Multidrug Resistance Profiles and Resistance Mechanisms to β-Lactams and Fluoroquinolones in Bacterial Isolates from Hospital Wastewater in Bangladesh. - Related Documents




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194901.0000Multidrug Resistance Profiles and Resistance Mechanisms to β-Lactams and Fluoroquinolones in Bacterial Isolates from Hospital Wastewater in Bangladesh. Multidrug resistance (MDR) is one of the deadliest public health concerns of the 21st century, rendering many powerful antibiotics ineffective. The current study provides important insights into the prevalence and mechanisms of antibiotic resistance in hospital wastewater isolates. In this study, we determined the MDR profile of 68 bacterial isolates collected from five different hospitals in Dhaka, Bangladesh. Of them, 48 bacterial isolates were identified as Enterobacteriaceae. Additionally, we investigated the prevalence and distribution of five beta-lactam resistance genes, as well as quinolone resistance mechanisms among the isolates. The results of this study showed that 87% of the wastewater isolates were resistant to at least three different antibiotic classes, as revealed using the disc diffusion method. Resistance to β-lactams was the most common, with 88.24% of the isolates being resistant, closely followed by macrolides (80.88% resistant). Polymyxin was found to be the most effective against wastewater isolates, with 29.41% resistant isolates. The most common β-lactam resistance genes found in wastewater isolates were bla(TEM) (76.09%), bla(CTX-M1) (71.74%), and bla(NDM) (67.39%). Two missense mutations in the quinolone resistance-determining region (QRDR) of gyrA (S83L and D87N) and one in both parC (S80I) and parE (S458A) were identified in all isolates, and one in parE (I529L), which had not previously been identified in Bangladesh. These findings suggest that hospital wastewater acts as an important reservoir of antibiotic-resistant bacteria wherein resistance mechanisms to β-lactams and fluoroquinolones are obvious. Our data also emphasize the need for establishing a nationwide surveillance system for antibiotic resistance monitoring to ensure that hospitals sanitize their wastewater before disposal, and regulation to ensure hospital wastewater is kept away from community settings.202337623228
194810.9999Identification and Characterization of Cefotaxime Resistant Bacteria in Beef Cattle. Third-generation cephalosporins are an important class of antibiotics that are widely used in treatment of serious Gram-negative bacterial infections. In this study, we report the isolation of bacteria resistant to the third-generation cephalosporin cefotaxime from cattle with no previous cefotaxime antibiotic exposure. The prevalence of cefotaxime-resistant bacteria was examined by a combination of culture based and molecular typing methods in beef cattle (n = 1341) from 8 herds located in North Central Florida. The overall prevalence of cefotaxime-resistant bacteria was 15.8% (95% CI: 13.9, 17.8), varied between farms, and ranged from 5.2% to 100%. A subset of isolates (n = 23) was further characterized for the cefotaxime minimum inhibitory concentration (MIC) and antibiotic susceptibility against 10 different antibiotics, sequencing of nine β- lactamase genes, and species identification by 16S rRNA sequencing. Most of the bacterial isolates were resistant to cefotaxime (concentrations, > 64 μg/mL) and showed high levels of multi-drug resistance. Full length 16S rRNA sequences (~1300 bp) revealed that most of the isolates were not primary human or animal pathogens; rather were more typical of commensal, soil, or other environmental origin. Six extended spectrum β-lactamase (ESBL) genes identical to those in clinical human isolates were identified. Our study highlights the potential for carriage of cefotaxime resistance (including "human" ESBL genes) by the bacterial flora of food animals with no history of cefotaxime antibiotic exposure. A better understanding of the origin and transmission of resistance genes in these pre-harvest settings will be critical to development of strategies to prevent the spread of antimicrobial resistant microorganisms to hospitals and communities.201627642751
170920.9999High prevalence of bla(VIM-1) gene in bacteria from Brazilian soil. This study investigated bacteria from soil samples to (i) determine the main bacterial genera and species having resistance to carbapenem and other β-lactams and (ii) establish if the mechanism of resistance was due to the production of metallo-β-lactamases. The isolates were characterized by PCR for metallo-β-lactamases and integrons, by antimicrobial susceptibility testing, and by sequencing. The antimicrobial profile of 40 imipenem-resistant Gram-positive soil isolates from all Brazilian regions demonstrated that 31 (77.5%) of them were multidrug resistant. Among the 40 isolates, 19 presented the bla(VIM) gene and class 1 integrons by PCR. Six of the 19 isolates were identified as Paenibacillus sp., 12 as Bacillus sp., and just 1 was classified as Staphylococcus sp., by sequencing of the 16S rRNA gene. These results suggest that bacteria from soil can act as a source of bla(VIM-1) genes, representing a threat to public health.201627392282
161930.9999Evidence of colistin resistance genes (mcr-1 and mcr-2) in wild birds and its public health implication in Egypt. BACKGROUND: Antimicrobial resistance has become one of the most severe global threats to human and veterinary Medicine. colistin is an effective therapeutic agent against multi-drug-resistant pathogens. However, the discovery of transferable plasmids that confer resistance to colistin (mcr-1) has led to challenges in medical science. This study describes the role of wild birds in the harbouring and environmental spread of colistin-resistant bacteria, which could pose a potential hazard to human and animal health. METHODS: In total, 140 faecal samples from wild birds (migratory and resident birds) were tested. Twenty surface water samples were collected from the area in which wild bird trapping was conducted, and 50 human stool samples were collected from individuals residing near the surface water sources and farm buildings. Isolation and identification of Enterobacteriaceae and Pseudomonas aeruginosa from the different samples were performed using conventional culture techniques and biochemical identification. PCR amplification of the mcr genes was performed in all positive isolates. Sequencing of mcr-1 genes from three randomly selected E. coli carrying mcr-1 isolates; wild birds, water and humans was performed. RESULT: The bacteriological examination of the samples showing isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca and P. aeruginosa. The results of multiplex PCR of the mcr genes revealed that E. coli was the most prevalent gram-negative bacterium harbouring the mcr genes, whereas a low prevalence was observed for K. pneumoniae. The prevalence of mcr-1 in resident birds, migratory birds, water sources and humans were 10.4, 20,16.6 and 9.6% while the prevalence of mcr-2 were 1.4, 3.6, 11.1 and 9.6%, respectively. Sequencing of the mcr-1 gene from the three E. coli carrying mcr-1 isolates indicated a possible correlation between the wild bird and surface water isolates. CONCLUSION: The detection of mcr-1-positive bacteria in wild birds in Egypt indicates the possible environmental dissemination of this gene through bird activity. The impact of the interaction between domestic and wild animals on public health cannot be overlooked.201931827778
162240.9999Antimicrobial Susceptibility and Frequency of bla and qnr Genes in Salmonella enterica Isolated from Slaughtered Pigs. Salmonella enterica is known as one of the most common foodborne pathogens worldwide. While salmonellosis is usually self-limiting, severe infections may require antimicrobial therapy. However, increasing resistance of Salmonella to antimicrobials, particularly fluoroquinolones and cephalosporins, is of utmost concern. The present study aimed to investigate the antimicrobial susceptibility of S. enterica isolated from pork, the major product in Philippine livestock production. Our results show that both the qnrS and the bla(TEM) antimicrobial resistance genes were present in 61.2% of the isolates. While qnrA (12.9%) and qnrB (39.3%) were found less frequently, co-carriage of bla(TEM) and one to three qnr subtypes was observed in 45.5% of the isolates. Co-carriage of bla(TEM) and bla(CTX-M) was also observed in 3.9% of the isolates. Antimicrobial susceptibility testing revealed that the majority of isolates were non-susceptible to ampicillin and trimethoprim/sulfamethoxazole, and 13.5% of the isolates were multidrug-resistant (MDR). MDR isolates belonged to either O:3,10, O:4, or an unidentified serogroup. High numbers of S. enterica carrying antimicrobial resistance genes (ARG), specifically the presence of isolates co-carrying resistance to both β-lactams and fluoroquinolones, raise a concern on antimicrobial use in the Philippine hog industry and on possible transmission of ARG to other bacteria.202134943653
87950.9999Detection of New Delhi metallo-beta-lactamase enzyme gene bla (NDM-1) associated with the Int-1 gene in Gram-negative bacteria collected from the effluent treatment plant of a tuberculosis care hospital in Delhi, India. BACKGROUND: Organisms possessing the bla (NDM-1) gene (responsible for carbapenem resistance) with a class-1 integron can acquire many other antibiotic resistance genes from the community sewage pool and become multidrug-resistant superbugs. In this regard, hospital sewage, which contains a large quantity of residual antibiotics, metals and disinfectants, is being recognized as a significant cause of antimicrobial resistance (AMR) origination and spread across the major centres of the world and is thus routinely investigated as a marker for tracing the origin of drug resistance. Therefore, in this study, an attempt has been made to identify and characterize the carbapenem-resistant microbes associated with integron genes amongst the organisms isolated from the effluent treatment plant (ETP) installed in a tertiary respiratory care hospital in Delhi, India. METHODS: One hundred and thirty-eight organisms belonging to Escherichia , Klebsiella , Pseudomonas and Acinetobacter spp. were collected from the incoming and outgoing sewage lines of the ETP. Carbapenem sensitivity and characterization was performed by the imipenem and imipenem-EDTA disc diffusion method. Later DNA extraction and PCR steps were performed for the Int-1 and bla (NDM-1) genes. RESULTS: Of the 138 organisms, 86 (62.3 %) were imipenem-resistant (P<0.05). One hundred and twenty-four (89.9 %) organisms had one or both of the genes. Overall, the bla (NDM-1) gene (genotypic resistance) was present in 71 % (98/138) of organisms. 53.6 % (74/138) organisms were double gene-positive (bla (NDM-1) + Int-1), of which 40 were producing the metallo-beta-lactamase enzyme, making up almost 28.9 % (40/138) of the collected organisms. CONCLUSION: The current study strengthens the hypothesis that Carbapenem resistant organisms are in a high-circulation burden through the human gut and hospital ETPs are providing an environment for resistance origination and amplification.202032974589
274660.9999Antibiotic Resistance and Antibiotic Resistance Genes in Escherichia coli Isolates from Hospital Wastewater in Vietnam. The environmental spread of antibiotic-resistant bacteria has been recognised as a growing public health threat for which hospitals play a significant role. The aims of this study were to investigate the prevalence of antibiotic resistance and antibiotic resistance genes (ARGs) in Escherichia coli isolates from hospital wastewater in Vietnam. Wastewater samples before and after treatment were collected using continuous sampling every month over a year. Standard disk diffusion and E-test were used for antibiotic susceptibility testing. Extended-spectrum beta-lactamase (ESBL) production was tested using combined disk diffusion. ARGs were detected by polymerase chain reactions. Resistance to at least one antibiotic was detected in 83% of isolates; multidrug resistance was found in 32%. The highest resistance prevalence was found for co-trimoxazole (70%) and the lowest for imipenem (1%). Forty-three percent of isolates were ESBL-producing, with the bla(TEM) gene being more common than bla(CTX-M). Co-harbouring of the bla(CTX-M), bla(TEM) and qepA genes was found in 46% of isolates resistant to ciprofloxacin. The large presence of antibiotic-resistant E. coli isolates combined with ARGs in hospital wastewater, even post-treatment, poses a threat to public health. It highlights the need to develop effective processes for hospital wastewater treatment plants to eliminate antibiotic resistant bacteria and ARGs.201728661465
194770.9999Search for carbapenem-resistant bacteria and carbapenem resistance genes along swine food chains in Central Italy. The presence of carbapenem-resistant bacteria and carbapenem resistance genes (CRGs) in livestock is increasing. To evaluate the presence of carbapenemase-producing Enterobacteriaceae (CPE) and the main CRGs along swine food chains of the Marche Region (Central Italy), samples of faeces, feed, and animal-food derived products were collected from seven small/medium, medium, and large-scale pig farms. A total of 191 samples were analysed using a culture-dependent method, with the aim of isolating CPE. Isolates were analysed for their resistance to carbapenems using a modified Hodge test and the microdilution method for the minimum inhibitory concentration (MIC) determination. Moreover, the extraction of microbial DNA from each sample was performed to directly detect selected CRGs via qPCR. Among the 164 presumptive resistant isolates, only one strain from a liver sample, identified as Aeromonas veronii, had an ertapenem MIC of 256 μg/mL and carried a carbapenemase- (cphA) and a β-lactamase- (blaOXA-12) encoding genes. A low incidence of CRGs was found; only nine and four faecal samples tested positive for blaNDM-1 and blaOXA-48, respectively. Overall, the importance of monitoring CPE and CRGs in livestock and their food chains should be stressed to control all potential non-human CPE and CRGs reservoirs and to determine safety levels for human health.202438181018
195080.9999In treacherous waters: detection of colistin-resistant bacteria in water and plastic litter from a recreational estuary. Colistin resistance poses a major therapeutic challenge and resistant strains have now been reported worldwide. However, the occurrence of such bacteria in aquatic environments is considerably less understood. This study aimed to isolate and characterize colistin-resistant strains from water and plastic litter collected in an urban recreational estuary. Altogether, 64 strains with acquired colistin resistance were identified, mainly Acinetobacter spp. and Enterobacter spp. From these, 40.6% were positive for at least one mcr variant (1-9), 26.5% harbored, extended-spectrum beta-lactamases, 23.4% harbored, sulfonamide resistance genes, and 9.3% harbored, quinolone resistance genes. merA, encoding mercury resistance, was detected in 10.5% of these strains, most of which were also strong biofilm producers. The minimum inhibitory concentration toward colistin was determined for the mcr-positive strains and ranged from 2 to ≥512 µg ml-1. Our findings suggest that Gram-negative bacteria highly resistant to a last-resort antimicrobial can be found in recreational waters and plastic litter, thereby evidencing the urgency of the One Health approach to mitigate the antimicrobial resistance crisis.202439227173
195190.9999Colistin-resistant Escherichia coli with mcr genes in the livestock of rural small-scale farms in Ecuador. OBJECTIVE: Emergence and dissemination of colistin-resistant (Co-R) bacteria harboring mobile colistin resistance genes pose a threat for treatment of infections caused by multi-drug resistant bacteria. Although the worldwide spread of Co-R bacteria is known, the precise state of Co-R bacterial dissemination in livestock of Andean countries remains unclear. Therefore, we investigated mcr-containing Co-R Escherichia coli dissemination in livestock on small-scale farms in two socioecologically different regions of Ecuador: the Amazonian rain-forest and the Pacific Coast. RESULTS: Sixty-six rectal swab samples from 34 pigs and 32 chickens, from five farms in the two regions, were assessed for the dissemination of Co-R E. coli using the selective medium CHROMagar™ COL-APSE. mcr-containing Co-R E. coli were detected in the specimens at a high rate (47%; 31/66), but the detection rates of the two regions were not statistically different. Both chickens and pigs showed similar detection rates. All Co-R E. coli isolates harbored mcr-1. The minimum inhibitory concentrations of colistin were ≥ 8 mg/L, and 67.7% (21/31) of the Co-R isolates were multi-drug resistant. Pulsed-field gel electrophoresis revealed the limited relation between isolates. Thus, we revealed the high rate of widespread dissemination of Co-R bacteria in livestock regardless of the socioecological conditions in Ecuador.201930832731
1965100.9999Phenotypic Investigation of Florfenicol Resistance and Molecular Detection of floR Gene in Canine and Feline MDR Enterobacterales. Florfenicol is a promising antibiotic for use in companion animals, especially as an alternative agent for infections caused by MDR bacteria. However, the emergence of resistant strains could hinder this potential. In this study, florfenicol resistance was investigated in a total of 246 MDR Enterobacterales obtained from canine and feline clinical samples in Greece over a two-year period (October 2020 to December 2022); a total of 44 (17,9%) florfenicol-resistant strains were recognized and further investigated. Most of these isolates originated from urine (41.9%) and soft tissue (37.2%) samples; E. coli (n = 14) and Enterobacter cloacae (n = 12) were the predominant species. The strains were examined for the presence of specific florfenicol-related resistance genes floR and cfr. In the majority of the isolates (31/44, 70.5%), the floR gene was detected, whereas none carried cfr. This finding creates concerns of co-acquisition of plasmid-mediated florfenicol-specific ARGs through horizontal transfer, along with several other resistance genes. The florfenicol resistance rates in MDR isolates seem relatively low but considerable for a second-line antibiotic; thus, in order to evaluate the potential of florfenicol to constitute an alternative antibiotic in companion animals, continuous monitoring of antibiotic resistance profiles is needed in order to investigate the distribution of florfenicol resistance under pressure of administration of commonly used agents.202438393089
1830110.9999Shifts in bla genes and Class 1 integron prevalence in beta-lactamase-producing bacteria before and after the COVID-19 pandemic in Mendoza, Argentina. This study analyzes the molecular epidemiology of bla genes and Class 1 integron in broad-spectrum beta-lactamase (BSBL) and extended-spectrum beta-lactamase (ESBL) producing strains of bacteria isolated from clinical samples of hospitalized and ambulatory patients before and after the COVID-19 pandemic. Isolates obtained in two periods were compared: the first corresponding to the years November 2019-March 2020, and the second to the years November 2021-April 2022. We evaluate changes in resistance patterns of antibiotics associated with pressures on the healthcare system and social lockdowns. A total of 156 isolates were analyzed: 78 from the first period (61 hospitalized, 17 ambulatory) and 78 from the second period (47 hospitalized, 31 ambulatory). Escherichia coli and Klebsiella pneumoniae were the predominant bacterial species, representing 85% of the isolates in both periods. The frequency of ambulatory ESBL-producing isolates increased significantly, from 22% (17/78) to 40% (31/78; P < 0.01) in the second period. The prevalence of bla(SHV) increased from 24% (19/78) to 72% (56/78; P < 0.01) in the second period, while the bla(CTX-M-2) group, absent in the first period, was detected in 43% (34/78) of isolates from the second period. Strains from the second period exhibited greater genetic complexity, with an increased prevalence of combinations involving three or more bla genes, including isolates carrying up to five of such genes. Class 1 integron showed a strong correlation with resistance to ciprofloxacin and trimethoprim-sulfamethoxazole. The gene bla(OXA-1), previously associated with resistance to beta-lactamase inhibitors, did not show a clear pattern in the second period.IMPORTANCEAntimicrobial resistance associated with the production of extended-spectrum beta-lactamase (ESBL) represents a critical global health challenge, particularly due to the limited development of new antibiotics. This is the first report from Argentina's central-west region examining the prevalence of beta-lactamase-encoding genes, providing a framework for future research. Our findings reveal a significant increase in bacteria with the ESBL phenotype, particularly among ambulatory populations post-pandemic, suggesting a concerning spread of multidrug-resistant bacteria outside hospital environments. This could compromise empirical antibiotic treatments for ambulatory patients, increasing the risk of severe complications. Our results highlight the urgent need for ongoing surveillance to detect virulent strains before clonal spread or horizontal gene transfer occurs in the community. They also emphasize the importance of strategies to ensure the prudent use of antimicrobials and mitigate the increasing prevalence of resistance genes, which threatens the effectiveness of current therapeutic options.202540662585
1964120.9999Antimicrobial resistance of pet-derived bacteria in China, 2000-2020. With the rapid growth of the pet industry in China, bacterial infectious diseases in pets have increased, highlighting the need to monitor antimicrobial resistance (AMR) in pet-derived bacteria to improve the diagnosis and treatment. Before the establishment of the China Antimicrobial Resistance Surveillance Network for Pets (CARPet) in 2021, a comprehensive analysis of such data in China was lacking. Our review of 38 point-prevalence surveys conducted between 2000 and 2020 revealed increasing trends in AMR among pet-derived Escherichia coli, Klebsiella pneumoniae, Staphylococcus spp., Enterococcus spp., and other bacterial pathogens in China. Notable resistance to β-lactams and fluoroquinolones, which are largely used in both pets and livestock animals, was observed. For example, resistance rates for ampicillin and ciprofloxacin in E. coli frequently exceeded 50.0%, with up to 41.3% of the isolates producing extended-spectrum β-lactamases. The emergence of carbapenem-resistant K. pneumoniae and E. coli, carrying bla(NDM) and bla(OXA) genes, highlighted the need for vigilant monitoring. The detection rate of SCCmec (Staphylococcal Cassette Chromosome mec), a genetic element associated with methicillin resistance, in Staphylococcus pseudintermedius isolated from pets in China was found to be over 40.0%. The resistance rate of E. faecalis to vancomycin was 2.1% (5/223) in East China, which was higher than the detection rate of human-derived vancomycin-resistant Enterococcus (0.1%, 12/11,215). Establishing the national AMR surveillance network CARPet was crucial, focusing on representative cities, diverse clinical samples, and including both commonly used antimicrobial agents in veterinary practice and critically important antimicrobial agents for human medicine, such as carbapenems, tigecycline, and vancomycin.202540135877
1618130.9999Molecular Characterization of Multidrug-Resistant Escherichia coli from Fecal Samples of Wild Animals. Antimicrobial resistance (AMR) surveillance in fecal Escherichia coli isolates from wildlife is crucial for monitoring the spread of this microorganism in the environment and for developing effective AMR control strategies. Wildlife can act as carriers of AMR bacteria and spread them to other wildlife, domestic animals, and humans; thus, they have public health implications. A total of 128 Escherichia coli isolates were obtained from 66 of 217 fecal samples obtained from different wild animals using media without antibiotic supplementation. Antibiograms were performed for 17 antibiotics to determine the phenotypic resistance profile in these isolates. Extended-spectrum β-lactamase (ESBL) production was tested using the double-disc synergy test, and 29 E. coli strains were selected for whole genome sequencing. In total, 22.1% of the wild animals tested carried multidrug-resistant E. coli isolates, and 0.93% (2/217) of these wild animals carried E. coli isolates with ESBL-encoding genes (bla(CTX-M-65), bla(CTX-M-55), and bla(EC-1982)). The E. coli isolates showed the highest resistance rates to ampicillin and were fully susceptible to amikacin, meropenem, ertapenem, and imipenem. Multiple resistance and virulence genes were detected, as well as different plasmids. The relatively high frequency of multidrug-resistant E. coli isolates in wildlife, with some of them being ESBL producers, raises some concern regarding the potential transmission of antibiotic-resistant bacteria among these animals. Gaining insights into antibiotic resistance patterns in wildlife can be vital in shaping conservation initiatives and developing effective strategies for responsible antibiotic use.202439453061
877140.9999Drug resistance analysis of three types of avian-origin carbapenem-resistant Enterobacteriaceae in Shandong Province, China. Animal-derived Enterobacteriaceae bacteria such as Escherichia coli (E. coli), Proteus mirabilis (P. mirabilis), and Klebsiella pneumoniae (K. pneumoniae) are important food-borne zoonotic bacilli that exist widely in the broiler-breeding industry. Although carbapenem antibiotics are considered to be the last line of defense against multidrug-resistant bacteria, carbapenem-resistant Enterobacteriaceae (CRE) break through them. In our study, we therefore, examined the prevalence of CRE and characteristics of antimicrobial resistance in 6 conventional broiler-fattening farms in Shandong Province, China. Our study revealed isolation rates of 3.57% (6/168) for carbapenem-resistant E. coli, 10% (5/50) for carbapenem-resistant P. mirabilis, and 3.03% (1/33) for carbapenem-resistant K. pneumoniae. All 12 CRE bacterial strains showed varying degrees of resistance to 27 antibiotics in 8 classes and were multidrug-resistant. The rate of the strains containing bla(NDM) genes, at 91.67% (11/12), was especially high. Among other results, the carrying rate of integrons in CRE bacteria was 91.67% (11/12), and 2 strains carried both class I and class II integrons, which accelerated the lateral transmission of resistant bacteria. Our first-ever finding of the 3 CRE bacteria E. coli, P. mirabilis, and K. pneumoniae on the same broiler farm suggests that poultry-derived CRE strains may pose a risk to humans. Moreover, our findings from surveillance can inform current understandings of the prevalence and characteristics of multidrug-resistant CRE in Shandong Province and, in turn, help to curb threats to food safety and public health and better prevent and control infectious zoonotic diseases.202336682131
2255150.9999Diversity and metallo-β-lactamase-producing genes in Pseudomonas aeruginosa strains isolated from filters of household water treatment systems. The microbiological quality of drinking water has long been a critical element in public health. Considering the high clinical relevance of Pseudomonas aeruginosa, we examined the filters of household water treatment systems for its presence and characteristics to determine the systems' efficiency in eliminating the bacteria. In total, filters of 50 household water treatment systems were examined. Microbiological and molecular methods were used for the detection and confirmation of P. aeruginosa isolates. Random Amplification of Polymorphic DNA-polymerase chain reaction (RAPD-PCR) was performed to detect similarities and differences among P. aeruginosa isolates. Combined disk (CD) method and double disk synergy test (DDST) were performed to detect metallo-beta-lactamase (MBL)-producing P. aeruginosa isolates. Finally, PCR was performed to detect MBL genes in MBL-producing strains. From the 50 analyzed systems, 76 colonies of P. aeruginosa were identified. In some systems, isolated bacteria from different filters harbored similar genetic profiles, indicating that these isolates may be able to pass through the filter and reach higher filters of the system. Phenotypic tests revealed 7 (9.2%) MBL-producing strains. Two isolates were positive for bla(VIM-1), whereas one isolate was positive for bla(NDM) and bla(IMP-1). The wide distribution of resistant phenotypes and genetic plasticity of these bacteria in household water treatment systems indicate that resistance mechanisms circulate among P. aeruginosa isolates in the environment of the filtration systems. The presence of MBL-producing genes in these systems and P. aeruginosa as a potential reservoir of these resistance genes can be a major concern for public health.201930368151
1032160.9999Molecular investigation of antibiotic resistant bacterial strains isolated from wastewater streams in Pakistan. Antibiotic resistance is a global public health issue and it is even more daunting in developing countries. The main objective of present study was to investigate molecular responses of antibiotic-resistant bacteria. The 48 bacterial strains, which were previously isolated and identified were subjected to disc diffusion and MIC (minimum inhibitory concentration) determination, followed by investigating the production of the three beta-lactamases (ESBLs (Extended-spectrum Beta-lactamases), MBLs (Metallo Beta-lactamases), AmpCs) and exploring prevalence of the two antibiotic-resistant genes (ARGs); blaTEM and qnrS. Higher MIC values were observed for penicillin(s) than that for fluoroquinolones (ampicillin > amoxicillin > ofloxacin > ciprofloxacin > levofloxacin). Resistance rates were high (58-89%) for all of the tested beta-lactams. Among the tested strains, 5 were ESBL producers (4 Aeromonas spp. and 1 Escherichia sp.), 2 were MBL producers (1 Stenotrophomonas sp. and 1 Citrobacter sp.) and 3 were AmpC producers (2 Pseudomonas spp. and 1 Morganella sp.). The ARGs qnrS2 and blaTEM were detected in Aeromonas spp. and Escherichia sp. The results highlighted the role of Aeromonas as a vector. The study reports bacteria of multidrug resistance nature in the wastewater environment of Pakistan, which harbor ARGs of clinical relevance and could present a public health concern.202032802720
1613170.9999Research note: Occurrence of mcr-encoded colistin resistance in Escherichia coli from pigs and pig farm workers in Vietnam. WHO considers colistin as a highest priority critically important drug for human health, and occurrence of colistin-resistant bacteria in livestock is of health concern. The current study determined occurrence of colistin-resistant Escherichia coli in pigs and workers at pig farms in Vietnam, and investigated the genetic background for resistance. Colistin-resistant E. coli were detected from pigs in 53/116 (45.7%) farms, and from workers taking care of the pigs in 21/94 (22.3%) farms. Colistin-resistant isolates showed MIC to colistin between 4-16 mg/L, they were multidrug resistant (99%) and resistance was caused by the presence of mcr-1 genes in 97/102 (95.1%) E. coli from pigs and in 31/34 (91.1%) isolates from humans. mcr-1 is considered a plasmid-encoded gene, but this was not confirmed in the current investigation. In total, one pig isolate carried both mcr-1 and mcr-3 genes, whereas mcr-2, mcr-4 and mcr-5 genes were not detected. Shared resistance profiles between pig and human isolates on the same farm was only observed in four farms. The study showed that commensal E. coli from pigs in Vietnam constitute a reservoir for colistin-resitant E. coli, however, further studies are needed to confirm that mcr genes are associated with plasmids and their importance for human health.202037333956
2732180.9998Biofilms in hospital effluents as a potential crossroads for carbapenemase-encoding strains. Bacterial resistance to carbapenem, which is mainly due to the successful dissemination of carbapenemase-encoding genes, has become a major health problem. Few studies have aimed to characterize the level of resistance in the environment, notably in hospital wastewater, which is a likely hotspot for exchange of antibiotic resistance genes. In this work, we looked for the presence of imipenem-resistant bacteria and imipenem in the effluent of the teaching hospital of Clermont-Ferrand, France. Selective growth of bacteria from 14-day old biofilms formed in the pipe sewer showed that 22.1% of the isolates were imipenem-resistant and identified as Aeromonas (n = 23), Pseudomonas (n = 10), Stenotrophomonas (n = 4) and Acinetobacter (n = 1). Fifteen of these strains harbored acquired carbapenemase-encoding genes bla(VIM) (n = 11), bla(OXA-48) (n = 2), bla(GES) (n = 1), bla(NDM) (n = 1). All isolates also harbored associated resistances to aminoglycosides, fluoroquinolones and/or tetracyclin. S1-nuclease pulsed-field gel electrophoresis analysis of eight selected isolates showed that four of them harbored one to two plasmids of molecular weight between 48.5 Kb and 194 Kb. In vitro transformation assays evidenced the presence of bla(VIM) and bla(NDM) on plasmids with the bla(VIM) harboring 80 Kb plasmid having conjugative capacity. The predicted environmental concentration of imipenem in the hospital effluent was 3.16 μg/L, suggesting that biofilm bacteria are subjected to sub-MICs of imipenem within the effluent. However, no imipenem molecule was detected in the hospital effluent, probably owing to its instability: in vitro assays indicated that imipenem's biological activity was no longer detectable after 45 h of storage. However, the predictive value of the hazard quotient relative to the development of resistance was >1.0 (HQr = 28.9 ± 1.9), which indicates a possible risk. The presence of carbapenemase-encoding genes in hospital effluent biofilm strains and their ability to transfer are therefore a potential hazard that should not be neglected and points to the need for monitoring antibiotic resistance in hospital wastewater.201930530220
1620190.9998A survey of antimicrobial-resistant Escherichia coli prevalence in wild mammals in Japan using antimicrobial-containing media. The emergence and spread of antimicrobial-resistant bacteria and resistance genes pose serious human and animal health concerns. Therefore, to control antimicrobial-resistant bacteria in the environment, the status of antimicrobial resistance of Escherichia coli in a variety of wild mammals and their prevalence were examined using antimicrobial-containing media. In total, 750 isolates were obtained from 274/366 (74.9%) wild mammals, and antimicrobial-resistant E. coli was detected in 37/750 isolates (4.9%) from 7 animal species (26/366 [7.1%] individuals). Using antimicrobial-containing media, 14 cefotaxime (CTX)- and 35 nalidixic acid-resistant isolates were obtained from 5 (1.4%) and 17 (4.6%) individuals, respectively. CTX-resistant isolates carried bla(CTX-M-27), bla(CTX-M-55), bla(CTX-M-1), and bla(CMY-2), with multiple resistance genes. Fluoroquinolone-resistant isolates had multiple mutations in the quinolone-resistance determining regions of gyrA and parC or qnrB19. Most resistant isolates exhibited resistance to multiple antimicrobials. The prevalence of antimicrobial-resistant bacteria observed in wild mammals was low; however, it is essential to elucidate the causative factors related to the low prevalence and transmission route of antimicrobial-resistant bacteria/resistance genes released from human activities to wild animals and prevent an increase in their frequency.202236310042