# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 893 | 0 | 1.0000 | Epidemiology of Acinetobacter baumannii of animal origin. Acinetobacter baumannii is an opportunistic pathogen responsible for nosocomial infections, however the origins of these bacteria remain unclear. Sixteen A. baumannii strains collected from animals slaughtered for human consumption were investigated for their susceptibility profiles, resistance islands (RIs), class 1 integrons, insertion sequence ISAba1, and bla(OXA-51)-like and bla(AmpC) genes. Polymerase chain reaction (PCR) and sequencing approaches were used to identify and type the isolates using the intrinsic gene bla(OXA-51)-like genes. Genotyping was also performed by pulsed-field gel electrophoresis (PFGE) to establish whether there was a genetic relationship between animal isolates and the main human isolates of European clones I, II and III (ECI, ECII and ECIII) known to cause major hospital outbreaks. All 16 isolates (100%) were sensitive to carbapenems, gentamicin, ciprofloxacin and piperacillin/tazobactam but were resistant to amoxicillin, cefradine, trimethoprim and chloramphenicol. Moreover, all isolates had a baseline resistance to ceftazidime, with a minimum inhibitory concentration of 4 mg/L. All isolates lacked RIs, ISAba1 and class 1 integrons but harboured bla(OXA-51)-like and bla(AmpC) genes. In addition, this study reports for the first time three new bla(OXA-51)-like genes (bla(OXA-148), bla(OXA-149) and bla(OXA-150)) isolated from bacteria in cattle, which have not been found previously in human isolates. However, all isolates recovered from pig faecal samples harboured one type of bla(OXA-51)-like (bla(OXA-51) itself), which has already been reported in human clinical isolates. From sequencing of the bla(OXA-51)-like genes from animal isolates, it was possible to identify four different clusters similar to those identified by PFGE, which in turn also distinguished these four groups from the human ECI, ECII and ECIII strains. | 2011 | 21831604 |
| 892 | 1 | 0.9998 | Sequencing analysis of tigecycline resistance among tigecycline non-susceptible in three species of G-ve bacteria isolated from clinical specimens in Baghdad. BACKGROUND: Recent emergence of high-level tigecycline resistance is mediated by tet(X) genes in Gram-negative bacteria, which undoubtedly constitutes a serious threat for public health worldwide. This study aims to identify tigecycline non-susceptible isolates and detect the presence of genes that are responsible for tigecycline resistance among local isolates in Iraq for the first time. METHODS: Thirteen clinical isolates of Klebsiella pneumonia, Acinetobacter baumannii and Pseudomonas aeruginosa tigecycline non-susceptible were investigated from blood, sputum and burns specimens. The susceptibility of different antibiotics was tested by the VITEK-2 system. To detect tigecycline resistance genes, PCR was employed. RESULTS: Strains studied in this work were extremely drug-resistant and they were resistant to most antibiotic classes that were studied. The plasmid-encoded tet(X), tet(X1), tet(X2), tet(X3), tet(X4), tet(X5), tet(M) and tet(O) genes were not detected in the 13 isolates. The results showed that there is a clear presence of tet(A) and tet(B) genes in tigecycline non-susceptible isolates. All 13 (100%) tigecycline non-susceptible K. pneumoniae, A. baumannii and P. aeruginosa isolates harbored the tet(B) gene. In contrast, 4 (30.77%) tigecycline non-susceptible P. aeruginosa isolates harbored the tet(A) gene and there was no tigecycline non-susceptible A. baumannii isolate harboring the tet(A) gene (0%), but one (7.69%) tigecycline non-susceptible K. pneumoniae isolate harbored the tet(A) gene. A phylogenetic tree, which is based on the nucleotide sequences of the tet(A) gene, showed that the sequence of the local isolate was 87% similar to the nucleotide sequences for all the isolates used for comparison from GenBank and the local isolate displayed genetic diversity. CONCLUSIONS: According to this study, tet(B) and tet(A) play an important role in the appearance of tigecycline non-susceptible Gram-negative isolates. | 2022 | 36207501 |
| 870 | 2 | 0.9998 | Dissemination of multiple carbapenem-resistant clones of Acinetobacter baumannii in the Eastern District of Saudi Arabia. It has previously been shown that carbapenem-resistant Acinetobacter baumannii are frequently detected in Saudi Arabia. The present study aimed to identify the epidemiology and distribution of antibiotic resistance determinants in these bacteria. A total of 83 A. baumannii isolates were typed by pulsed-field gel electrophoresis (PFGE), and screened by PCR for carbapenemase genes and insertion sequences. Antibiotic sensitivity to imipenem, meropenem, tigecycline, and colistin were determined. Eight different PFGE groups were identified, and were spread across multiple hospitals. Many of the PFGE groups contained isolates belonging to World-wide clone 2. Carbapenem resistance or intermediate resistance was detected in 69% of isolates. The bla VIM gene was detected in 94% of isolates, while bla OXA-23-like genes were detected in 58%. The data demonstrate the co-existence and wide distribution of a number of clones of carbapenem-resistant A. baumannii carrying multiple carbapenem-resistance determinants within hospitals in the Eastern Region of Saudi Arabia. | 2015 | 26191044 |
| 872 | 3 | 0.9998 | Genomic Characterization of Carbapenem-Resistant Bacteria from Beef Cattle Feedlots. Carbapenems are considered a last resort for the treatment of multi-drug-resistant bacterial infections in humans. In this study, we investigated the occurrence of carbapenem-resistant bacteria in feedlots in Alberta, Canada. The presumptive carbapenem-resistant isolates (n = 116) recovered after ertapenem enrichment were subjected to antimicrobial susceptibility testing against 12 different antibiotics, including four carbapenems. Of these, 72% of the isolates (n = 84) showed resistance to ertapenem, while 27% of the isolates (n = 31) were resistant to at least one other carbapenem, with all except one isolate being resistant to at least two other drug classes. Of these 31 isolates, 90% were carbapenemase positive, while a subset of 36 ertapenem-only resistant isolates were carbapenemase negative. The positive isolates belonged to three genera; Pseudomonas, Acinetobacter, and Stenotrophomonas, with the majority being Pseudomonas aeruginosa (n = 20) as identified by 16S rRNA gene sequencing. Whole genome sequencing identified intrinsic carbapenem resistance genes, including blaOXA-50 and its variants (P. aeruginosa), blaOXA-265 (A. haemolyticus), blaOXA-648 (A. lwoffii), blaOXA-278 (A. junii), and blaL1 and blaL2 (S. maltophilia). The acquired carbapenem resistance gene (blaPST-2) was identified in P. saudiphocaensis and P. stutzeri. In a comparative genomic analysis, clinical P. aeruginosa clustered separately from those recovered from bovine feces. In conclusion, despite the use of selective enrichment methods, finding carbapenem-resistant bacteria within a feedlot environment was a rarity. | 2023 | 37370279 |
| 1648 | 4 | 0.9998 | Molecular characterization of the multi-drug resistant Myroides odoratimimus isolates: a whole genome sequence-based study to confirm carbapenem resistance. The bacteria belonging to the Myroides genus are opportunistic pathogens causing community or hospital-acquired infections that result in treatment failure due to antibiotic resistance. This study aimed to investigate molecular mechanisms of antibiotic resistance, clonal relatedness, and the biofilm forming capacity of the 51 multi-drug resistant Myroides odoratimimus. All isolates were screened for bla(KPC), bla(OXA), bla(VIM), bla(IMP), bla(MUS), bla(TUS), bla(NDM), and bla(B) genes by using PCR amplification. Whole genome sequencing (WGS) was applied on three randomly selected isolates for further investigation of antibiotic resistance mechanisms. Clonal relatedness was analyzed by Pulsed-field gel electrophoresis (PFGE) and the microtiter plate method was used to demonstrate biofilm formation. All isolates were positive for biofilm formation. PCR analysis resulted in a positive for only the bla(MUS-1) gene. WGS identified bla(MUS-1), erm(F), ere(D), tet(X), and sul2 genes in all strains tested. Moreover, the genomic analyses of three strains revealed that genomes contained a large number of virulence factors (VFs). PFGE yielded a clustering rate of 96%. High clonal relatedness, biofilm formation, and multi-drug resistance properties may lead to the predominance of these opportunistic pathogens in hospital environments and make them cause nosocomial infections. | 2024 | 38127105 |
| 871 | 5 | 0.9998 | Comparative 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. | 2023 | 37894090 |
| 1034 | 6 | 0.9998 | Detection 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. | 2024 | 38678422 |
| 2142 | 7 | 0.9998 | Resistance to β-lactams and distribution of β-lactam resistance genes in subgingival microbiota from Spanish patients with periodontitis. OBJECTIVES: The aim of this study was to analyze the distribution of β-lactamase genes and the multidrug resistance profiles in β-lactam-resistant subgingival bacteria from patients with periodontitis. MATERIALS AND METHODS: Subgingival samples were obtained from 130 Spanish patients with generalized periodontitis stage III or IV. Samples were grown on agar plates with amoxicillin or cefotaxime and incubated in anaerobic and microaerophilic conditions. Isolates were identified to the species level by the sequencing of their 16S rRNA gene. A screening for the following β-lactamase genes was performed by the polymerase chain reaction (PCR) technique: bla(TEM), bla(SHV), bla(CTX-M), bla(CfxA), bla(CepA), bla(CblA), and bla(ampC). Additionally, multidrug resistance to tetracycline, chloramphenicol, streptomycin, erythromycin, and kanamycin was assessed, growing the isolates on agar plates with breakpoint concentrations of each antimicrobial. RESULTS: β-lactam-resistant isolates were found in 83% of the patients. Seven hundred and thirty-seven isolates from 35 different genera were obtained, with Prevotella and Streptococcus being the most identified genera. bla(CfxA) was the gene most detected, being observed in 24.8% of the isolates, followed by bla(TEM) (12.9%). Most of the isolates (81.3%) were multidrug-resistant. CONCLUSIONS: This study shows that β-lactam resistance is widespread among Spanish patients with periodontitis. Furthermore, it suggests that the subgingival commensal microbiota might be a reservoir of multidrug resistance and β-lactamase genes. CLINICAL RELEVANCE: Most of the samples yielded β-lactam-resistant isolates, and 4 different groups of bla genes were detected among the isolates. Most of the isolates were also multidrug-resistant. The results show that, although β-lactams may still be effective, their future might be hindered by the presence of β-lactam-resistant bacteria and the presence of transferable bla genes. | 2020 | 32495224 |
| 866 | 8 | 0.9998 | Opening Pandora's box: High-level resistance to antibiotics of last resort in Gram-negative bacteria from Nigeria. OBJECTIVES: The aim of this study was to determine the percentage of antimicrobial-resistant isolates and the associated resistance mechanisms in Gram-negative bacteria from South Western Nigeria. METHODS: A total of 306 non-duplicate unbiased Gram-negative isolates were recovered from patients admitted to three teaching hospitals in South Western Nigeria in 2011 and 2013. Isolates were from clinical samples as well as from stool samples of inpatients without infection to assess antimicrobial resistance patterns in carriage isolates. Antimicrobial susceptibility testing was performed, and PCR and sequencing were used to identify genes encoding various known β-lactamases. Based on phenotypic and genotypic results, 10 isolates representing the diversity of phenotypes present were selected for whole-genome sequencing (WGS). RESULTS: Antimicrobial susceptibility testing revealed the following resistance rates: fluoroquinolones, 78.1%; third-generation cephalosporins, 92.2%; and carbapenems, 52.6%. More resistant isolates were isolated from stools of uninfected patients compared with clinical infection specimens. Klebsiella (10%) and Escherichia coli (7%) isolates produced a carbapenemase. WGS of selected isolates identified the presence of globally disseminated clones. CONCLUSION: This study illustrates a crisis for the use of first-line antimicrobial therapy in Nigerian patients. It is likely that Nigeria is playing a significant role in the spread of antimicrobial resistance owing to its large population with considerable global mobility. | 2020 | 31654790 |
| 919 | 9 | 0.9998 | Molecular Characteristics of Carbapenem-Resistant Enterobacter cloacae in Ningxia Province, China. The emergence of carbapenem-resistant Enterobacteriaceae (CRE) has become a major public health concern worldwide and a new challenge in the treatment of infectious diseases. The molecular characteristics of Enterobacter cloacae in Ningxia China are unknown. In this study, we reported 10 carbapenem-resistant E. cloacae isolates from the General Hospital of Ningxia Medical University, the largest university hospital in Ningxia between January 2012 and December 2013. Bacteria isolates were identified by Vitek2 compact and the identity of non-duplicate E. cloacae isolates was further confirmed by PCR and sequencing. The drug susceptibility and phenotype identification of these isolates were analyzed by agar dilution method, modified Hodge test (MHT), and EDTA synergy test. Beta-lactamase (bla) genes bla(NDM-1) was found in 8 out of 10 isolates. Most isolates harbored multiple resistance genes including bla(ESBL), bla(AmpC), quinolones, aminoglycosides, and disinfectant resistance genes. Pulsed field gel electrophoresis (PFGE) showed that these E. cloacae isolates were grouped into 6 clusters based on a cutoff of 80% genetic similarity. In conjugative assay, 9 out of 10 isolates transferred carbapenem-resistant genes to Escherichia coli. Our study has revealed that NDM-1-producing isolates are the most prevalent carbapenem-resistant E. cloacae in Ningxia. These isolates also carry several other carbapenem-resistant genes and can transfer these genes to other bacteria through conjugation. These findings highlight an urgent need to monitor these isolates to prevent their further spread in this region. | 2017 | 28197140 |
| 2150 | 10 | 0.9998 | Analysis of drug resistance genes of integrons in clinical isolates of Escherichia coli from elderly bloodstream infections. This experiment was carried out to provide a basis for the treatment of clinical bloodstream infections by analyzing the drug resistance characteristics and integrated gene distribution of Escherichia coli in bloodstream infections in elderly patients. For this aim, E. coli were collected for bacterial identification and drug sensitivity testing from bloodstream infections in elderly patients in the hospital from January 2016 to December 2019. ESBLs positive strains were assayed for genotypes and their integron carriage rates by PCR amplification. The characteristics and differences of various genotype rates were compared and analyzed. Results showed that a total of 230 E. coli strains were isolated. The detection rate of ESBLs-producing bacteria was 37.39 %. ESBLs-producing E. coli showed a high rate of resistance to cefepime, levofloxacin, cotrimoxazole, and ticarcillin/clavulanic acid (>40%). The resistance rate of 230 strains of E. coli to meropenem, minocycline, amikacin, gentamicin and cefoxitin was less than 20%. Among the ESBLs-producing E. coli in bloodstream infections in elderly patients, CTX-M-9 accounted for 27.91%, CTX-M-2 for 17.44%, and SHV for 13.95%. The detection rate of type I integrated genes was 41.30%, and type II and III integrated genes were not detected. ESBLs-producing genotyping-positive bacteria were detected with more than 50% of type I integrated genes. It was concluded that type I integrated genes in ESBLs-producing E. coli isolated from elderly patients carried resistance genes such as CTX-M-9 and CTX-M-2 aggravating multi-drug resistance in bacteria. | 2022 | 36227675 |
| 897 | 11 | 0.9998 | Prevalence of class 1 integrons and plasmid-mediated qnr-genes among Enterobacter isolates obtained from hospitalized patients in Ahvaz, Iran. Quinolones are frequently used classes of antimicrobials in hospitals, crucial for the treatment of infections caused by Gram-negative bacteria. The inappropriate use of quinolones and other antimicrobial agents for the treatment of bacterial infections leads to a significant increase of resistant isolates. The acquisition of antimicrobial resistance may be related to achievement of resistance determinant genes mediated by plasmids, transposons and gene cassettes in integrons. The objective of this cross-sectional study, conducted from December 2015 to July 2016 at two teaching hospitals in Ahvaz, southern Iran, was to screen for the presence of class 1 integrons and quinolone resistance genes in clinical isolates of Enterobacter spp. In all, 152 non-duplicated Enterobacter isolates were collected from clinical specimens and identified as Enterobacter spp. using standard microbiological methods. Antimicrobial susceptibility test was determined using the disc diffusion method according to the CLSI recommendation. Determination of class 1 integrons and PMQR genes was assessed by PCR. Analysis of antibiotic susceptibility tests showed that the highest antibiotic resistance was toward ciprofloxacin (55.3%), while the lowest level was observed against meropenem (34.9%). Moreover, 47.4% (72/152) and 29% (44/152) of isolates were positive for class 1 integron and quinolone resistance genes, respectively. The relative frequencies of antibiotic resistance were significantly higher among class 1 integron-positive isolates. In summary, our results highlight the importance of PMQR genes in the emergence of quinolone-resistant Enterobacter isolates. Moreover, it seems that class 1 integrons have a widespread distribution among Enterobacter isolates and have clinical relevance to multiple-drug-resistant isolates. | 2017 | 29286015 |
| 1054 | 12 | 0.9998 | Molecular detection of extended-spectrum β-lactamase-producing Klebsiella pneumoniae isolates of chicken origin from East Java, Indonesia. BACKGROUND AND AIM: Klebsiella pneumoniae is one of the respiratory disease agents in human and chicken. This bacterium is treated by antibiotic, but this treatment may trigger antibiotic resistance. Resistance gene in K. pneumoniae may be transferred to other bacteria. One of the known resistance genes is extended-spectrum β-lactamase (ESBL). This research aimed to study K. pneumoniae isolated from chicken farms in East Java, Indonesia, by observing the antibiotic resistance pattern and detect the presence of ESBL coding gene within the isolates. MATERIALS AND METHODS: A total of 11 K. pneumoniae isolates were collected from 141 chicken cloacal swabs from two regencies in East Java. All isolates were identified using the polymerase chain reaction method. Antimicrobial susceptibility was determined by agar dilution method on identified isolates, which then processed for molecular characterization to detect ESBL coding gene within the K. pneumoniae isolates found. RESULTS: The result of antibiotic sensitivity test in 11 isolates showed highest antibiotic resistance level toward ampicillin, amoxicillin, and oxytetracycline (100%, 100%, and 90.9%) and still sensitive to gentamicin. Resistance against colistin, doxycycline, ciprofloxacin, and enrofloxacin is varied by 90.9%, 54.5%, 27.3%, and 18.2%, respectively. All isolates of K. pneumoniae were classified as multidrug resistance (MDR) bacteria. Resistance gene analysis revealed the isolates harbored as bla (SHV) (9.1%), bla (TEM) (100%), and bla (CTX-M) (90.9%). CONCLUSION: All the bacterial isolates were classified as MDR bacteria and harbored two of the transmissible ESBL genes. The presence of antibiotic resistance genes in bacteria has the potential to spread its resistance properties. | 2019 | 31190714 |
| 1033 | 13 | 0.9998 | Antimicrobial Resistance and β-Lactamase Production in Clinically Significant Gram-Negative Bacteria Isolated from Hospital and Municipal Wastewater. Hospital and municipal wastewater contribute to the spread of antibiotic-resistant bacteria and genes in the environment. This study aimed to examine the antibiotic resistance and β-lactamase production in clinically significant Gram-negative bacteria isolated from hospital and municipal wastewater. The susceptibility of bacteria to antibiotics was tested using the disk diffusion method, and the presence of extended-spectrum β-lactamases (ESBL) and carbapenemases was determined using an enzyme inhibitor and standard multiplex PCR. Analysis of antimicrobial resistance of total bacterial strains (n = 23) revealed that most of them were resistant to cefotaxime (69.56%), imipenem (43.47%), meropenem (47.82%) and amoxicillin-clavulanate (43.47%), gentamicin (39.13%), cefepime and ciprofloxacin (34.78%), trimethoprim-sulfamethoxazole (30.43%). A total of 8 of 11 phenotypically confirmed isolates were found to have ESBL genes. The bla(TEM) gene was present in 2 of the isolates, while the bla(SHV) gene was found in 2 of the isolates. Furthermore, the bla(CTX-M) gene was found in 3 of the isolates. In one isolate, both the bla(TEM) and bla(SHV) genes were identified. Furthermore, of the 9 isolates that have been phenotypically confirmed to have carbapenemase, 3 were confirmed by PCR. Specifically, 2 isolates have the bla(OXA-48) type gene and 1 have the bla(NDM-1) gene. In conclusion, our investigation shows that there is a significant rate of bacteria that produce ESBL and carbapenemase, which can promote the spread of bacterial resistance. Identifying ESBL and carbapenemase production genes in wastewater samples and their resistance patterns can provide valuable data and guide the development of pathogen management strategies that could potentially help reduce the occurrence of multidrug resistance. | 2023 | 37107015 |
| 923 | 14 | 0.9998 | Prevalence of Oxacillinase Genes in Clinical Multidrug-Resistant Gram-Negative Bacteria. BACKGROUND: The emergence of OXA-type beta-lactamases has become a significant threat to public healthcare systems and may lead to prolonged hospital stays and increased mortality rates among affected patients. This study aimed to determine the prevalence of oxacillinase resistance (OXA) genes in multidrug-resistant (MDR) Gram-negative bacteria. METHODS: One hundred and six clinical isolates were collected from a stock of Gram-negative isolates and were identified and tested for antibiotic susceptibility and presence of OXA genes using polymerase chain reaction (PCR). RESULTS: The most common detected isolate was Klebsiella pneumoniae (36.8%), followed by Escherichia coli (33%), Pseudomonas aeruginosa (16%), and Acinetobacter baumannii (14.2%). Out of these isolates, 97.4%, 87.2%, 84.6%, and 79.5% were resistant to ampicillin/sulbactam, cefotaxime, ceftazidime, and aztreonam, respectively. PCR results confirmed the presence of one or more OXA genes in 34% of the samples studied. The blaOXA-1 and blaOXA-10 genes were the most highly detected genes, followed by blaOXA-4 and blaOXA-51. The total number of Pseudomonas aeruginosa isolates was confirmed to carry at least one OXA gene (70.6%), whereas Acinetobacter baumannii, Klebsiella pneumoniae, and Escherichia coli were confirmed to carry at least one OXA gene (53.3, 28.2, and 22.9%, respectively). There was a significant association (p < 0.05) between the resistance genes and the type of isolate. CONCLUSIONS: Pseudomonas aeruginosa and Acinetobacter baumannii are the most common MDR Gram-negative strains carrying OXA-type beta-lactamase genes. Monitoring of MDR pathogens in Gram-negative bacteria must be continuously undertaken to implement effective measures for infection control and prevention. | 2025 | 40066541 |
| 1055 | 15 | 0.9998 | Antimicrobial Susceptibility and Molecular Identification of Antibiotic Resistance Enteric Bacteria Isolated From Pigeon Feces in the City of Jeddah, Saudi Arabia. Background Due to their potential to carry a wide range of bacteria, pigeon feces may contribute to the spreading of infectious diseases in urban settings. Objective This study analyzed the presence of enteric bacteria from pigeon feces in Jeddah and their antimicrobial susceptibility and described the molecular characteristics of the carbapenem resistance genes it produced. Method Two hundred twenty-five pigeon feces specimens were collected from eight parks in Jeddah. Conventional microbiology techniques were employed to identify the isolated bacteria, and the automated Vitek2® system (bioMérieux, Marcy-l'Étoile, Lyon, France) provided additional confirmation. Kirby-Bauer disk diffusion method was utilized to screen for antimicrobial resistance. Only 50 antibiotic-resistance isolates further underwent molecular diagnosis for testing groups of carbapenems-encoding genes (blaNDM, blaSIM, and blaAIM), using multiplex polymerase chain reaction (PCR). Result Of the 50 antibiotic-resistant isolates, 28% (14/50) were Klebsiella pneumoniae, 24% (12/50) were Enterobacter cloacae, and 48% (24/50) were Escherichia coli. Ninety percent (90%) of the isolates showed resistance to cefuroxime, 56% to gentamicin, 52% to amoxicillin/clavulanic acid, and 100% to meropenem. NDM beta-lactamase was the most often discovered gene (26%) and was followed by AIM beta-lactamase (5%) Conclusion According to this study, there may be a chance for resistant K. pneumoniae, E. cloacae, and E. coli to spread amongst several hosts within the same area. Consequently, to prevent the continued occurrence and dissemination of resistant strains among other hosts in the same location, it is essential to monitor the AMR (antimicrobial resistance) of E. coli, E. cloacae, and K. pneumoniae from pigeons. | 2024 | 39310621 |
| 1031 | 16 | 0.9998 | Beta-lactams resistance and presence of class 1 integron in Pseudomonas spp. isolated from untreated hospital effluents in Brazil. The aim of the present study was to investigate the resistance profile, to detect the presence of beta-lactam resistance genes, phenotypic expression of efflux pump systems and class 1 integrons in Pseudomonas spp. strains obtained from untreated hospital effluents. Effluent samples were collected from four hospitals in Porto Alegre, RS, Brazil. Pseudomonas were isolated on MacConkey agar plates and the identification was confirmed by 16S rRNA PCR and biochemical tests. Susceptibility testing was determined by disk-diffusion method using 11 different beta-lactams and MIC assays were performed on isolates resistant to imipenem and ceftazidime. The beta-lactamase genes bla (IMP), bla (VIM), bla (SPM-1), bla (OXA-23-like), bla (OXA-24-like), bla (OXA-51-like) and the intl1 gene from class 1 integron were analysed by PCR. One hundred and twenty-four isolates were recovered and the most common species was Pseudomonas pseudoalcaligenes. The resistance found among the isolates was considered high, 62 (50%) isolates were multiresistant. No isolate carrying the beta-lactamase genes tested was found among the strains. Seven isolates showed reduction of MIC for imipenem and ceftazidime in the presence of cyanide m-chlorophenylhydrazone, indicating the hyper expression of efflux pumps. From the 124 isolates, 52 (41.9%) were identified as carrying the class 1 integron gene, intI1. Untreated hospital effluents could be a source of environmental contamination due to discharge of antimicrobial resistant bacteria which can carry integron class 1 and act as a reservoir of resistance genes and have efflux pump systems. | 2012 | 22382676 |
| 862 | 17 | 0.9998 | Emergence of plasmid-mediated mcr genes from Gram-negative bacteria at the human-animal interface. BACKGROUND: The global emergence of plasmid-mediated colistin resistance (Col-R) conferred by mcr genes in gram-negative rods (GNRs) has jeopardized the last treatment option for multidrug-resistant bacterial infections in humans. This study aimed to assess the emergence of mcr gene-mediated Col-R in GNRs isolated from humans and animals in Pakistan. METHODS: Animal and clinical specimens collected from various sources were prospectively analysed using standard microbiological procedures. Pathogens were identified using the API 20E and API 20NE systems (bioMerieux). Minimum inhibitory concentration (MIC) against colistin was determined using the MIC detection methods, and multiplex polymerase chain reaction (PCR) was used to amplify the mcr-1 to mcr-5 genes. RESULTS: We isolated 126 (88.1%) animal and 17 (11.9%) human Col-R phenotypes, among which there was a significant association (P < 0.01) of Escherichia coli and Proteus mirabilis with animals and of Acinetobacter baumannii with humans. Animal strains exhibited statistically significant (P < 0.05) resistance to co-trimoxazole, chloramphenicol, and moxifloxacin, and the human pathogens exhibited statistically significant (P < 0.05) antibiotic resistance to cephalosporins, carbapenems, and piperacillin-tazobactam. For Col-R strains, MIC(50) values were > 6 µg/mL and > 12 µg/mL for human and animal isolates, respectively. mcr genes were detected in 110 (76.9%) bacterial strains, of which 108 (98.2%) were mcr-1 and 2 (1.8%) were mcr-2. CONCLUSIONS: The detection of a considerable number of mcr-1 and mcr-2 genes in animals is worrisome, as they are now being detected in clinical pathogens. The acquisition of mcr genes by colistin-susceptible bacteria could leave us in a post-antibiotic era. | 2020 | 33292525 |
| 896 | 18 | 0.9998 | Retrospective Screening and Analysis of mcr-1 and bla (NDM) in Gram-Negative Bacteria in China, 2010-2019. Currently, Gram-negative bacteria have developed multidrug and broad-spectrum drug resistance, and the numbers of species and strains carrying mcr or bla (NDM) genes are increasing. In this study, mcr-1 and bla (NDM) distribution of 12,858 Gram-negative bacteria isolated from wildlife, patients, livestock, poultry and environment in 14 provinces of China from 2010 to 2019 and the antibiotics resistance in regard to polymyxins (polymyxin B and colistin) and carbapenems of positive strains were investigated. A total of 70 strains of 10 species carried the mcr-1 gene, positive rates of patients, livestock and poultry, and environmental strains were 0.62% (36/5,828), 4.07% (29/712), 5.43% (5/92), respectively. Six strains of 3 species carrying the bla (NDM) gene all came from patients 0.10% (6/5,828). Two new mcr-1 gene variants (GenBank: MK965883, MK965884) were identified, one of which contains premature stop codon. The drug susceptibility results showed that all mcr-1 carriers were sensitive to carbapenems, among which, 66 strains were resistant and 4 were sensitive to polymyxins. The strains with the bla (NDM) gene had different degrees of resistance to carbapenems and were sensitive to polymyxins. The findings that species carrying mcr-1 or bla (NDM) genes were limited and mostly normal flora of opportunistic or low pathogenic organisms indicated that transfer of mcr-1 and bla (NDM) genes between bacteria was relatively limited in China. The none detection among wildlife compared with other sources supports the speculation that the emergence of and increase in polymyxins and carbapenem-resistant strains was mainly related to the selective pressure of antibiotics. | 2020 | 32117144 |
| 869 | 19 | 0.9998 | The 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. | 2024 | 38786157 |