Dynamics of Antimicrobial Susceptibility and Risk Factors Associated with Infections Caused by Colistin-Resistant Bacteria: A Study from the Northern Region of Haryana, India. - Related Documents




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85401.0000Dynamics of Antimicrobial Susceptibility and Risk Factors Associated with Infections Caused by Colistin-Resistant Bacteria: A Study from the Northern Region of Haryana, India. Antimicrobial resistance poses a significant threat to global health, with colistin as a last-resort antibiotic against multidrug-resistant (MDR) microorganisms. The present study aimed to investigate the dynamics of antimicrobial susceptibility patterns and risk factors associated with infections caused by colistin-resistant bacteria in the Northern region of Haryana, India. Clinical samples (n = 12,652) collected from a single hospital in Haryana were subjected to microbiological analysis for five months. Among the total samples (n = 12,652) processed, 24% (n = 3,061) showed growth of pathogenic bacteria. Within the Gram-negative isolates, 56% (n = 1,242) were non-MDR, while 44% (n = 995) were MDR. Among MDR isolates (n = 995), 6% (n = 57) showed resistance to colistin. Notably, Pseudomonas spp. (12%, n = 19) and Acinetobacter spp. (11%, n = 8) demonstrated the highest resistance to colistin, followed by Klebsiella spp. (5%, n = 13), Escherichia coli (3%, n = 16), and Citrobacter freundii (1%, n = 1), respectively. The study revealed significant associations between the level of education (demographic variable) and the occurrence of colistin resistance. Prolonged hospital stays (> 5 days) and specific comorbidities, including diabetes (p < 0.01) and chronic obstructive pulmonary disease (p < 0.01), were identified as risk factors for colistin-resistant infections. Importantly, none of the colistin-resistant bacteria harbored mcr genes, suggesting alternative resistance mechanisms. Antibiotic sensitivity analysis indicated promising efficacy of antibiotics such as amikacin and gentamicin against colistin-resistant strains, though with variations across bacterial species. In summary, the study emphasizes the urgent need for enhanced surveillance, infection control protocols, and antimicrobial stewardship programs in healthcare settings to minimize the dissemination of MDR and colistin-resistant bacteria.202540146792
87710.9998Drug 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
85320.9998Nosocomial Pneumonia in Georgia: A Focus on Gram-Positive Bacteria and Antimicrobial Resistance. Nosocomial pneumonia represents a significant clinical challenge worldwide, and in Georgia, the burden of this healthcare-associated infection is a growing concern. This study investigates the role of gram-positive bacteria in nosocomial pneumonia cases, focusing on their prevalence, antimicrobial resistance patterns, and associated risk factors. A retrospective analysis of 484 clinical samples collected from 397 patients between May 2022 and September 2024 highlights the distribution of pathogens, with a particular emphasis on Staphylococcus aureus and Streptococcus pneumoniae. Among gram-positive pathogens, Staphylococcus aureus was the most prevalent, accounting for 103 cases (21.3%), followed by Streptococcus pneumoniae with 45 cases (9.3%). The study identifies alarming rates of antimicrobial resistance among gram-positive pathogens. Staphylococcus aureus isolates demonstrated universal penicillinase production (103/103, 100%) and high levels of mecA-mediated methicillin resistance (89/103, 86.4%) and erm-mediated macrolide resistance (74/103, 71.8%). Additionally, notable resistance was observed to tetracycline (93/103, 90.3%), aminoglycosides (31/103, 30.1%), and fluoroquinolones (41/103, 39.8%). Streptococcus pneumoniae isolates exhibited universal penicillinase production (45/45, 100%), with complete beta-lactam resistance found in 42 isolates (42/45, 93.3%), mediated through mutations in the pbp1a, pbp2x, and pbp2b genes. Furthermore, erm(B)-mediated macrolide resistance was observed in 37 isolates (37/45, 82.2%), tetM-mediated tetracycline resistance in 37 isolates (37/45, 82.2%), and fluoroquinolone resistance in 13 isolates (13/45, 28.9%). One isolate of each pathogen demonstrated vancomycin resistance, underscoring the emergence of multidrug-resistant (MDR) strains. The study underscores the need for stringent infection control measures and rational antibiotic stewardship to mitigate the impact of resistant gram-positive pathogens in Georgian healthcare settings. The findings also stress the importance of continuous surveillance to monitor resistance trends and guide empirical therapy. By exploring the resistance mechanisms and prevalence of gram-positive bacteria in nosocomial pneumonia, this research contributes to a deeper understanding of the local epidemiology and highlights actionable insights for improving patient outcomes.202539974234
100430.9998Hospital Wastes as Potential Sources for Multi-Drug-Resistant ESBL-Producing Bacteria at a Tertiary Hospital in Ethiopia. The hospital environment is increasingly becoming an important reservoir for multi-drug-resistant (MDR) Gram-negative bacteria, posing serious challenges to efforts to combat antimicrobial resistance (AMR). This study aimed to investigate the role of hospital waste as a potential source of MDR ESBL-producing bacteria. Samples were collected from multiple sources within a hospital and its vicinity, including surface swabs, houseflies, and sewage samples. The samples were subsequently processed in a microbiology laboratory to identify potential pathogenic bacteria and confirmed using MALDI-TOF MS. Bacteria were isolated from 87% of samples, with the predominant isolates being E. coli (30.5%), Klebsiella spp. (12.4%), Providencia spp. (12.4%), and Proteus spp. (11.9%). According to the double disc synergy test (DDST) analysis, nearly half (49.2%) of the bacteria were identified as ESBL producers. However, despite exhibiting complete resistance to beta-lactam antibiotics, 11.8% of them did not test positive for ESBL production. The characterization of E. coli revealed that 30.6% and 5.6% of them carried blaCTX-M group 1 type-15 and blaNDM genes, respectively. This finding emphasizes the importance of proper hospital sanitation and waste management practices to mitigate the spread of AMR within the healthcare setting and safeguard the health of both patients and the wider community.202438667050
86940.9998The Prevalence of Antibiotic Resistance Phenotypes and Genotypes in Multidrug-Resistant Bacterial Isolates from the Academic Hospital of Jaén, Spain. The heterogenicity of antimicrobial resistance genes described in clinically significant bacterial isolates and their potential role in reducing the efficacy of classically effective antibiotics pose a major challenge for global healthcare, especially in infections caused by Gram-negative bacteria. We analyzed 112 multidrug-resistant (MDR) isolates from clinical samples in order to detect high resistance profiles, both phenotypically and genotypically, among four Gram-negative genera (Acinetobacter, Escherichia, Klebsiella, and Pseudomonas). We found that 9.8% of the total selected isolates were classified as extensively drug-resistant (XDR) (six isolates identified as A. baumannii and five among P. pneumoniae isolates). All other isolates were classified as MDR. Almost 100% of the isolates showed positive results for bla(OXA-23) and bla(NDM-1) genes among the A. baumannii samples, one resistance gene (bla(CTX-M)) among E. coli, and two genetic determinants (bla(CTX-M) and aac(6')-Ib) among Klebsiella. In contrast, P. aeruginosa showed just one high-frequency antibiotic resistance gene (dfrA), which was present in 68.42% of the isolates studied. We also describe positive associations between ampicillin and cefotaxime resistance in A. baumannii and the presence of bla(VEB) and bla(GES) genes, as well as between the aztreonam resistance phenotype and the presence of bla(GES) gene in E. coli. These data may be useful in achieving a better control of infection strategies and antibiotic management in clinical scenarios where these multidrug-resistant Gram-negative pathogens cause higher morbidity and mortality.202438786157
86150.9998The Prevalence Rates of Colistin Resistance Among Third-Generation Cephalosporin-Resistant E. coli Isolates From Thai Patients. Drug-resistant infections, such as colistin resistance, are reportedly increasing due to the inappropriate use of antibiotics, lack of good control, and the use of excessive quantities of antibiotics. Colistin resistance has been observed in bacteria of the order Enterobacterales exhibiting resistance to third-generation cephalosporins or carbapenems. Currently, the prevalence of colistin resistance in third-generation cephalosporin-resistant E. coli obtained from patients at Nopparat Rajathanee Hospital, Thailand, in 2023 was determined by broth microdilution. Among 343 isolates, 1.45% (95% CI: 0.19%-2.73%, n = 5/343) exhibited a minimum inhibitory concentration (MIC) of colistin between 4 and 8 μg/mL, indicating colistin-resistant E. coli. Nevertheless, five isolates were positive for resistant genes by multiplex PCR: two isolates for mcr-1, two isolates for mcr-3, and one isolate for both mcr-1 and mcr-3. This study reveals crucial data on resistance genes, informing surveillance of antibiotic resistance, treatment decisions, and public health initiatives to combat resistant bacteria.202541170286
231060.9998Molecular 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
168070.9998Emergence of carbapenem resistant gram-negative pathogens with high rate of colistin resistance in Egypt: A cross sectional study to assess resistance trends during the COVID-19 pandemic. The current study investigated the temporal phenotypic and genotypic antimicrobial resistance (AMR) trends among multi-drug resistant and carbapenem-resistant Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa recovered from Egyptian clinical settings between 2020 and 2021. Bacterial identification and antimicrobial sensitivity of 111 clinical isolates against a panel of antibiotics were performed. Molecular screening for antibiotic resistance determinants along with integrons and associated gene cassettes was implemented. An alarming rate (98.2%) of these isolates were found to be phenotypically resistant to carbapenem. Although 23.9 % K. pneumoniae isolates were phenotypically resistant to colistin, no mobile colistin resistance (mcr) genes were detected. Among carbapenem-resistant isolates, bla(NDM) and bla(OXA-48)-like were the most prevalent genetic determinants and were significantly overrepresented among K. pneumoniae. Furthermore, 84.78% of K. pneumoniae isolates co-produced these two carbapenemase genes. The plasmid-mediated quinolone resistance genes (qnrS and qnrB) were detected among the bacterial species and were significantly more prevalent among K. pneumoniae. Moreover, Class 1 integron was detected in 82% of the bacterial isolates. This study alarmingly reveals elevated resistance to last-resort antibiotics such as carbapenems as well as colistin which impose a considerable burden in the health care settings in Egypt. Our future work will implement high throughput sequencing-based antimicrobial resistance surveillance analysis for characterization of novel AMR determinants. This information could be applied as a step forward to establish a robust antibiotic stewardship program in Egyptian clinical settings, thereby addressing the rising challenges of AMR.202438494251
93180.9998Epidemiological characteristics and antimicrobial susceptibility among carbapenem-resistant non-fermenting bacteria in Brazil. INTRODUCTION: Non-fermenting Gram-negative bacteria such as Pseudomonas aeruginosa and Acinetobacter baumannii are widespread in the environment and are increasingly associated with nosocomial infections. Extensive and indiscriminate use of antibiotics in hospitals has contributed to an increased number of infections caused by these microorganisms, that are resistant to a wide variety of antimicrobials, including β-lactams. This study aimed to isolate and identify carbapenem-resistant Acinetobacter spp. and P. aeruginosa from hospitalized patients, to determine their antimicrobial susceptibility patterns and to screen for blaOXA-23, blaOXA-24, blaOXA-51, blaOXA-58, and blaOXA-143 genes among the isolated bacteria. METHODOLOGY: Antimicrobial resistance patterns were performed using the disk-diffusion method. Genetic markers related to carbapenem resistance were screened by polymerase chain reaction. RESULTS: Carbapenem-resistant Acinetobacter spp. (n = 44) and P. aeruginosa (n = 28) samples were isolated from patients admitted to a tertiary hospital. Polymyxin B was the only effective drug for all isolates. Considering the oxacillinase gene screening, genetic markers were observed only in Acinetobacter isolates. The most frequent genotype observed was blaOXA-23+/blaOXA-51+ (45.5%), followed by blaOXA-51+/blaOXA-143+ (41%). The oxacillinase genes blaOXA-24 and blaOXA-58 were not detected. High mortality rates (> 70%) were observed. CONCLUSIONS: The data suggest the need for rational use of antimicrobials associated with early diagnosis of multidrug-resistant bacteria, especially considering non-fermenting Gram-negative rods, which are widespread in hospitals. The findings of blaoxa-51(-) strains suggest the occurrence and spread of non-A. baumannii species throughout our hospitals. Effective implementation of surveillance programs in hospitals is needed to reduce infectious and resistant intra- and inter-species bacteria.201627367001
230990.9998Antimicrobial Resistance Patterns of Pathogens Isolated from Patients with Wound Infection at a Teaching Hospital in Vietnam. PURPOSE: At a teaching Hospital in Vietnam, the persistently high incidence of diagnosed wound infection poses ongoing challenges to treatment. This study seeks to explore the causative agents of wound infection and their antimicrobial and multidrug resistance patterns. METHODS: A cross-sectional study was conducted at the Department of Microbiology, Military Hospital 103, Vietnam. Data on microorganisms that caused wound infection and their antimicrobial resistance patterns was recorded from hospitalized patients from 2014 to 2021. Using the chi-square test, we analyzed the initial isolation from wound infection specimens collected from individual patients. RESULTS: Over a third (34.9%) of wound infection samples yielded bacterial cultures. Staphylococcus aureus was the most prevalent bacteria, followed by Pseudomonas aeruginosa. Worryingly high resistance rates were observed for several antibiotics, particularly among Gram-negative bacteria. Ampicillin displayed the highest resistance (91.9%), while colistin and ertapenem remained the most effective. In Gram-positive bacteria, glycopeptides like teicoplanin and vancomycin (0% and 3.3% resistance, respectively) were most effective, but their use was limited. Clindamycin and tetracycline showed decreasing effectiveness. Resistance rates differed between surgical and non-surgical wards, highlighting the complex dynamics of antimicrobial resistance within hospitals. Multidrug resistance (MDR) was substantial, with Gram-negative bacteria exhibiting a 63.6% MDR rate. Acinetobacter baumannii showed the highest MDR rate (88.0%). CONCLUSION: This study investigated wound infection characteristics, antibiotic resistance patterns of common bacteria, and variations by hospital ward. S. aureus was the most prevalent bacteria, and concerning resistance rates were observed, particularly among Gram-negative bacteria. These findings highlight the prevalence of multidrug resistance in wound infections, emphasizing the importance of infection control measures and judicious antibiotic use.202439139624
1142100.9998Virulence Determinants and Plasmid-Mediated Colistin Resistance mcr Genes in Gram-Negative Bacteria Isolated From Bovine Milk. A major increase of bacterial resistance to colistin, a last-resort treatment for severe infections, was observed globally. Using colistin in livestock rearing is believed to be the ground of mobilized colistin resistance (mcr) gene circulation and is of crucial concern to public health. This study aimed to determine the frequency and virulence characteristics of colistin-resistant Gram-negative bacteria from the milk of mastitic cows and raw unpasteurized milk in Egypt. One hundred and seventeen strains belonging to Enterobacteriaceae (n = 90), Pseudomonas aeruginosa (n = 10), and Aeromonas hydrophila (n = 17) were screened for colistin resistance by antimicrobial susceptibility testing. The genetic characteristics of colistin-resistant strains were investigated for mcr-1-9 genes, phylogenetic groups, and virulence genes. Moreover, we evaluated four commonly used biocides in dairy farms for teat disinfection toward colistin-resistant strains. Multidrug-resistant (MDR) and extensive drug-resistant (XDR) phenotypes were detected in 82.91% (97/117) and 3.42% (4/117) of the isolates, respectively. Of the 117 tested isolates, 61 (52.14%) were colistin resistant (MIC >2 mg/L), distributed as 24/70 (34.29%) from clinical mastitis, 10/11 (90.91%) from subclinical mastitis, and 27/36 (75%) from raw milk. Of these 61 colistin-resistant isolates, 47 (19 from clinical mastitis, 8 from subclinical mastitis, and 20 from raw milk) harbored plasmid-borne mcr genes. The mcr-1 gene was identified in 31.91%, mcr-2 in 29.79%, mcr-3 in 34.04%, and each of mcr-4 and mcr-7 in 2.13% of the colistin-resistant isolates. Among these isolates, 42.55% (20/47) were E. coli, 21.28% (10/47) A. hydrophila, 19.12% (9/47) K. pneumoniae, and 17.02% (8/47) P. aeruginosa. This is the first report of mcr-3 and mcr-7 in P. aeruginosa. Conjugation experiments using the broth-mating technique showed successful transfer of colistin resistance to E. coli J53-recipient strain. Different combinations of virulence genes were observed among colistin-resistant isolates with almost all isolates harboring genes. Hydrogen peroxide has the best efficiency against all bacterial isolates even at a low concentration (10%). In conclusion, the dissemination of mobile colistin resistance mcr gene and its variants between MDR- and XDR-virulent Gram-negative isolates from dairy cattle confirms the spread of mcr genes at all levels; animals, humans, and environmental, and heralds the penetration of the last-resort antimicrobial against MDR bacteria. Consequently, a decision to ban colistin in food animals is urgently required to fight XDR and MDR bacteria.202134888259
1146110.9998Molecular detection and prevalence of colistin-resistant Escherichia coli in poultry and humans: a one health perspective. Multidrug-resistant (MDR) bacteria significantly threaten humans and animals worldwide. Colistin is the last resort of antibiotics against gram-negative bacterial infections. Its irrational use in poultry is a major factor in transmitting MDR bacteria to humans. The present study investigated the risk factors, prevalence, and molecular detection of colistin resistance associated with poultry and humans. A total of (n = 140) cloacal swabs from chickens and human stool samples (n = 140) were processed to identify E. coli using conventional methods, followed by genotypic confirmation. Phenotypic and genotypic confirmation of antibiotic resistance genes qnrA, blaTEM, tetA, aadA, and mcr genes was performed on these E. coli isolates. These isolates were confirmed at 69.3% and 62.8% in chickens and humans, respectively. Limited education and poor hygiene significantly increased the infection rate (p = 0.0001). The E. coli isolates from commercial poultry showed 100% resistance to amoxicillin/clavulanic acid, 98.9% to ampicillin, and 93.8% to tetracycline. The E. coli isolates from humans exhibited 90% resistance to ciprofloxacin, 88% to ampicillin, and 85% to ceftriaxone. Among these, MDR E. coli isolates of both commercial poultry and humans, colistin resistance was found in 78.6% and 48.1%, respectively. Genotypic confirmation of mcr genes such as mcr-1 (42%), mcr-2 (19.6%), mcr-3 (15.1%), mcr-4 (7.6%), and mcr-5 (4.5%) in commercial poultry. However, only the mcr-1 (15.6%) gene was found in human isolates. The current study findings highlight the prevalence of mcr genes in E. coli, potentially contributing to broader antibiotic resistance concerns.202540956559
859120.9997Analysis of mcr family of colistin resistance genes in Gram-negative isolates from a tertiary care hospital in India. AIM: Colistin serves as the drug of last resort for combating numerous multidrug-resistant (MDR) Gram-negative infections. Its efficacy is hampered by the prevalent issue of colistin resistance, which severely limits treatment options for critically ill patients. Identifying resistance genes is crucial for controlling resistance spread, with horizontal gene transfer being the primary mechanism among bacteria. This study aimed to assess the prevalence of plasmid-mediated mcr genes associated with colistin resistance in Gram-negative bacteria, utilizing both genotypic and phenotypic tests. METHODS AND RESULTS: The clinical isolates (n = 913) were obtained from a tertiary care center in Chennai, India. Colistin resistance was seen among Gram-negative isolates. These strains underwent screening for mcr-1, mcr-3, mcr-4, and mcr-5 genes via conventional PCR. Additionally, mcr-positive isolates were confirmed through Sanger sequencing and phenotypic testing. The bacterial isolates predominantly comprised Klebsiella pneumoniae (62.43%), Escherichia coli (19.71%), Pseudomonas aeruginosa (10.73%), and Acinetobacter baumannii (4.81%), along with other species. All isolates exhibited multidrug resistance to three or more antibiotic classes. Colistin resistance, determined via broth microdilution (BMD) using CLSI guidelines, was observed in 13.08% of the isolates studied. Notably, mcr-5 was detected in K. pneumoniae in PCR, despite its absence in Sanger sequencing and phenotypic tests (including the combined-disk test, colistin MIC in the presence of EDTA, and Zeta potential assays). This finding underscores the importance of employing multiple diagnostic approaches to accurately identify colistin resistance mechanisms.202438986507
1954130.9997Detection of multidrug resistant environmental isolates of acinetobacter and Stenotrophomonas maltophilia: a possible threat for community acquired infections? Acinetobacter spp. and Stenotrophomonas maltophilia are bacteria commonly associated with infections at the clinical settings. Reports of infections caused by environmental isolates are rare. Therefore, this study focused on determination of the antibiotic resistance patterns, antibiotic resistance genes, efflux pumps and virulence signatures of Acinetobacter spp. and S. maltophilia recovered from river water, plant rhizosphere and river sediment samples. The isolates were identified and confirmed using biochemical tests and PCR. The antimicrobial resistance profiles of the isolates were determined using Kirby Bauer disk diffusion assay and presence of antibiotic resistance and virulence genes were detected using PCR. S. maltophilia was more frequent in plant rhizosphere and sediment samples than the water samples. Acinetobacter spp. were mostly resistant to trimethoprim-sulfamethoxazole (96% of isolates), followed by polymyxin b (86%), cefixime (54%), colistin (42%), ampicillin (35%) and meropenem (19%). The S. maltophilia isolates displayed total resistance (100%) to trimethoprim- sulfamethoxazole, meropenem, imipenem, ampicillin and cefixime, while 80% of the isolates were resistant to ceftazidime. Acinetobacter spp. contained different antibiotic resistance genes such as sul1 (24% of isolates), sul2 (29%), blaOXA 23/51 (21%) and blaTEM (29%), while S. maltophilia harbored sul1 (8%) and blaTEM (20%). Additionally, efflux pump genes were present in all S. maltophilia isolates. The presence of multidrug resistant Acinetobacter spp. and Stenotrophomonas maltophilia in surface water raises concerns for community-acquired infections as this water is directly been used by the community for various purposes. Therefore, there is the need to institute measures aimed at reducing the risks of these infections and the resulting burden this may have on the health care system within the study area.202133378222
2306140.9997Resistance to nitrofurantoin is an indicator of extensive drug-resistant (XDR) Enterobacteriaceae. Introduction. Nitrofurantoin is one of the preferred antibiotics in the treatment of uropathogenic multidrug-resistant (MDR) infections. However, resistance to nitrofurantoin in extensively drug-resistant (XDR) bacteria has severely limited the treatment options.Gap statement. Information related to co-resistance or collateral sensitivity (CS) with reference to nitrofurantoin resistant bacteria is limited.Aim. To study the potential of nitrofurantoin resistance as an indicator of the XDR phenotype in Enterobacteriaceae.Methods. One hundred (45 nitrofurantoin-resistant, 21 intermediately resistant and 34 nitrofurantoin-susceptible) Enterobacteriaceae were analysed in this study. Antibiotic susceptibility testing (AST) against nitrofurantoin and 17 other antimicrobial agents across eight different classes was performed by using the Vitek 2.0 system. The isolates were screened for the prevalence of acquired antimicrobial resistance (AMR) and efflux pump genes by PCR.Results. In total, 51 % of nitrofurantoin-resistant and 28 % of intermediately nitrofurantoin resistant isolates exhibited XDR characteristics, while only 3 % of nitrofurantoin-sensitive isolates were XDR (P=0.0001). Significant co-resistance was observed between nitrofurantoin and other tested antibiotics (β-lactam, cephalosporin, carbapenem, aminoglycoside and tetracycline). Further, the prevalence of AMR and efflux pump genes was higher in the nitrofurantoin-resistant strains compared to the susceptible isolates. A strong association was observed between nitrofurantoin resistance and the presence of bla (PER-1), bla (NDM-1), bla (OXA-48), ant(2) and oqxA-oqxB genes. Tigecycline (84 %) and colistin (95 %) were the only antibiotics to which the majority of the isolates were susceptible.Conclusion. Nitrofurantoin resistance could be an indicator of the XDR phenotype among Enterobacteriaceae, harbouring multiple AMR and efflux pump genes. Tigecycline and colistin are the only antibiotics that could be used in the treatment of such XDR infections. A deeper understanding of the co-resistance mechanisms in XDR pathogens and prescription of AST-based appropriate combination therapy may help mitigate this problem.202133830906
1034150.9997Detection of metallo-beta-lactamase-producing genes bla(SPM) and bla(NDM) in Pseudomonas aeruginosa isolated from wastewater in Southern Brazil. Pseudomonas aeruginosa is commonly associated with the ability to acquire antimicrobial resistance. The surveillance of resistance genes in various environmental matrices has gained prominence in recent years, being seen as a potential threat to public health. The objective of this study was to investigate genes encoding metallo-beta-lactamases (MBLs), which confer resistance to carbapenems, in wastewater. Fifteen isolates of P. aeruginosa were collected for five months from samples obtained from a municipal wastewater treatment plant in Rio Grande do Sul. These isolates were subjected to disk diffusion testing using 10 different antimicrobials. Phenotypic enzymatic tests for MBLs were conducted, and positive isolates underwent DNA extraction and gene detection using the polymerase chain reaction. The resistance rate to ceftazidime was 100%, cefepime 73.3%, piperacillin-tazobactam 66.67%, imipenem 53.30%, levofloxacin 46.67%, tobramycin 40%, and ciprofloxacin and amikacin 13.33%. Both meropenem and aztreonam resistances were rare accounting for 6.60% of the tested isolates. Among these isolates, 20% were classified as multidrug-resistant and were found to carry the bla(NDM) and bla(SPM) genes. The results suggest that evaluating resistance genes in bacteria from urban raw sewage can provide data that assist in surveillance, as this environment can stimulate increased bacterial resistance.202438678422
1679160.9997Analysis of ESKAPE pathogens in clinical isolates in a tertiary care hospital in China from 2018 to 2023. The widespread use of antimicrobial agents correlated with the increasing incidence of nosocomial infections and bacterial antibiotic resistance. These have become major challenges in the prevention and control of hospital-acquired infections worldwide. The aims of this study were to analyze the distribution and characteristics of ESKAPE pathogenic bacteria and their antibiotic resistance profile among clinical isolates from a tertiary hospital in China from 2018 to 2023. The results showed that a total of 20,472 non-duplicated pathogenic bacteria were isolated from clinical specimens in this hospital between 2018 and 2023, of which the top five pathogenic bacteria were Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Acinetobacter baumannii. In case of E. coli the main detected resistance genes were blaCTX-M, blaTEM and blaOXA. K. pneumoniae mainly carried blaOXA, blaKPC and blaNDM genes. P. aeruginosa was mainly positive for blaOXA, AmpC type beta-lactamases and blaVIM genes. A. baumannii mainly carried ArmA, blaTEM and cas3 genes. S. aureus was mainly positive for mecA, erm(C) and erm(A) genes. In this study, we have found that the antibiotic resistance of common pathogens from clinical isolates in a tertiary hospital in China in the past 6 years is severe, and A. baumannii was particularly a prominent pathogen. There is an urgent need to strengthen the prevention and control of nosocomial infections and antimicrobial drug management in order to curb the spread of multidrug-resistant bacteria.202540522743
1140170.9997High abundance of the colistin resistance gene mcr-1 in chicken gut-bacteria in Bangladesh. Colistin is considered a last-resort reserved drug for the treatment of critical human infections by Gram-negative bacteria. Phenotypic colistin-resistance is strongly associated with plasmid-mediated mobile colistin resistance (mcr) genes. The mcr-bearing Enterobacteriaceae have been detected in many countries from environments, animals, and humans. This study investigated phenotypic colistin-resistance and the distribution of mcr-1, mcr-2, mcr-3, mcr-4, and mcr-5 genes in chicken-gut bacteria in Bangladesh. Bacteria were isolated from poultry- and native-chicken droppings, and their susceptibilities to colistin were determined by agar dilution and E-test minimal inhibitory concentration (MIC) measurements. Multiplex polymerase chain reactions detected mcr-1 to mcr-5 genes. Overall, 61.7% (92/149) of the isolates showed colistin resistance by agar dilution assessment (MIC > 2.0 μg/mL). The phenotypic resistance was observed considerably higher in poultry-chicken isolates (64.6%, 64/99) than in native-chicken isolates (56%, 28/50; p = 0.373). All the resistant isolates showed MIC levels between > 2 and > 128 μg/mL. The mcr-genes (mcr-1and mcr-2 combined) were detected more in poultry gut bacteria (36.4%) than native-chicken isolates (20%, p = 0.06). Despite bacteria sources, mcr-genes appeared to be significantly associated with phenotypic colistin-resistance phenomena (p < 0.001). Prior colistin usage led to a substantial increase in the proportion of bacteria with mcr-genes and phenotypic resistance (p < 0.001).202033057111
1830180.9997Shifts 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
852190.9997Antimicrobial Resistance in Bacteria Isolated from Exotic Pets: The Situation in the Iberian Peninsula. Literature related to antimicrobial resistant (AMR) bacteria in exotic pets is minimal, being essential to report objective data on this topic, which represents a therapeutic challenge for veterinary medicine and public health. Between 2016 and 2020, laboratory records of 3156 exotic pet specimens' microbiological diagnoses and antibiotic susceptibility testing (AST) results were examined. The samples were classified into three animal classes: birds (n = 412), mammalia (n = 2399), and reptilian (n = 345). The most prevalent bacteria in birds and mammals were Staphylococcus spp. (15% and 16%), while in reptiles they were Pseudomonas spp. (23%). Pseudomonas was the genus with the highest levels of AMR in all animal groups, followed by Enterococcus spp. By contrast, Gram-positive cocci and Pasteurella spp. were the most sensitive bacteria. Moreover, in reptiles, Stenotrophomonas spp., Morganella spp., and Acinetobacter spp. presented high levels of AMR. Multidrug-resistant (MDR) bacteria were isolates from reptiles (21%), birds (17%), and mammals (15%). The Enterobacterales had the highest MDR levels: S. marcescens (94.4%), C. freundii (50%), M. morganii (47.4%), K. pneumoniae (46.6%), E. cloacae (44%), and E. coli (38.3%). The prevalence of MDR P. aeruginosa strains was 8%, detecting one isolate with an XDR profile. Regarding antimicrobial use, many antibiotics described as critically important for human use had significant AMR prevalence in bacteria isolated from exotic pets. Under the One-Health approach, these results are alarming and of public health concern since potential transmission of AMR bacteria and genes can occur from exotic pets to their owners in both senses. For this reason, the collaboration between veterinarians and public health professionals is crucial.202235953901