bacteria were predominantly Escherichia coli (17%), Aeromonas veronii (11%), Citrobacter freundii (8%), Bacillus cereus (5%), and Klebsiella pneumoniae (5%). The overall ABR rates were cefotaxime (32%), gentamicin (1%), ciprofloxacin (4%), chloramphenicol (19%), tetracycline (37%), meropenem (0%), and ertapenem (0%). Overall MDR and ESBL bacteria prevalence were 13.6% and 1.3%, respectively. The sequence types of the ESBL isolates were ST4684 (80%, n = 4) and ST2005 (20%, n = 1), and the serotypes were H34:09 (80%, n = 4) and H7 (20%, n = 1); the ABR genes were blaCTX-M-15, fosA7, and qnrS1. CONCLUSION: The fishes and the pond water were contaminated with a diverse range of bacteria, mainly Escherichia coli and Aeromonas veronii. The ABR, MDR, and ESBL rates were low to moderate. Moreover, the main sequence type and serotype of the ESBL isolates were ST4684 and H34:09, respectively, and the ABR genes were blaCTX-M-15, fosA7, and qnrS1.202439600552
145660.9994Resistance and Co-Resistance of Metallo-Beta-Lactamase Genes in Diarrheal and Urinary-Tract Pathogens in Bangladesh. Carbapenems are the antibiotics of choice for treating multidrug-resistant bacterial infections. Metallo-β-lactamases (MBLs) are carbapenemases capable of hydrolyzing nearly all therapeutically available beta-lactam antibiotics. Consequently, this research assessed the distribution of two MBL genes and three β-lactamases and their associated phenotypic resistance in diarrheal and urinary-tract infections (UTIs) to guide future policies. Samples were collected through a cross-sectional study, and β-lactamase genes were detected via PCR. A total of 228 diarrheal bacteria were isolated from 240 samples. The most predominant pathogens were Escherichia coli (32%) and Klebsiella spp. (7%). Phenotypic resistance to amoxicillin-clavulanic acid, aztreonam, cefuroxime, cefixime, cefepime, imipenem, meropenem, gentamicin, netilmicin, and amikacin was 50.4%, 65.6%, 66.8%, 80.5%, 54.4%, 41.6%, 25.7%, 41.2%, 37.2%, and 42.9%, respectively. A total of 142 UTI pathogens were identified from 150 urine samples. Klebsiella spp. (39%) and Escherichia coli (24%) were the major pathogens isolated. Phenotypic resistance to amoxicillin-clavulanic acid, aztreonam, cefuroxime, cefixime, cefepime, imipenem, meropenem, gentamicin, netilmicin, and amikacin was 93.7%, 75.0%, 91.5%, 93.7%, 88.0%, 72.5%, 13.6%, 44.4%, 71.1%, and 43%, respectively. Twenty-four diarrheal isolates carried blaNDM-1 or blaVIM genes. The overall MBL gene prevalence was 10.5%. Thirty-six UTI pathogens carried either blaNDM-1 or blaVIM genes (25.4%). Seven isolates carried both blaNDM-1 and blaVIM genes. MBL genes were strongly associated with phenotypic carbapenem and other β-lactam antibiotic resistance. blaOXA imparted significantly higher phenotypic resistance to β-lactam antibiotics. Active surveillance and stewardship programs are urgently needed to reduce carbapenem resistance in Bangladesh.202439203431
112070.9994Occurrence of NDM-1 and VIM-2 Co-Producing Escherichia coli and OprD Alteration in Pseudomonas aeruginosa Isolated from Hospital Environment Samples in Northwestern Tunisia. Hospital environments constitute the main reservoir of multidrug-resistant bacteria. In this study we aimed to investigate the presence of Gram-negative bacteria in one Northwestern Tunisian hospital environment, and characterize the genes involved in bacterial resistance. A total of 152 environmental isolates were collected from various surfaces and isolated using MacConkey medium supplemented with cefotaxime or imipenem, with 81 fermenter bacteria (27 Escherichia coli, and 54 Enterobacter spp., including 46 Enterobacter cloacae), and 71 non-fermenting bacteria (69 Pseudomonas spp., including 54 Pseudomonas aeruginosa, and 2 Stenotrophomonas maltophilia) being identified by the MALDI-TOF-MS method. Antibiotic susceptibility testing was performed by disk diffusion method and E-Test was used to determine MICs for imipenem. Several genes implicated in beta-lactams resistance were characterized by PCR and sequencing. Carbapenem resistance was detected among 12 isolates; nine E. coli (bla(NDM-1) (n = 8); bla(NDM-1) + bla(VIM-2) (n = 1)) and three P. aeruginosa were carbapenem-resistant by loss of OprD porin. The whole-genome sequencing of P. aeruginosa 97H was determined using Illumina MiSeq sequencer, typed ST285, and harbored bla(OXA-494). Other genes were also detected, notably bla(TEM) (n = 23), bla(CTX-M-1) (n = 10) and bla(CTX-M-9) (n = 6). These new epidemiological data imposed new surveillance strategies and strict hygiene rules to decrease the spread of multidrug-resistant bacteria in this area.202134573959
94580.9994Extended 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.202132729432
112490.9994Molecular Identification of Extended-Spectrum β-lactamase and Integron Genes in Klebsiella Pneumonia. INTRODUCTION: Infections caused by Gram negative bacteria, producing extended-spectrum β-lactamase, including Klebsiella pneumoniae are increasing all over the world with high morbidity and mortality. The aim of the present study was determined antimicrobial profile susceptibility and the prevalence of antibiotic resistance genes by multiplex PCR. METHODS: In the present study, we obtained one-hundred isolates of K. pneumoniae from different clinical samples. The antibiotic susceptibility testing was done in thirteen antibiotic and, therefore, M-PCRs were conducted using the DNA amplification for detection of ESBLs (blaTEM, blaCTX-M, blaSHV) and int (I, II, III) genes. RESULTS: The results of resistance to amoxicillin/clavulanate, ciprofloxacin, amikacin, trimethoprim-sulfamethoxazole, cefotaxime, ampicillin, aztreonam, imipenem, gentamicin, ceftazidime, Cefepime, ceftriaxone and levofloxacin were obtained 37%, 37%, 93%, 84%, 52%, 87%, 59%, 8%, 24%, 67%, 52%, 43% and 26%, respectively. The frequency of the extended-spectrum β-lactamase K. pneumoniae was obtained 37%. The prevalence of resistance genes of ESBLs in the M-PCR method showed that the blaTEM, blaCTX and blaSHV were 38%, 24% and 19%, respectively, however, only 8 (8%) out of 100 isolates were found to have positive outcomes for the existence of class 1 integrons and there were no detected class 2 or class 3 integrons. CONCLUSIONS: Our results recommend the likely co-carriage of some ESBLs genes and antibiotic resistance integrons on the same plasmids harboring the MDR genes.201627935927
1446100.9994One-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.202540635768
1116110.9994Detection of blaCTX-M genes in ESBL-producing Klebsiella isolates from animals in Croatia. This study investigated the frequency of third-generation cephalosporin resistance in Klebsiella spp. isolated from animals in Croatia and the presence of blaCTX-M genes. A total of 711 enteric bacteria were isolated from clinical samples, and Klebsiella spp. isolates accounted for 6.9% (n = 49). Thirteen Klebsiella isolates (26.5%) were ESBL producers, nine isolates from the Klebsiella pneumoniae species complex (69.2%), and four (30.8%) Klebsiella oxytoca isolates. All carried the blaCTX-M-15 gene, and antimicrobial susceptibility testing revealed them as multidrug resistant. All were resistant to all tested cephalosporins, fluoroquinolones, aminoglycosides and aztreonam, 92.3% showed resistance to tetracycline, 84.6% to trimethoprim-sulfamethoxazole and 69.2% to nitrofurantoin. No isolate showed resistance to imipenem and meropenem. It can be concluded that ESBL-producing Klebsiella expressing the blaCTX-M gene are not rare among Klebsiella isolates from animals in Croatia.202337027245
1447120.9994Molecular detection of β-lactamase and integron genes in clinical strains of Klebsiella pneumoniae by multiplex polymerase chain reaction. INTRODUCTION: Infections caused by β-lactamase-producing gram-negative bacteria, such as Klebsiella pneumoniae, are increasing globally with high morbidity and mortality. The aim of the current study was to determine antimicrobial susceptibility patterns and the prevalence of antibiotic resistance genes (β-lactamase and integron genes) using multiplex PCR. METHODS: One-hundred K. pneumoniae isolates were collected from different clinical samples. Antibiotic susceptibility testing was performed with thirteen different antibiotics. Multiplex-PCR was used to detect β-lactamase (bla TEM, bla CTX-M, bla SHV , bla VEB, bla PER, bla GES, bla VIM, bla IMP, bla OXA, and bla KPC) and integron genes (int I, int II, and int III). RESULTS: The highest and lowest rate of resistance was exhibited against amikacin (93%) and imipenem (8%), respectively. The frequency of β-lactamase-positive K. pneumoniae was 37%, and the prevalence of the bla TEM, bla CTX-M, bla SHV , bla VEB, bla PER, bla GES, bla VIM, bla IMP, bla OXA, and bla KPC genes was 38%, 24%, 19%, 12%, 6%, 11%, 33%, 0%, 28%, and 23%, respectively. Of the 100 isolates, eight (8%) were positive for class I integrons; however, class II and III integrons were not detected in any of the strains. CONCLUSIONS: These results indicate co-carriage of a number of β-lactamase genes and antibiotic resistance integrons on the same plasmids harboring multi-drug resistance genes. It seems that these properties help to decrease treatment complications due to resistant bacterial infections by rapid detection, infection-control programs and prevention of transmission of drug resistance.201728700049
1048130.9993Characterizing 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.202540298266
1243140.9993Population distribution of Beta-lactamase conferring resistance to third-generation cephalosporins in human clinical Enterobacteriaceae in the Netherlands. There is a global increase in infections caused by Enterobacteriaceae with plasmid-borne β-lactamases that confer resistance to third-generation cephalosporins. The epidemiology of these bacteria is not well understood, and was, therefore, investigated in a selection of 636 clinical Enterobacteriaceae with a minimal inhibitory concentration >1 mg/L for ceftazidime/ceftriaxone from a national survey (75% E. coli, 11% E. cloacae, 11% K. pneumoniae, 2% K. oxytoca, 2% P. mirabilis). Isolates were investigated for extended-spectrum β-lactamases (ESBLs) and ampC genes using microarray, PCR, gene sequencing and molecular straintyping (Diversilab and multi-locus sequence typing (MLST)). ESBL genes were demonstrated in 512 isolates (81%); of which 446 (87%) belonged to the CTX-M family. Among 314 randomly selected and sequenced isolates, bla(CTX-M-15) was most prevalent (n = 124, 39%), followed by bla(CTX-M-1) (n = 47, 15%), bla(CTX-M-14) (n = 15, 5%), bla(SHV-12) (n = 24, 8%) and bla(TEM-52) (n = 13, 4%). Among 181 isolates with MIC ≥16 mg/L for cefoxitin plasmid encoded AmpCs were detected in 32 and 27 were of the CMY-2 group. Among 102 E. coli isolates with MIC ≥16 mg/L for cefoxitin ampC promoter mutations were identified in 29 (28%). Based on Diversilab genotyping of 608 isolates (similarity cut-off >98%) discriminatory indices of bacteria with ESBL and/or ampC genes were 0.994, 0.985 and 0.994 for E. coli, K. pneumoniae and E. cloacae, respectively. Based on similarity cut-off >95% two large clusters of E. coli were apparent (of 43 and 30 isolates) and 21 of 21 that were typed by belonged to ST131 of which 13 contained bla(CTX-M-15). Our findings demonstrate that bla(CTX-M-15) is the most prevalent ESBL and we report a larger than previously reported prevalence of ampC genes among Enterobacteriaceae responsible for resistance to third-generation cephalosporins.201223284886
1122150.9993Antibiotic resistance profiles of gram-negative bacteria in southern Tunisia: Focus on ESBL, carbapenem and colistin resistance. The main objective of this cross-sectional study was to investigate the prevalence of beta-lactam (cephalosporins or carbapenems) or colistin resistant bacteria. Those were isolated from urine samples in two private polyclinics located in the Sfax region, in southern Tunisia. From September 2021 to August 2022, 116 strains resistant to β-lactams or colistin were isolated, identified by MALDI-TOF, and their antibiotic susceptibility was assessed by disk diffusion method. Resistance genes were detected by real-time PCR, standard PCR, and sequencing. The results revealed that the 116 strains consisted predominantly of Enterobacteriaceae (92.2 %) and non-fermenting bacteria (7.8 %). Among these strains, 21 (18.1 %) were resistant to carbapenems, three (2.7 %) to colistin, including two strains of Klebsiella pneumoniae (1.7 %) exhibiting resistance to both carbapenems and colistin. In Enterobacteriaceae, bla(CTX-A), bla(SHV), and bla(TEM) were found in 79.5 %, 46.7 %, and 40.2 % of strains, respectively. For these strains, the minimum inhibitory concentrations (MICs) of imipenem and ertapenem ranged from >32 to 6 μg/mL and > 32 to 2 μg/mL, respectively, with bla(OXA-48) and bla(NDM) detected in 21.7 % and 19.6 % of isolates, respectively. Seven A. baumannii isolates resistant to imipenem and meropenem (MICs >32 μg/mL and 8 μg/mL, respectively) carried bla(OXA-23) (n = 5) and bla(OXA-24) (n = 2). In addition, mutations in the mgrB gene conferring colistin resistance were identified in two isolates. Two K. pneumoniae were colistin-resistant and carried the bla(OXA-48) gene. These results highlight the urgency of developing new strategies for the identification and surveillance of pathogenic strains in humans to effectively combat this growing public health threat in Tunisia.202540553790
1119160.9993Prevalence and molecular characterization of antibiotic resistance and associated genes in Klebsiella pneumoniae isolates: A clinical observational study in different hospitals in Chattogram, Bangladesh. OBJECTIVE: This study was performed to investigate the prevalence of multidrug resistance and molecular characterization of Klebsiella pneumoniae (KPN) from clinical isolates in the southern region of Bangladesh. Additional analysis of the prevalence of blaNDM-1, blaSHV-11, uge genes of KPN was also carried out among these clinical isolates. METHOD: The study was carried out using 1000 clinical isolates collected from two different hospitals of Chattogram. A drug susceptibility test was performed by the disk diffusion method to detect KPN's response to 16 antibiotics. The presence of antibiotic-resistant and (or) virulent genes blaNDM-1, blaSHV-11, uge were investigated using the PCR technique. Isolates having blaNDM-1, blaSHV-11, uge gene were further validated by sequencing followed by phylogenetic analysis. Phylogenetic relationships among these isolates were determined by Clustal omega and MEGA7. RESULT: A total of 79%, 77%, 74.9%, 71%, 66% and 65% isolates exhibited resistance against cefuroxime, cefixime, cefotaxime, ceftazidime, cefepime and ceftriaxone respectively. The frequency of resistance to other antibiotics varied from 26.5% to 61.8%. PCR analysis showed that 64% of strains harbored blaNDM-1 gene, and 38% strains harbored blaSHV-11 gene. Moreover, 47% of samples were carrying uge gene, and 19% of samples carried blaNDM-1, blaSHV-11, uge genes together. CONCLUSION: In this study, we've analysed the pattern of expression as well as prevalence of blaNDM-1, blaSHV-11, and uge genes in Klebsiella isolates. Upon molecular and statistical analysis, we found a high prevalence of multi-drug resistance KPN strains in the isolates. The Klebsiella isolates were confirmed to harbor multiple ESBL genes and 64% of the isolates were found to be producing NDM-1. As multidrug resistance is an alarming issue, continuous surveillance and routine clinical detection of resistant bacteria and plasmids are necessary to prevent catastrophic public health incidents.202134506611
1047170.9993Biofilm 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.202337004897
2111180.9993Antimicrobial 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.201931819545
1242190.9993An Update on Wastewater Multi-Resistant Bacteria: Identification of Clinical Pathogens Such as Escherichia coli O25b:H4-B2-ST131-Producing CTX-M-15 ESBL and KPC-3 Carbapenemase-Producing Klebsiella oxytoca. Wastewater treatment plants (WWTPs) are significant reservoirs of bacterial resistance. This work aims to identify the determinants of resistance produced by Gram-negative bacteria in the influent and effluent of two WWTPs in Portugal. A total of 96 wastewater samples were obtained between 2016 and 2019. The numbers of total aerobic and fecal contamination bacteria were evaluated, and genomic features were searched by polymerase chain reaction (PCR) and Next-Generation Sequencing (NGS). Enterobacteriaceae corresponded to 78.6% (n = 161) of the 205 isolates identified by 16sRNA. The most frequent isolates were Escherichia spp. (57.1%, n = 117), followed by Aeromonas spp. (16.1%, n = 33) and Klebsiella spp. (12.7%, n = 26). The remaining 29 isolates (14.1%) were distributed across 10 different genera. Among the 183 resistant genes detected, 54 isolates produced extended spectrum β-lactamases (ESBL), of which bla(CTX-M-15) was predominant (37 isolates; 68.5%). A KPC-3 carbapenemase-producing K. oxytoca was identified (n = 1), with bla(KPC-3) included in a transposon Tn4401 isoform b. A higher number of virulence genes (VG) (19 genes) was found in the E. coli 5301 (O25b-ST131-B2) isolate compared with a commensal E. coli 5281 (O25b-ST410-A) (six genes). Both shared five VG [Enterobactin; Aerobactin, CFA/1 (clade α); Type1 (clade γ1); Type IV]. In conclusion, this work highlights the role of relevant clinical bacteria in WWTPs, such as KPC-3-producing K. oxytoca, and, for the first time, a CTX-M-15-producing Ochromobactrum intermedium, a human opportunistic pathogen, and a SED-1-producing Citrobacter farmeri, an uncommon CTX-M-type extended-spectrum beta-lactamase.202133799747