The Beta-Lactam Resistome Expressed by Aerobic and Anaerobic Bacteria Isolated from Human Feces of Healthy Donors. - Related Documents




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236901.0000The Beta-Lactam Resistome Expressed by Aerobic and Anaerobic Bacteria Isolated from Human Feces of Healthy Donors. Antibiotic resistance is a major health problem worldwide, causing more deaths than diabetes and cancer. The dissemination of vertical and horizontal antibiotic resistance genes has been conducted for a selection of pan-resistant bacteria. Here, we test if the aerobic and anaerobic bacteria from human feces samples in health conditions are carriers of beta-lactamases genes. The samples were cultured in a brain-heart infusion medium and subcultured in blood agar in aerobic and anaerobic conditions for 24 h at 37 °C. The grown colonies were identified by their biochemical profiles. The DNA was extracted and purified by bacterial lysis using thermal shock and were used in the endpoint PCR and next generation sequencing to identify beta-lactamase genes expression (OXA, VIM, SHV, TEM, IMP, ROB, KPC, CMY, DHA, P, CFX, LAP, and BIL). The aerobic bacterias Aeromonas hydrophila, Citrobacter freundii, Proteus mirabilis, Providencia rettgeri, Serratia fonticola, Serratia liquefaciens, Enterobacter aerogenes, Escherichia coli, Klebsiella pneumoniae, Pantoea agglomerans, Enterococcus faecalis, and Enterobacter cloacae, the anaerobic bacteria: Capnocytophaga species, Bacteroides distasonis, Bifidobacterium adolescentis, Bacteroides ovatus, Bacteroides fragilis, Eubacterium species, Eubacterium aerofaciens, Peptostreptococcus anaerobius, Fusobacterium species, Bacteroides species, and Bacteroides vulgatus were isolated and identified. The results showed 49 strains resistant to beta-lactam with the expression of blaSHV (10.2%), blaTEM (100%), blaKPC (10.2%), blaCYM (14.3%), blaP (2%), blaCFX (8.2%), and blaBIL (6.1%). These data support the idea that the human enteric microbiota constitutes an important reservoir of genes for resistance to beta-lactamases and that such genes could be transferred to pathogenic bacteria.202134204872
230210.9996Antibiotic resistance and its correlation with biofilm formation and virulence genes in Klebsiella pneumoniae isolated from wounds. Klebsiella pneumoniae is the most important species of the Klebsiella genus and often causes hospital infections. These bacteria have a high resistance to most of the available drugs, which has caused concern all over the world. In this study, we investigated the antibiotic resistance profile and the ability to produce extended-spectrum beta-lactamase (ESBL) among K. pneumoniae isolates, and then we investigated the relationship between these two factors with biofilm formation and the prevalence of different virulence genes. In this study, 130 isolates of K. pneumoniae isolated from wounds were investigated. The antibiotic resistance of the isolates was evaluated by the disk diffusion method. The microtiter plate method was used to measure biofilm formation. The prevalence of virulence genes was detected by multiplex PCR. Among the examined isolates, 85.3% showed multidrug resistance. 87.6% of the isolates were ESBL-positive. Imipenem, meropenem, and fosfomycin were the most effective drugs. The ability of the isolates to produce biofilm was strong (80%), moderate (12.3%), and weak (7.6%), respectively. fimH, mrKD, entB, and tolC virulence genes were observed in all isolates. High prevalence of antibiotic resistance (especially multidrug resistance), high prevalence of ESBL-producing isolates, the ability of all isolates to biofilm formation, and the presence of fimH, mrKD, entB, and tolC virulence genes in all isolates show the importance of these factors in the pathogenesis of K. pneumoniae isolates in Iraq.202439031267
230420.9996Antimicrobial consumption and resistance in five Gram-negative bacterial species in a hospital from 2003 to 2011. BACKGROUND: The misuse of antimicrobial agents increases drug resistance in bacteria. METHODS: The correlation between antimicrobial agent consumption and related resistance in the Gram-negative bacteria Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Proteus mirabilis was analyzed during the period 2003-2011. RESULTS: Among these five bacteria, overall E. coli and K. pneumoniae were more commonly isolated from bloodstream than the other species. Regarding Enterobacteriaceae, E. coli and K. pneumoniae showed annual increases of resistance to the tested antimicrobial agents; conversely, P. mirabilis exhibited reduced resistance to cefuroxime, ceftriaxone and cefepime. In contrast to the relatively low antimicrobial resistance in P. aeruginosa, A. baumannii revealed high resistance, which was over 85% resistant rate to the tested antimicrobial agents and over 80% carbapenem resistance in 2011. E. coli, K. pneumoniae, and P. mirabilis differed in development of antimicrobial resistance after consumption of the antimicrobial agents. K. pneumoniae developed resistance to all antimicrobial groups, whereas resistance in P. mirabilis was not related to any antimicrobial consumption. P. aeruginosa developed resistance to β-lactam antimicrobials and aminoglycosides, whereas A. baumanii developed resistance to carbapenems after their use. CONCLUSION: The development of antimicrobial resistance was related to antimicrobial agents and bacterial species.201524863496
100530.9996Prevalence and Characterization of Beta-Lactam and Carbapenem-Resistant Bacteria Isolated from Organic Fresh Produce Retailed in Eastern Spain. Fresh fruits and vegetables are potential reservoirs for antimicrobial resistance determinants, but few studies have focused specifically on organic vegetables. The present study aimed to determine the presence of third-generation cephalosporin (3GC)- and carbapenem-resistant Gram-negative bacteria on fresh organic vegetables produced in the city of Valencia (Spain). Main expanded spectrum beta-lactamase (ESBL)- and carbapenemase-encoding genes were also detected in the isolates. One hundred and fifteen samples were analyzed using selective media supplemented with cefotaxime and meropenem. Resistance assays for twelve relevant antibiotics in medical use were performed using a disc diffusion test. A total of 161 isolates were tested. Overall, 33.5% presented multidrug resistance and 16.8% were resistant to all β-lactam antibiotics tested. Imipenem resistance was observed in 18% of isolates, and low resistance levels were found to ceftazidime and meropenem. Opportunistic pathogens such as Acinetobacter baumannii, Enterobacter spp., Raoultella sp., and Stenotrophomonas maltophilia were detected, all presenting high rates of resistance. PCR assays revealed bla(VIM) to be the most frequently isolated ESBL-encoding gene, followed by bla(TEM) and bla(OXA-48). These results confirm the potential of fresh vegetables to act as reservoirs for 3GC- and carbapenem-producing ARB. Further studies must be carried out to determine the impact of raw organic food on the spread of AMRs into the community.202336830297
231040.9996Molecular and Clinical Data of Antimicrobial Resistance in Microorganisms Producing Bacteremia in a Multicentric Cohort of Patients with Cancer in a Latin American Country. Patients with cancer have a higher risk of severe bacterial infections. This study aims to determine the frequency, susceptibility profiles, and resistance genes of bacterial species involved in bacteremia, as well as risk factors associated with mortality in cancer patients in Colombia. In this prospective multicenter cohort study of adult patients with cancer and bacteremia, susceptibility testing was performed and selected resistance genes were identified. A multivariate regression analysis was carried out for the identification of risk factors for mortality. In 195 patients, 206 microorganisms were isolated. Gram-negative bacteria were more frequently found, in 142 cases (68.9%): 67 Escherichia coli (32.5%), 36 Klebsiella pneumoniae (17.4%), and 21 Pseudomonas aeruginosa (10.1%), and 18 other Gram-negative isolates (8.7%). Staphylococcus aureus represented 12.4% (n = 25). Among the isolates, resistance to at least one antibiotic was identified in 63% of them. Genes coding for extended-spectrum beta-lactamases and carbapenemases, blaCTX-M and blaKPC, respectively, were commonly found. Mortality rate was 25.6% and it was lower in those with adequate empirical antibiotic treatment (22.0% vs. 45.2%, OR: 0.26, 95% CI: 0.1-0.63, in the multivariate model). In Colombia, in patients with cancer and bacteremia, bacteria have a high resistance profile to beta-lactams, with a high incidence of extended-spectrum beta-lactamases and carbapenemases. Adequate empirical treatment diminishes mortality, and empirical selection of treatment in this environment of high resistance is of key importance.202336838324
195550.9996Phenotypic & genotypic study of antimicrobial profile of bacteria isolates from environmental samples. BACKGROUND & OBJECTIVES: The resistance to antibiotics in pathogenic bacteria has increased at an alarming rate in recent years due to the indiscriminate use of antibiotics in healthcare, livestock and aquaculture. In this context, it is necessary to monitor the antibiotic resistance patterns of bacteria isolated from the environmental samples. This study was conducted to determine the phenotypic and genotypic profile of antimicrobial resistance in Gram-negative bacteria isolated from environmental samples. METHODS: Two hundred and fifty samples were collected from different sources, viz. fish and fishery products (99), livestock wastes (81) and aquaculture systems (70), in and around Mangaluru, India. Isolation, identification and antimicrobial profiling were carried out as per standard protocols. The isolates were screened for the presence of resistance genes using PCR. RESULTS: A total of 519 Gram-negative bacteria comprising Escherichia coli (116), Salmonella spp. (14), Vibrio spp. (258), Pseudomonas spp. (56), Citrobacter spp. (26) and Proteus spp. (49) were isolated and characterized from 250 samples obtained from different sources. A total of 12 antibiotics were checked for their effectiveness against the isolates. While 31.6 per cent of the isolates were sensitive to all the antibiotics used, 68.4 per cent of the isolates showed resistance to at least one of the antibiotics used. One-third of the isolates showed multidrug resistance. Maximum resistance was observed for ampicillin (43.4%), followed by nitrofurantoin (20.8%). Least resistance was seen for carbapenems and chloramphenicol. PCR profiling of the resistant isolates confirmed the presence of resistance genes corresponding to their antibiotic profile. INTERPRETATION & CONCLUSIONS: This study results showed high rate of occurrence of antimicrobial resistance and their determinants in Gram-negative bacteria isolated from different environmental sources.201931219088
204060.9996Multidrug-resistant bacteria as intestinal colonizers and evolution of intestinal colonization in healthy university students in Portugal. Multidrug-resistant bacteria have been increasingly described in healthcare institutions, however community resistance also seems to be emerging. Escherichia coli an intestinal commensal bacteria, is also a pathogen and represents an important intestinal reservoir of resistance. Our aim was the study of the intestinal colonization and of the persistence of antibiotic resistant intestinal bacteria in healthy university students of Porto, in the north of Portugal. Samples from 30 university students were collected and analysed. Two E. coli isolates were randomly obtained from each student and Gram-negative bacilli resistant to antibiotics were studied. In addition, we evaluated changes in the Gram-negative intestinal colonization of ten university students in a short period of time. Molecular characterization showed a high presence of bla (TEM) in commensal E. coli . Gram-negative bacteria with intrinsic and extrinsic resistance were isolated, namely Pseudomonas spp., Enterobacter spp. and Pantoea spp. We isolated three ESBL-producing E. coli from two students. These isolates showed bla (CTX-M) group 1 (n=1), bla (CTX-M) group 9 (n=2), bla (TEM) (n=2), bla (SHV) (n=1) and tetA (n=2) genes. Additionally, they showed specific virulence factors and conjugational transfer of antibiotic resistance and virulence genes. One Pseudomonas spp. isolate resistant to carbapenems was detected colonizing one student. Our results confirm that healthy young adults may be colonized with commensals showing clinically relevant antibiotic resistance mechanisms, creating a risk of silent spread of these bacteria in the community.202133997613
103070.9996Occurrence of extended-spectrum β-lactamase-producing bacteria in urban Clinton River habitat. OBJECTIVE: The aim of this study was to determine whether Clinton River water is contaminated with antibiotics and is a reservoir of antimicrobial-resistant bacteria. METHODS: Water samples were taken from two sites of Clinton River. Antimicrobial-resistant bacteria were enumerated on agar plates supplemented with six commonly used antibiotics. Extended-spectrum β-lactamase (ESBL)-producing bacteria were identified using a BD Phoenix™ System and by 16S rRNA gene sequencing. Antimicrobial resistance gene transfer was performed by conjugation studies and the location of genes was determined by Southern hybridisation. Virulence properties of ESBL-producing isolates were determined by assessing their biofilm-forming ability, cellular toxicity, and induction of an inflammatory response in intestinal epithelial (Caco-2) cells. RESULTS: 16S rRNA analysis of water samples showed the presence of potentially pathogenic bacteria (e.g. Shigella flexneri, Klebsiella pneumoniae, Aeromonas punctata and Pseudomonas aeruginosa). Among 64 biochemically identified bacterial isolates tested, 42% were resistant to cefotaxime, 34% to chloramphenicol, 9% to tetracycline, 11% to ciprofloxacin and 9% to gentamicin. Of 27 cefotaxime-resistant isolates, 11 (41%) were ESBL-positive and possessed either bla(CTX-M) (n=9), bla(TEM) (n=1) or bla(KPC) (n=1). Comparative analysis of ESBL gene sequences from Clinton River water bacteria showed 98-100% identity with clinical isolates. ESBL-producing isolates from Clinton River water were found to form biofilms, induced inflammatory cytokines and caused toxicity to epithelial cells. CONCLUSIONS: Clinton River water contains isolates with ESBL genes identical to clinical isolates and possessing virulence properties, thus it could be a potential reservoir in causing human infections.201930316964
230180.9996Korean Nationwide Surveillance of Antimicrobial Resistance of bacteria in 1997. Antimicrobial-resistant bacteria are known to be prevalent in tertiary-care hospitals in Korea. Twenty hospitals participated to this surveillance to determine the nationwide prevalence of resistance bacteria in 1997. Seven per cent and 26% of Escherichia coli and Klebsiella pneumoniae were resistant to 3rd-generation cephalosporin. Increased resistance rates, 19% of Acinetobacter baumannii to ampicillin/sulbactam, and 17% of Pseudomonas aeruginoa to imipenem, were noted. The resistance rate to fluoroquinolone rose to 24% in E. coli, 56% in A. baumannii and 42% in P. aeruginosa. Mean resistance rates were similar in all hospital groups: about 17% of P. aeruginosa to imipenem, 50% of Haemophilus influenzae to ampicillin, 70% of Staphylococcus aureus to methicillin, and 70% of pneumococci to penicillin. In conclusion, nosocomial pathogens and problem resistant organisms are prevalent in smaller hospitals too, indicating nosocomial spread is a significant cause of the increasing prevalence of resistant bacteria in Korea.199810097685
170990.9996High 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
2232100.9996Comparison of two DNA microarrays for detection of plasmid-mediated antimicrobial resistance and virulence factor genes in clinical isolates of Enterobacteriaceae and non-Enterobacteriaceae. A DNA microarray was developed to detect plasmid-mediated antimicrobial resistance (AR) and virulence factor (VF) genes in clinical isolates of Enterobacteriaceae and non-Enterobacteriaceae. The array was validated with the following bacterial species: Escherichiacoli (n=17); Klebsiellapneumoniae (n=3); Enterobacter spp. (n=6); Acinetobacter genospecies 3 (n=1); Acinetobacterbaumannii (n=1); Pseudomonasaeruginosa (n=2); and Stenotrophomonasmaltophilia (n=2). The AR gene profiles of these isolates were identified by polymerase chain reaction (PCR). The DNA microarray consisted of 155 and 133 AR and VF gene probes, respectively. Results were compared with the commercially available Identibac AMR-ve Array Tube. Hybridisation results indicated that there was excellent correlation between PCR and array results for AR and VF genes. Genes conferring resistance to each antibiotic class were identified by the DNA array. Unusual resistance genes were also identified, such as bla(SHV-5) in a bla(OXA-23)-positive carbapenem-resistant A. baumannii. The phylogenetic group of each E. coli isolate was verified by the array. These data demonstrate that it is possible to screen simultaneously for all important classes of mobile AR and VF genes in Enterobacteriaceae and non-Enterobacteriaceae whilst also assigning a correct phylogenetic group to E. coli isolates. Therefore, it is feasible to test clinical Gram-negative bacteria for all known AR genes and to provide important information regarding pathogenicity simultaneously.201020356716
2704110.9996Assessment of the Bacterial Pollution and Detection of Antibiotic Resistance Genes in Benin: Case of the Hydrographic Channel Complex Cotonou-Nokoué Lake. The study aims to document the level of contamination of the aquatic ecosystem of the Cotonou-Lake Nokoué canal hydrographic complex by multidrug-resistant bacteria and their resistance genes. For this purpose, water samples were taken from several points of the complex and from the sediments at the depth of the lake. Samples of several species of freshly caught fish products from the lake were also collected. Bacteriological analyses were carried out according to the AFNOR standard (NF U: 47-100). The identification of the different bacterial species isolated was then carried out using the API 20E gallery and specific biochemical tests. The antibiogram of the strains was performed according to the recommendations of the EUCAST. Molecular characterization of the identified strains was carried out by searching for resistance and virulence genes. The results obtained revealed the presence of several bacterial species in water samples and in sediment and intestine samples of fishery products with a predominance of Gram-negative bacilli. The resistance profile of Gram-negative bacilli showed a total resistance to metronidazole (100%). 23% of the strains were also resistant to ciprofloxacin, 41% to amoxicillin, and 60% to aztreonam. Of the Gram-positive cocci identified, 66% was resistant to vancomycin, 7.5% to ciprofloxacin, 71% to erythromycin, and 22% to tetracycline. Regarding the genes sought, bla (TEM) (46%), bla (SHV) (24%), and bla (CTX-M-15) (31%) were present in the genome of Gram-negative bacilli as resistance genes and fimH (41%) as virulence gene. As for Gram-positive cocci, the van B gene was completely absent. The van A was present at 6.25% in Staphylococcus aureus and mecA at 21.88 and 33.33%, respectively, in Staphylococcus aureus and coagulase-negative staphylococci strains. The high resistance of isolated bacterial strains is a matter of concern and calls for a rational use of antibiotics in order to avoid the transmission of antibiotic resistance from the environment to humans.202134285697
871120.9996Comparative De Novo and Pan-Genome Analysis of MDR Nosocomial Bacteria Isolated from Hospitals in Jeddah, Saudi Arabia. Multidrug-resistant (MDR) bacteria are one of the most serious threats to public health, and one of the most important types of MDR bacteria are those that are acquired in a hospital, known as nosocomial. This study aimed to isolate and identify MDR bacteria from selected hospitals in Jeddah and analyze their antibiotic-resistant genes. Bacteria were collected from different sources and wards of hospitals in Jeddah City. Phoenix BD was used to identify the strains and perform susceptibility testing. Identification of selected isolates showing MDR to more than three classes on antibiotics was based on 16S rRNA gene and whole genome sequencing. Genes conferring resistance were characterized using de novo and pan-genome analyses. In total, we isolated 108 bacterial strains, of which 75 (69.44%) were found to be MDR. Taxonomic identification revealed that 24 (32%) isolates were identified as Escherichia coli, 19 (25.3%) corresponded to Klebsiella pneumoniae, and 17 (22.67%) were methicillin-resistant Staphylococcus aureus (MRSA). Among the Gram-negative bacteria, K. pneumoniae isolates showed the highest resistance levels to most antibiotics. Of the Gram-positive bacteria, S. aureus (MRSA) strains were noticed to exhibit the uppermost degree of resistance to the tested antibiotics, which is higher than that observed for K. pneumoniae isolates. Taken together, our results illustrated that MDR Gram-negative bacteria are the most common cause of nosocomial infections, while MDR Gram-positive bacteria are characterized by a wider antibiotic resistance spectrum. Whole genome sequencing found the appearance of antibiotic resistance genes, including SHV, OXA, CTX-M, TEM-1, NDM-1, VIM-1, ere(A), ermA, ermB, ermC, msrA, qacA, qacB, and qacC.202337894090
1008130.9996Antimicrobial resistance of Escherichia coli, Enterobacter spp., Klebsiella pneumoniae and Enterococcus spp. isolated from the feces of giant panda. BACKGROUND: Escherichia coli, Enterobacter spp., Klebsiella pneumoniae and Enterococcus spp., common gut bacteria in giant pandas, include opportunistic pathogens. The giant panda is an endangered species, classified as vulnerable by the World Wildlife Foundation. Continuous monitoring for the emergence of antimicrobial resistance (AMR) among bacterial isolates from giant pandas is vital not only for their protection but also for public health. RESULTS: A total of 166 E. coli, 68 Enterobacter spp., 116 K. pneumoniae and 117 Enterococcus spp. isolates were collected from fecal samples of 166 giant pandas. In the antimicrobial susceptibility tests, 144 E. coli isolates, 66 Enterobacter spp. isolates, 110 K. pneumoniae isolates and 43 Enterococcus spp. isolates were resistant to at least one antimicrobial. The resistant isolates carried antimicrobial resistance genes (ARGs), including sul3, bla(TEM), bla(SHV) and tetA. The differences in the prevalence of the bla types implied that the genetic basis for β-lactam resistance among the E. coli, Enterobacter spp. and K. pneumoniae isolates was different. The strain K. pneumoniae K85 that was resistant to sixteen antimicrobials was selected for whole genome sequencing. The genome contained Col440I, IncFIB(K) and IncFII(K) plasmids and altogether 258 ARGs were predicted in the genome; 179 of the predicted ARGs were efflux pump genes. The genetic environment of the β-lactamase genes bla(CTX-M-3) and bla(TEM-1) in the K. pneumoniae K85 genome was relatively similar to those in other sequenced K. pneumoniae genomes. In comparing the giant panda age groups, the differences in the resistance rates among E. coli, K. pneumoniae and Enterobacter spp. isolates suggested that the infections in giant pandas of different age should be treated differently. CONCLUSIONS: Antimicrobial resistance was prevalent in the bacterial isolates from the giant pandas, implying that the gut bacteria may pose serious health risks for captive giant pandas. The resistance genes in the genome of K. pneumoniae K85 were associated with insertion sequences and integron-integrase genes, implying a potential for the further spread of the antimicrobial resistance.202235421931
2034140.9996Multidrug-resistant Klebsiella pneumoniae isolated from farm environments and retail products in Oklahoma. Multidrug-resistant enteric bacteria were isolated from turkey, cattle, and chicken farms and retail meat products in Oklahoma. Among the isolated species, multidrug-resistant Klebsiella pneumoniae was prevalently isolated from most of the collected samples. Therefore, a total of 132 isolates of K. pneumoniae were characterized to understand their potential roles in the dissemination of antibiotic-resistance genes in the food chains. Multidrug-resistant K. pneumoniae was most frequently recovered from a turkey farm and ground turkey products among the tested samples. All isolates were resistant to ampicillin, tetracycline, streptomycin, gentamycin, and kanamycin. Class 1 integrons located in plasmids were identified as a common carrier of the aadA1 gene, encoding resistance to streptomycin and spectinomycin. Production of beta-lactamase in the K. pneumoniae isolates played a major role in the resistance to beta-lactam agents. Most isolates (96%) possessed bla(SHV1). Five strains were able to express both SHV-11 (pI 6.2) and TEM-1 (pI 5.2) beta-lactamase. Transfer of these antibiotic-resistance genes to Escherichia coli was demonstrated by transconjugation. The bacterial genomic DNA restriction patterns by pulsed-field gel electrophoresis showed that the same clones of multidrug-resistant K. pneumoniae remained in feathers, feed, feces, and drinking water in turkey environments, indicating the possible dissemination of antibiotic-resistance genes in the ecosystem and cross-contamination of antibiotic-resistant bacteria during processing and distribution of products.200516245702
1032150.9996Molecular 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
851160.9996Looking for ESKAPE Bacteria: Occurrence and Phenotypic Antimicrobial Resistance Profiles in Wild Birds from Northern and Central Italy Sites. BACKGROUND/OBJECTIVES: Antimicrobial resistance is a critical global health challenge. Among resistant pathogens, the group of bacteria collectively referred to as ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) is of particular concern due to their ability to evade multiple classes of antimicrobials. This study aimed to investigate the occurrence and resistance patterns of ESKAPE bacteria in wild birds from Northern and Central Italy sites, and to assess the presence of other bacteria of public health relevance. METHODS: Cloacal swabs were collected from 141 wild birds. Samples were processed on selective and differential media, and bacterial identification was performed using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry. Antimicrobial susceptibility was evaluated through Minimum Inhibitory Concentration assays and interpreted according to international guidelines. RESULTS: Thirty-seven isolates belonging to the ESKAPE group were identified: E. faecium (n = 10), K. pneumoniae (n = 9), P. aeruginosa (n = 8), Enterobacter spp. (n = 7), S. aureus (n = 2), and A. baumannii (n = 1). Multidrug-resistant isolates were observed among K. pneumoniae and Enterobacter hormaechei. Escherichia coli, although not included in the ESKAPE group, was frequently detected and often co-isolated with clinically relevant bacteria, highlighting its potential role as a reservoir of resistance genes. CONCLUSIONS: Wild birds can harbor resistant bacteria of clinical importance, including multidrug-resistant ESKAPE species. Their presence in avian populations underscores the role of wildlife in the environmental dissemination of antimicrobial resistance, with implications for both animal and human health.202541148717
1713170.9996Conjugative plasmidic AmpC detected in Escherichia coli, Proteus mirabilis and Klebsiella pneumoniae human clinical isolates from Portugal. AmpC is a type of β-lactamase enzyme produced by bacteria; these enzymes are classified in Class C and Group 1, and these confer resistance to cephamycin. Enterobacterales producing AmpC are reported worldwide and have great clinical importance due to therapeutic restriction and epidemiological importance once the easy dissemination by plasmidic genes to other bacteria is a real threat. These genes are naturally found in some enterobacteria as Enterobacter cloacae, Morganella morganii, and Citrobacter freundii, but other species have demonstrated similar resistance phenotype of AmpC production. Genes carried in plasmids have been described in these species conferring resistance to cefoxitin and causing therapeutic failure in some bacterial infections. This work detected and described five clinical strains of Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae that presented plasmid ampC (pAmpC) isolated from the north of Portugal collected in 2009. AmpC production was confirmed by inhibition of the enzyme by cloxacillin and boronic acid in agar diffusion tests. Also, PCR (polymerase chain reaction) was performed for the detection of gene universal to AmpC, bla(ampC), and others to AmpC group: bla(ACC), bla(CIT), bla(CMY), bla(DHA), and bla(EBC). The conjugation in liquid medium for 24 h was realized to determine if gene is localized in chromosome or plasmid. The isolates and their conjugants showed phenotypic characteristics and bla(CMY) and bla(CIT) were detected by PCR corroborating the AmpC characteristics observed in these bacteria. Confirmation of transfer of plasmid containing genes encoding AmpC is of high epidemiological relevance to the hospital studied and demonstrated the importance of AmpC surveillance and studies in hospital and community environments in order to choose the appropriate therapy for bacterial infections.202032740783
1035180.9996Multidrug resistance and transferability of blaCTX-M among extended-spectrum β-lactamase-producing enteric bacteria in biofilm. This study aimed to investigate the occurrence of biofilm-forming extended-spectrum β-lactamase (ESBL)-producing enteric bacteria in hospital wastewater and to evaluate their antibiotic resistance behaviour and transferability of the plasmid-encoded blaCTX-M gene in biofilm. ESBL production was confirmed using the combined disc test and Etest. Amplification of blaCTX-M was performed by PCR. Antibiotic susceptibility was evaluated using the disc diffusion assay and broth dilution method. Transfer of blaCTX-M in planktonic and biofilm state was performed by broth mating and filter mating experiments, respectively. Among 110 enteric bacteria, 24 (21.8%) isolates belonging to Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae were found to produce ESBL and formed varying levels of biofilm in vitro. Presence of blaCTX-M was detected in 18 (75%) ESBL-producing isolates. A many fold increase in resistance to antibiotics was observed in biofilm. Among ESBL-producers, seven isolates could transfer the blaCTX-M gene by conjugation, with transfer frequencies ranging from 2.22×10(-4) to 7.14×10(-2) transconjugants/recipient cell in the planktonic state and from 3.04×10(-3) to 9.15×10(-1) in biofilm. The transfer frequency of blaCTX-M was significantly higher in biofilm compared with the planktonic state, and co-transfer of ciprofloxacin resistance was also detected in five isolates. This study demonstrates that biofilm-forming ESBL-producing enteric bacteria with a greater transfer frequency of resistance genes will lead to frequent dissemination of β-lactam and fluoroquinolone resistance genes in environmental settings. The emergence and spread of such multidrug resistance is a serious threat to animal and public health.201627530857
1621190.9996Antibiotic Resistance and Virulence Profiles of Escherichia coli Strains Isolated from Wild Birds in Poland. Wild animals are increasingly reported as carriers of antibiotic-resistant and pathogenic bacteria including Enterobacteriaceae. However, the role of free-living birds as reservoirs for potentially dangerous microbes is not yet thoroughly understood. In our work, we examined Escherichia coli strains from wild birds in Poland in relation to their antimicrobial agents susceptibility, virulence and phylogenetic affiliation. Identification of E. coli was performed using MALDI-TOF mass spectrometry. The antibiotic susceptibility of the isolates was determined by the broth microdilution method, and resistance and virulence genes were detected by PCR. E. coli bacteria were isolated from 32 of 34 samples. The strains were most often classified into phylogenetic groups B1 (50%) and A (25%). Resistance to tetracycline (50%), ciprofloxacin (46.8%), gentamicin (34.3%) and ampicillin (28.1%) was most frequently reported, and as many as 31.2% of E. coli isolates exhibited a multidrug resistance phenotype. Among resistance genes, sul2 (31.2% of isolates) and bla(TEM) (28.1%) were identified most frequently, while irp-2 (31.2%) and ompT (28.1%) were the most common virulence-associated genes. Five strains were included in the APEC group. The study indicates that wild birds can be carriers of potentially dangerous E. coli strains and vectors for the spread of resistant bacteria and resistance determinants in the environment.202134451523