Biofilms in hospital effluents as a potential crossroads for carbapenemase-encoding strains. - Related Documents




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273201.0000Biofilms 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
87910.9999Detection 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
273120.9999Prevalence of tetracycline resistance genes among multi-drug resistant bacteria from selected water distribution systems in southwestern Nigeria. BACKGROUND: Antibiotic resistance genes [ARGs] in aquatic systems have drawn increasing attention they could be transferred horizontally to pathogenic bacteria. Water treatment plants (WTPs) are intended to provide quality and widely available water to the local populace they serve. However, WTPs in developing countries may not be dependable for clean water and they could serve as points of dissemination for antibiotic resistant bacteria. Only a few studies have investigated the occurrence of ARGs among these bacteria including tetracycline resistance genes in water distribution systems in Nigeria. METHODOLOGY: Multi-drug resistant (MDR) bacteria, including resistance to tetracycline, were isolated from treated and untreated water distribution systems in southwest Nigeria. MDR bacteria were resistant to >3 classes of antibiotics based on break-point assays. Isolates were characterized using partial 16S rDNA sequencing and PCR assays for six tetracycline-resistance genes. Plasmid conjugation was evaluated using E. coli strain DH5α as the recipient strain. RESULTS: Out of the 105 bacteria, 85 (81 %) and 20 (19 %) were Gram- negative or Gram- positive, respectively. Twenty-nine isolates carried at least one of the targeted tetracycline resistance genes including strains of Aeromonas, Alcaligenes, Bacillus, Klebsiella, Leucobacter, Morganella, Proteus and a sequence matching a previously uncultured bacteria. Tet(A) was the most prevalent (16/29) followed by tet(E) (4/29) and tet30 (2/29). Tet(O) was not detected in any of the isolates. Tet(A) was mostly found with Alcaligenes strains (9/10) and a combination of more than one resistance gene was observed only amongst Alcaligenes strains [tet(A) + tet30 (2/10), tet(A) + tet(E) (3/10), tet(E) + tet(M) (1/10), tet(E) + tet30 (1/10)]. Tet(A) was transferred by conjugation for five Alcaligenes and two E. coli isolates. CONCLUSIONS: This study found a high prevalence of plasmid-encoded tet(A) among Alcaligenes isolates, raising the possibility that this strain could shuttle resistance plasmids to pathogenic bacteria.201526108344
273030.9999Multidrug Resistance in Quinolone-Resistant Gram-Negative Bacteria Isolated from Hospital Effluent and the Municipal Wastewater Treatment Plant. This study is aimed to assess if hospital effluents represent an important supplier of multidrug-resistant (MDR) Gram-negative bacteria that, being discharged in the municipal collector, may be disseminated in the environment and bypassed in water quality control systems. From a set of 101 non-Escherichia coli Gram-negative bacteria with reduced susceptibility to quinolones, was selected a group of isolates comprised by those with the highest indices of MDR (defined as nonsusceptibility to at least one agent in six or more antimicrobial categories, MDR ≥6) or resistance to meropenem or ceftazidime (n = 25). The isolates were identified and characterized for antibiotic resistance phenotype, plasmid-mediated quinolone resistance (PMQR) genes, and other genetic elements and conjugative capacity. The isolates with highest MDR indices were mainly from hospital effluent and comprised ubiquitous bacterial groups of the class Gammaproteobacteria, of the genera Aeromonas, Acinetobacter, Citrobacter, Enterobacter, Klebsiella, and Pseudomonas, and of the class Flavobacteriia, of the genera Chryseobacterium and Myroides. In this group of 25 strains, 19 identified as Gammaproteobacteria harbored at least one PMQR gene (aac(6')-Ib-cr, qnrB, qnrS, or oqxAB) or a class 1 integron gene cassette encoding aminoglycoside, sulfonamide, or carbapenem resistance. Most of the E. coli J53 transconjugants with acquired antibiotic resistance resulted from conjugation with Enterobacteriaceae. These transconjugants demonstrated acquired resistance to a maximum of five classes of antibiotics, one or more PMQR genes and/or a class 1 integron gene cassette. This study shows that ubiquitous bacteria, other than those monitored in water quality controls, are important vectors of antibiotic resistance and can be disseminated from hospital effluent to aquatic environments. This information is relevant to support management options aiming at the control of this public health problem.201626469134
170940.9999High 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
225550.9999Diversity 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
274560.9999Dissemination of multi-resistant Gram-negative bacteria into German wastewater and surface waters. Carbapenem antibiotics constitute the mainstay therapy of nosocomial infections with extended spectrum beta-lactamase producing Gram-negative bacteria; however, resistance against these compounds is increasing. This study was designed to demonstrate that carbapenemase-producing bacteria are disseminated from hospitals into the environment. To this end, resistant bacteria were isolated from a clinical/urban and from a rural catchment system in Germany in 2016/17. The study followed the dissemination of resistant bacteria from the wastewater through the wastewater treatment plant (WWTP) into the receiving surface waters. The bacteria were cultivated on selective agar and characterized by antibiotic testing, real-time PCR targeting carbapenemase genes and typing. Bacteria with resistance to third generation cephalosporins were isolated from all sample sites. 134 isolates harboring carbapenemase genes encoding VIM, NDM and OXA-48 and 26 XDR (extensively drug-resistant) strains with susceptibility to only one or two antibiotics were isolated from the clinical/urban system. The rural system yielded eight carbapenemase producers and no XDR strains. In conclusion, clinical wastewaters were charged with a high proportion of multidrug resistant bacteria. Although most of these bacteria were eliminated during wastewater treatment, dissemination into surface waters is possible as single carbapenemase producers were still present in the effluent of the WWTP.201829659796
194870.9999Identification 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
204880.9999The Role of Plasmids in the Multiple Antibiotic Resistance Transfer in ESBLs-Producing Escherichia coli Isolated From Wastewater Treatment Plants. We compared the diversity of extended-spectrum β-lactamases (ESBLs) producing Escherichia coli (E. coli) in wastewater of a municipal wastewater treatment plant. This was done by analyzing multiple antibiotic resistant phenotypes and genotypes. Also, we investigated the antibiotic resistance transfer mechanism of the plasmid by comparing the antibiotic resistance gene linked transfer using a conjugative test, and by analyzing the full-length DNA sequence of one plasmid. The results showed that 50 ESBLs-producing E. coli isolates were isolated from 80 wastewater samples at the rate of 62.5% (50/80), out of which 35 transconjugants were obtained with the multiple antibiotic resistant transfer rate as high as 70.0% (35/50). Multiple antibiotic resistance was shown in all transconjugants and donor bacteria, which were capable of resistance to 11 out of 15 kinds of antibiotics. Both transconjugants and donors were capable of resistance to the Ampicillin and Cefalotin at a rate of 100.00% (35/35), while the total antibiotic resistant spectrum of transconjugants narrowed at the rate of 94.29% (33/35) and broadened at the rate of 5.71% (2/35) after conjugate to the donor bacteria. PCR showed that the resistant genotypes decreased or remained unchanged when compared to donor bacteria with transconjugants while the bla(TEM) and bla(CTX-M) genes were transferred and linked at a rate of 100.00% (35/35) and the bla(SHV) gene was at the rate as high as 94.29% (33/35). However, the qnrS gene was transferred at a low rate of 4.17% (1/24). In addition, the major resistance gene subtypes were bla(TEM-) (1), bla(SHV -11) , and bla(CTX-M-15) according to sequencing and Blast comparison. Plasmid wwA8 is a closed-loop DNA molecule with 83157 bp, and contains 45 predicted genes, including three antibiotic resistant resistance genes, bla(CTX-M-15) , bla(TEM-1) and qnrS1, which can be transferred with E. coli in vitro. This study shows that E. coli isolated from wastewater was capable of transferring resistance genes and producing antibiotic resistant phenotypes. The plasmids containing different resistance genes in E. coli play an important role in the multiple antibiotic resistant transfer. Most importantly, antibiotic resistant resistance genes have different transfer efficiencies, the bla(TEM) and bla(CTX-M) genes transferred at a rate of 100.00% and linked transfer in all 35 transconjugants.201931001218
189990.9999Characteristics of plasmids in multi-drug-resistant Enterobacteriaceae isolated during prospective surveillance of a newly opened hospital in Iraq. BACKGROUND: Gram-negative multidrug-resistant (MDR) bacteria are major causes of nosocomial infections, and antibiotic resistance in these organisms is often plasmid mediated. Data are scarce pertaining to molecular mechanisms of antibiotic resistance in resource constrained areas such as Iraq. METHODOLOGY/PRINCIPAL FINDINGS: In this study, all MDR Enterobacteriaceae (n = 38) and randomly selected non-MDR counterparts (n = 41) isolated from patients, healthcare workers and environmental surfaces in a newly opened hospital in Iraq were investigated to characterize plasmids found in these isolates and determine their contribution to antibiotic resistance. Our results demonstrated that MDR E. coli and K. pneumoniae isolates harbored significantly more (≥ 3) plasmids compared to their non-MDR counterparts, which carried ≤ 2 plasmids (p<0.01). Various large plasmids (~52 to 100 kb) from representative isolates were confirmed to contain multiple resistance genes by DNA microarray analysis. Aminoglycoside (acc, aadA, aph, strA/B, and ksgA), β-lactam (bla(TEM1), bla(AMPC), bla(CTX-M-15), bla(OXA-1), bla(VIM-2) and bla(SHV)), sulfamethoxazole/trimethoprim (sul/dfr), tetracycline (tet) and chloramphenicol (cat) resistance genes were detected on these plasmids. Additionally, multiple plasmids carrying multiple antibiotic resistance genes were found in the same host strain. Genetic transfer-associated genes were identified on the plasmids from both MDR and non-MDR isolates. Seven plasmid replicon types (FII, FIA, FIB, B/O, K, I1 and N) were detected in the isolates, while globally disseminated IncA/C and IncHI1 plasmids were not detected in these isolates. CONCLUSIONS/SIGNIFICANCE: This is the first report of the characteristics of the plasmids found in Enterobacteriaceae isolated following the opening of a new hospital in Iraq. The information provided here furthers our understanding of the mechanisms of drug resistance in this specific region and their evolutionary relationship with other parts of world. The large plasmids, carrying resistance genes and transfer-associated genes, may be potential factors for regional dissemination of antibiotic resistance.201222808141
1950100.9999In 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
1914110.9999Comprehensive analysis of distribution characteristics and horizontal gene transfer elements of bla(NDM-1)-carrying bacteria. The worldwide dissemination of New Delhi metallo-β-lactamase-1 (NDM-1), which mediates resistance to almost all clinical β-lactam antibiotics, is a major public health problem. The global distribution, species, sources, and potential transfer risk of bla(NDM-1)-carrying bacteria are unclear. Results of a comprehensive analysis of literature in 2010-2022 showed that a total of 6002 bla(NDM-1) carrying bacteria were widely distributed around 62 countries with a high trend in the coastal areas. Opportunistic pathogens or pathogens like Klebsiella sp., Escherichia sp., Acinetobacter sp. and Pseudomonas sp. were the four main species indicating the potential microbial risk. Source analysis showed that 86.45 % of target bacteria were isolated from the source of hospital (e.g., Hospital patients and wastewater) and little from surface water (5.07 %) and farms (3.98 %). A plasmid-encoded bla(NDM-1)Acinetobacter sp. with the resistance mechanisms of antibiotic efflux pump, antibiotic target change and antibiotic degradation was isolated from the wastewater of a typical tertiary hospital. Insertion sequences (IS3 and IS30) located in the adjacent 5 kbp of bla(NDM-1)-ble(MBL) gene cluster indicating the transposon-mediated horizontal gene transfer risk. These results showed that the worldwide spread of bla(NDM-1)-carrying bacteria and its potential horizontal gene transfer risk deserve good control.202438906294
1913120.9999Citrobacter spp. and Enterobacter spp. as reservoirs of carbapenemase bla(NDM) and bla(KPC) resistance genes in hospital wastewater. Antibiotic resistance has emerged as a global threat to public health, generating a growing interest in investigating the presence of antibiotic-resistant bacteria in environments influenced by anthropogenic activities. Wastewater treatment plants in hospital serve as significant reservoirs of antimicrobial-resistant bacteria, where a favorable environment is established, promoting the proliferation and transfer of resistance genes among different bacterial species. In our study, we isolated a total of 243 strains from 5 hospital wastewater sites in Mexico, belonging to 21 distinct Gram-negative bacterial species. The presence of β-lactamase was detected in 46.9% (114/243) of the isolates, which belonging to the Enterobacteriaceae family. We identified a total of 169 β-lactamase genes; bla(TEM) in 33.1%, bla(CTX-M) in 25.4%, bla(KPC) in 25.4%, bla(NDM) 8.8%, bla(SHV) in 5.3%, and bla(OXA-48) in 1.1% distributed in 12 different bacteria species. Among the 114 of the isolates, 50.8% were found to harbor at least one carbapenemase and were discharged into the environment. The carbapenemase bla(KPC) was found in six Citrobacter spp. and E. coli, while bla(NDM) was detected in two distinct Enterobacter spp. and E. coli. Notably, bla(NDM-1) was identified in a 110 Kb IncFII conjugative plasmid in E. cloacae, E. xiangfangensis, and E. coli within the same hospital wastewater. In conclusion, hospital wastewater showed the presence of Enterobacteriaceae carrying a high frequency of carbapenemase bla(KPC) and bla(NDM). We propose that hospital wastewater serves as reservoirs for resistance mechanism within bacterial communities and creates an optimal environment for the exchange of this resistance mechanism among different bacterial strains. IMPORTANCE: The significance of this study lies in its findings regarding the prevalence and diversity of antibiotic-resistant bacteria and genes identified in hospital wastewater in Mexico. The research underscores the urgent need for enhanced surveillance and prevention strategies to tackle the escalating challenge of antibiotic resistance, particularly evident through the elevated frequencies of carbapenemase genes such as bla(KPC) and bla(NDM) within the Enterobacteriaceae family. Moreover, the identification of these resistance genes on conjugative plasmids highlights the potential for widespread transmission via horizontal gene transfer. Understanding the mechanisms of antibiotic resistance in hospital wastewater is crucial for developing targeted interventions aimed at reducing transmission, thereby safeguarding public health and preserving the efficacy of antimicrobial therapies.202439012101
1951130.9999Colistin-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
1949140.9998Multidrug 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
1965150.9998Phenotypic 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
2690160.9998Characterization of Cefotaxime- and Ciprofloxacin-Resistant Commensal Escherichia coli Originating from Belgian Farm Animals Indicates High Antibiotic Resistance Transfer Rates. Food-producing animals represent one of the sources of antibiotic resistant commensal bacteria. There is an increasing awareness that these bacteria might have the potential to transfer their resistance genes to other (pathogenic) bacteria. In this study, 50 commensal Escherichia coli strains originating from food-producing animals and resistant to the "highest priority, critically important antibiotics" cefotaxime and/or ciprofloxacin, were selected for further characterization. For each strain (i) an antibiogram, (ii) the phylogenetic group, (iii) plasmid replicon type, (iv) presence and identification of integrons, and (v) antibiotic resistance transfer ratios were determined. Forty-five of these strains were resistant to 5 or more antibiotics, and 6 strains were resistant to 10 or more antibiotics. Resistance was most common to ampicillin (100%), sulfamethoxazole, ciprofloxacin (82%), trimethoprim, tetracycline (74%), cefotaxime, (70%) and ceftazidime (62%). Phylogenetic groups A (62%) and B1 (26%) were most common, followed by C (8%) and E (4%). In 43 strains, more than 1 replicon type was detected, with FII (88%), FIB (70%), and I1 (48%) being the most encountered types. Forty strains, positive for integrons, all harbored a class I integron and seven of them contained an additional class II integron. No class III integrons were detected. The antibiotic resistance transfer was assessed by liquid mating experiments. The transfer ratio, expressed as the number of transconjugants per recipient, was between 10(-5) and 10(0) for cefotaxime resistance and between 10(-7) and 10(-1) for ciprofloxacin resistance. The results of the current study prove that commensal E. coli in food-production animals can be a source of multiple resistance genes and that these bacteria can easily spread their ciprofloxacin and cefotaxime resistance.201829148895
2749170.9998Culture-independent methods reveal high diversity of OXA-48-like genes in water environments. The carbapenemase OXA-48 was identified for the first time in 2001 and is now one of the greatest concerns in terms of antibiotic resistance. While many studies report clinical OXA-48-like producers, few reports refer bla(OXA-48-like) genes in environmental bacteria. The main goal of this study was to evaluate the diversity of bla(OXA-48-like) genes in aquatic systems, using culture-independent approaches. For that, environmental DNA was obtained from riverine and estuarine water and used to construct clone libraries of bla(OXA-48-like) gene polymerase chain reaction amplicons. bla(OXA-48-like) libraries from river and estuarine water DNA comprised 75 and 70 clones, respectively. Sequence analysis showed that environmental bla(OXA-48-like) genes show a broader diversity than that so far observed in clinical settings. In total, 50 new OXA-48 variants were identified as well as sequences identical to previously reported OXA-48, OXA-181, OXA-199, OXA-204 and OXA-162. Though we have no evidence that these genes were carried by bacteria that are members of the natural heterotrophic flora or bacteria that have entered this particular water environment through anthropogenic sources, these results reinforce the role of aquatic systems as antibiotic resistance reservoirs. The variants of bla(OXA-48) here described should be taken into account when designing molecular strategies for detecting this gene.201728771149
878180.9998Environmental Spread of New Delhi Metallo-β-Lactamase-1-Producing Multidrug-Resistant Bacteria in Dhaka, Bangladesh. Resistance to carbapenem antibiotics through the production of New Delhi metallo-β-lactamase-1 (NDM-1) constitutes an emerging challenge in the treatment of bacterial infections. To monitor the possible source of the spread of these organisms in Dhaka, Bangladesh, we conducted a comparative analysis of wastewater samples from hospital-adjacent areas (HAR) and from community areas (COM), as well as public tap water samples, for the occurrence and characteristics of NDM-1-producing bacteria. Of 72 HAR samples tested, 51 (71%) samples were positive for NDM-1-producing bacteria, as evidenced by phenotypic tests and the presence of the bla(NDM-1) gene, compared to 5 of 41 (12.1%) samples from COM samples (P < 0.001). All tap water samples were negative for NDM-1-producing bacteria. Klebsiella pneumoniae (44%) was the predominant bacterial species among bla(NDM-1)-positive isolates, followed by Escherichia coli (29%), Acinetobacter spp. (15%), and Enterobacter spp. (9%). These bacteria were also positive for one or more other antibiotic resistance genes, including bla(CTX-M-1) (80%), bla(CTX-M-15) (63%), bla(TEM) (76%), bla(SHV) (33%), bla(CMY-2) (16%), bla(OXA-48-like) (2%), bla(OXA-1) (53%), and bla(OXA-47-like) (60%) genes. Around 40% of the isolates contained a qnr gene, while 50% had 16S rRNA methylase genes. The majority of isolates hosted multiple plasmids, and plasmids of 30 to 50 MDa carrying bla(NDM-1) were self-transmissible. Our results highlight a number of issues related to the characteristics and source of spread of multidrug-resistant bacteria as a potential public health threat. In view of the existing practice of discharging untreated liquid waste into the environment, hospitals in Dhaka city contribute to the potential dissemination of NDM-1-producing bacteria into the community.IMPORTANCE Infections caused by carbapenemase-producing Enterobacteriaceae are extremely difficult to manage due to their marked resistance to a wide range of antibiotics. NDM-1 is the most recently described carbapenemase, and the bla(NDM-1) gene, which encodes NDM-1, is located on self-transmissible plasmids that also carry a considerable number of other antibiotic resistance genes. The present study shows a high prevalence of NDM-1-producing organisms in the wastewater samples from hospital-adjacent areas as a potential source for the spread of these organisms to community areas in Dhaka, Bangladesh. The study also examines the characteristics of the isolates and their potential to horizontally transmit the resistance determinants. The significance of our research is in identifying the mode of spread of multiple-antibiotic-resistant organisms, which will allow the development of containment measures, leading to broader impacts in reducing their spread to the community.201728526792
2746190.9998Antibiotic 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