Clinical Klebsiella pneumoniae isolates and their efflux pump mechanism for antibiotic resistance challenge. - Related Documents




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231601.0000Clinical Klebsiella pneumoniae isolates and their efflux pump mechanism for antibiotic resistance challenge. BACKGROUND: Klebsiella pneumoniae is a serious pathogen that causes many disorders in humans and animals. Klebsiella pneumoniae, which is one of the most important pathogens in hospitals, often causes many clinical manifestations, including pneumonia, urinary tract infections, and meningitis. Interest in this bacterium has increased due to the increasing incidence of infection caused by it, as well as its high resistance to antibiotics, especially broad-spectrum antibiotics. AIM: This study showed the efflux pump mechanism of clinical K. pneumoniae isolates and antibiotic resistance in samples collected from sheep and human respiratory tract infection in southern Iraq. METHODS: Three hundred samples were collected, and the samples included: 150 nasal swabs from sheep and 150 sputum samples from humans. Through bacteriological and biochemical examinations. The isolates were identified K. pneumoniae isolates were also confirmed by 16S rRNA. Susceptibility testing of the antibiotics used in the study. To determine the phenotypic efflux pump activity, the agar ethidium bromide cartwheel method was used. RESULTS: Of 150 sputum human specimens and 150 nasal swabs from sheep were tested, 25 and 17 K. pneumoniae species isolates from patients and sheep, respectively, for the resistance of the bacteria isolated from humans to antibiotics. The highest rate of resistance was to piperacillin (88%), and the lowest rate was to antibiotics (36%), imipenem. The highest of bacterial susceptibility to the antibiotic imipenem was (44%) and (36%) for levofloxacin, respectively. For the bacterial isolates from sheep, the highest percentage of resistance to rifampin was (82.3%), and the highest percentage of sensitivity was to imipenem and Levofloxacin antibiotics. The results showed that most of the 39 bacterial isolates (92.8%) possessed an efflux pump mechanism. The result of genotyping to identify the efflux pump genes tolC and acrAB revealed that all isolates carried the genes. CONCLUSION: All the isolates were resistant to antibiotics, and the bacterial isolates under study most possess the efflux pump mechanism. All bacteria also have efflux pump genes, and this gives the bacteria more resistance against many antibiotics.202541036356
231710.9999Molecular Detection of Adefg Efflux Pump Genes and their Contribution to Antibiotic Resistance in Acinetobacter baumannii Clinical Isolates. BACKGROUND: Acinetobacter baumannii (A. baumannii) is one of the most important bacteria causing nosocomial infections worldwide. Over the past few years, several strains of A. baumannii have shown antibiotic resistance, which may be due to the activity of efflux pumps. This study was aimed to detect AdeFG efflux pump genes and their contribution to antibiotic resistance in A. baumannii clinical isolates. METHODS: A total of 200 A. baumannii clinical isolates were collected from clinical specimens of ulcers, pus, sputum, and blood. All isolates were identified using standard biochemical tests. After identifying and cleaving the genome by boiling, PCR was performed on samples using specific primers. The antimicrobial susceptibility patterns were determined by disk diffusion, with and without CCCP efflux pump inhibitor were determined according to CLSI guidelines. RESULTS: We identified 60 clinical isolates of A. baumannii using biochemical differential tests. Identification of all A. baumannii isolates was confirmed by blaOXA-51-like PCR. According to the results of our study, 98.37% of A. baumannii isolates were resistant to ciprofloxacin, norfloxacin, and levofloxacin. PCR results indicated that all 60 A. baumannii isolates contained the AdeF and 76.66% contained AdeG. CONCLUSION: the results of this study demonstrated that most of the A. baumannii isolates contained AdeF and AdeG efflux pump genes, and more than 98% of the isolates were resistant to ciprofloxacin, norfloxacin, and levofloxacin. This reflected the significant contribution of efflux pumps to the development of resistance to these antibiotics.202032582800
232720.9999Identification of Quinolone and Colistin Resistance Genes in Escherichia Coli Strains Isolated from Mucosal Samples of Patients with Colorectal Cancer and Healthy Subjects. INTRODUCTION: Antibiotic resistance and extensive use of antibiotics are amongst the major causes of failure in antibiotic treatment. The purpose of this study was to investigate antibiotic resistance patterns and to identify resistance genes of quinolones and colistin in Escherichia coli. There are a very few patents on E. coli isolated from colorectal cancer. So, this study demonstrates that some bacteria resistant to ciprofloxacin have not resistance genes.Moreover, new patterns for E. coli are presented for isolates of patients with colorectal cancer. MATERIALS AND METHODS: Of the three healthy people, inflammatory bowel diseases (IBD) patients and colorectal cancer patients, 40 E. coli strains isolated after confirmation by biochemical and molecular methods. The susceptibility of isolates to antibiotics was investigated using disk diffusion test. After deoxyribonucleic acid (DNA) extraction, polymerase chain reaction (PCR) was used to identify genes encoding resistance to ciprofloxacin (qnr A, qnr B) and colistin (mcr-1). RESULTS: The results showed that E. coli isolates from colorectal cancer patients had the highest resistance to piperacillin (67.5%), ceftazidime (47.5%), and cefepime (42.5%). Also, E. coli strains isolated from IBD patients showed resistance to antibiotic ceftazidime 13%. More than 95% of E. coli strains isolated from healthy people were susceptible to antibiotics. Based on the results, 18 (15%) E. coli strains showed resistance to ciprofloxacin. The qnr A gene was detected in 61.11% isolates; however, qnr B was detected in 9 (50%) isolates. Isolates resistant to colistin were not observed. CONCLUSION: These findings indicate increased resistance of E. coli to ciprofloxacin in comparison with prior studies. Further research in this field will increase our knowledge and more effective exposure to the antibiotic resistance of the pathogenic microorganisms.202031198116
230530.9999In-vitro activity of tigecycline against multidrug-resistant Gram negative bacteria: The experience of a university hospital. The emergence of multidrug-resistant Gram negative bacteria has given rise to significant therapeutic challenges. These pathogens may have developed resistance to tigecycline, which is an alternative antibiotic used empirically in the treatment of serious infections. The objectives of this study were to identify the in-vitro activity of tigecycline against multidrug-resistant Gram negative strains isolated from clinical specimens and their related genes, at a university hospital. For this, 150 clinical isolates of multidrug-resistant Gram negative cultures from various clinical specimens were collected. Bacterial isolates were cultured, identified and their antibiotic susceptibilities were determined. Polymerase chain reaction was performed to amplify AcrB, AmpC, RamR, MexR, AdeB, TetA genes. Results revealed that all isolates were multidrug-resistant. The resistance of isolates was 91.4% to aztreonam, 94.6% to piperacillin, 34% to imipenem, 38.7% to meropenem, 71.3% to levofloxacin, 97.3% to ceftriaxone, 94.7% to cefepime, 9.3% to colistin, 78% to tetracycline, 21.4% to tigecycline and 68% to trimethoprim. AcrB, AmpC, RamR, MexR, AdeB, TetA genes were present in multidrug-resistant Gram negative bacteria. AcrB, RamR, TetA genes were related to tigecycline resistance. It is concluded that infections caused by multidrug-resistant Gram negative bacteria occur at a high rate. Most isolates were multi drug resistant, with 21.4% being resistant to tigecycline.202133743369
230640.9999Resistance 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
230250.9999Antibiotic 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
230860.9999Trends of Antibiotic Resistance in Multidrug-Resistant Pathogens Isolated from Blood Cultures in a Four-Year Period. BACKGROUND: Multidrug-resistant organisms cause serious infections with significant morbidity and mortality in the worldwide. These organisms have been identified as urgent and serious threats by CDC. The aim of this study was to determine the prevalence and changes of antibiotic resistance of multidrug-resistant pathogens isolated from blood cultures over a four-year period in a tertiary-care hospital. METHODS: Blood cultures were incubated in a blood culture system. Positive signalling blood cultures were subcultured on 5% sheep-blood agar. Identification of isolated bacteria was performed using conventional or automated identification systems. Antibiotic susceptibility tests were performed by disc diffusion and/or gradient test methods, if necessary, by automated systems. The CLSI guidelines were used for interpretation of antibiotic susceptibility testing of bacteria. RESULTS: The most frequently isolated Gram-negative bacteria was Escherichia coli (33.4%) followed by Klebsiella pneumoniae (21.5%). ESBL positivity was 47% for E. coli, 66% for K. pneumoniae. Among E. coli, K. pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii isolates, carbapenem resistance was 4%, 41%, 37%, and 62%, respectively. Carbapenem resistance of K. pneumoniae isolates has increased from 25% to 57% over the years, and the highest rate (57%) occured during the pandemic period. It is noteworthy that the aminoglycoside resistance in E. coli isolates gradually increased from 2017 to 2021. The rate of methicillin-resistant S. aureus (MRSA) was found to be 35.5%. CONCLUSIONS: Increased carbapenem resistance in K. pneumoniae and A. baumannii isolates is noteworthy, but carbapenem resistance in P. aeruginosa decreased. It is of great importance for each hospital to monitor the increase in resistance in clinically important bacteria, especially isolated from invasive samples, in order to take the necessary precautions in a timely manner. Future studies involving clinical data of patients and bacterial resistance genes are warranted.202337307126
231970.9998Bacterial resistance to antibiotics and associated factors in two hospital centers in Lebanon from January 2017 to June 2017. GENERAL PRESENTATION: Resistance of bacteria to antibiotics is a universal problem. With the increase in the rate of resistance, knowledge of susceptibility patterns is essential to guide antimicrobial therapy. In Lebanon, many studies investigated this subject. OBJECTIVES: Determine the rate of multidrug and extremely drug-resistant bacteria as well as the patterns of resistance and the factors associated with this resistance. MATERIALS AND METHODS: A cross-sectional study was performed using the cultures from the labs of two university hospitals in Lebanon. Bacteria were divided into four groups: sensitive, multidrug-, extremely- and pan-drug resistant. Patient information was obtained from the medical records. Using the SPSS software for Windows, version 20 (IBM, Armonk, USA), the frequency of the bacteria, their susceptibilities and the association of resistance with seven potential factors (age, gender, diabetes mellitus, cancer, chronic kidney disease, dialysis, previous hospitalization) were studied. RESULTS: The frequency of resistance was 53.7% (39.9% multidrug-resistant and 13.8% extremely drug-resistant). Escherichia coli strains were mostly susceptible to carbapenems and tigecycline; and nitrofurantoine and fosfomycin in urine. Pseudomonas and Acinetobacter species were mostly sensitive to colistin. Klebsiella species were mostly susceptible to amikacin and carbapenems. MRSA rates were 34.8%. Association was seen between the resistant bacteria and older age, chronic kidney disease, dialysis, and previous hospitalization. CONCLUSION: Resistance of bacteria to drugs in Lebanon is increasing. Significant association is seen between these bacteria and older age, chronic kidney disease, dialysis, and previous hospitalization.202034368694
236380.9998Analysis of distribution and antibiotic resistance of Gram-positive bacteria isolated from a tertiary-care hospital in southern China: an 8-year retrospective study. OBJECTIVE: Due to the severe drug resistance situation of Gram-negative bacteria, especially Gram-negative enterobacter, relatively little attention has been paid to the changes in Gram-positive bacteria species and drug resistance. Therefore, this study analyzed the prevalence and drug resistance of Gram-positive bacteria in a general tertiary-care hospital from 2014 to 2021, in order to discover the changes in Gram-positive bacteria distribution and drug resistance that cannot be easily identified, inform clinicians in their respective regions when selecting antimicrobial agents, and to provide the basis for the diagnosis of Gram-positive bacterial infection, and for the comprehensive and multi-pronged prevention and control of drug-resistant bacteria. METHODS: A retrospective study was conducted on Gram-positive bacteria isolated from patients presented to a general tertiary-care hospital from January 2014 to December 2021. A total of 15,217 Gram-positive strains were analyzed. RESULTS: During the 8-year period, the total number and the species of Gram-positive bacteria isolated from clinic increased continuously. The seven most common species were Streptococcus pneumoniae (21.2%), Staphylococcus aureus (15.9%), Enterococcus faecium (20.6%), Enterococcus faecalis (14.0%), and Staphylococcus epidermidis (7.8%), Staphylococcus haemolyticus (4.8%), Streptococcus agalactiae (3.6%). The isolation rates of Staphylococcus aureus and Streptococcus agalactiae increased, and the isolation rate of Enterococcus faecium decreased. The resistance rates of Staphylococcus aureus to erythromycin, clindamycin, tetracycline, rifampicin and furantoin decreased obviously. The resistance rates of Streptococcus pneumoniae to cefepime (non-meningitis) and ceftriaxone (meningitis) decreased significantly. The resistance rates of Enterococcus faecium to penicillin, ampicillin, erythromycin, levofloxacin, ciprofloxacin and furantoin rose rapidly from 50.3, 47.6, 71.5, 44.9, 52.3, and 37.5% in 2014 to 93.1, 91.6, 84.9, 86.8, 86.8, and 60.0% in 2021, respectively. CONCLUSION: The total number and the species of Gram-positive bacteria isolated during the 8-year period increased continuously. Streptococcus pneumoniae and Staphylococcus aureus are the main causes of positive bacterial infections in this hospital. The resistance rates of Enterococcus faecium to a variety of commonly used antibiotics increased significantly. Therefore, it is very important to monitor the distribution of bacteria and their resistance to antibiotics to timely evaluate and identify changes in drug resistance that are not easily detected.202337840716
215890.9998Relationship of OqxAB efflux pump to antibiotic resistance, mainly fluoroquinolones in Klebsiella pneumoniae, isolated from hospitalized patients. OBJECTIVES: This research was designed to study the prevalence of OqxAB efflux pump genes and also to investigate the relationship between efflux pump and resistance to antibiotics, especially to fluoroquinolones, evaluate the expression levels of OqxAB genes, and molecular typing of Klebsiella pneumoniae isolated from hospitalized patients in Hamadan hospitals, west of Iran. MATERIALS AND METHODS: In a cross-sectional study, 100 clinical strains of K. pneumoniae were isolated from hospitalized patients in three major teaching hospitals from January to June 2021. The antibiotic susceptibility of isolates was evaluated by the disk-diffusion agar method. The frequency of genes encoding oqxA and oqxB of efflux pump genes was investigated by PCR, and the expression of the oqxA efflux pump gene was investigated by the Real-time PCR method. The genetic relationship of K. pneumoniae isolates was analyzed by the Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR technique. RESULTS: According to our results, the multi-drug resistance phenotype (MDR) in 65% and high prevalence resistance to ciprofloxacin in 89% of K. pneumoniae isolates was detected. The higher prevalence of oqxA (95%) and oqxB (98%) was also detected. There was a significant relationship between ciprofloxacin resistance and the oqxB gene as well as between ceftriaxone and chloramphenicol resistance and the oqxA gene. The expression of the oqxA gene was higher in ciprofloxacin-resistant isolates. CONCLUSION: The results of this study suggest a potential reservoir for the spread of OqxAB genes among hospital-acquired bacteria. Infection control strategies should be used prudently to reduce the spread of resistant strains of K. pneumoniae in hospitals.202336594055
2355100.9998Causative bacteria and antibiotic resistance in neonatal sepsis. BACKGROUND: Neonatal sepsis is characterised by bacteraemia and clinical symptoms caused by microorganisms and their toxic products. Gram negative bacteria are the commonest causes of neonatal Sepsis. The resistance to the commonly used antibiotics is alarmingly high. The major reason for emerging resistance against antibiotics is that doctors often do not take blood cultures before starting antibiotics. We have carried out this study to find out various bacteria causing neonatal sepsis and their susceptibility to antibiotics for better management of neonatal sepsis. METHODS: A total of 130 neonates with sepsis who were found to be blood culture positive were taken in this study. Culture/sensitivity was done, isolated organisms identified and their sensitivity/resistance was noted against different antibiotics. Data were arranged in terms of frequencies and percentage. RESULTS: Out of 130 culture proven cases of neonatal sepsis, gram negative bacteria were found in 71 (54.6%) cases and gram positive bacteria in 59 (45.4%) cases. Staphylococcus aureus was the most common bacteria found in 35 (26.9%) cases followed by Escherichia coli in 30 (23.1%) cases. Acinetobacter species, Staphylococcus epidermidis, Klebseila, Streptococci, Enterobacter cloacae and Morexella species were found in 17 (13.1%), 17 (13.1%), 13 (10%), 7 (5.4%), 6 (4.6%), and 5 (3.8%) cases respectively. In most of the cases causative organisms were found to be resistant to commonly used antibiotics like ampicillin, amoxicillin, cefotaxime, and ceftriaxone (77.7%, 81.5%, 63.1%, and 66.9% respectively). There was comparatively less (56.9%) resistance to ceftazidime. Gentamicin had resistance in 55.1% cases, while amikacin and tobramycin had relatively less resistance (17.4% and 34.8% cases respectively). Quinolones and imipenem had relatively less resistance. Vancomycin was found to be effective in 100% cases of Staphylococcus group. CONCLUSION: Staphylococcus aureus are the most common gram positive bacteria and Escherichia coli are the most common gram negative bacteria causing neonatal sepsis. Resistance to commonly used antibiotics is alarmingly increasing. Continued surveillance is mandatory to assess the resistance pattern at a certain level.201224669633
2291110.9998Multiple mechanisms contributing to ciprofloxacin resistance among Gram negative bacteria causing infections to cancer patients. Fluoroquinolones have been used for prophylaxis against infections in cancer patients but their impact on the resistance mechanisms still require further investigation. To elucidate mechanisms underlying ciprofloxacin (CIP) resistance in Gram-negative pathogens causing infections to cancer patients, 169 isolates were investigated. Broth microdilution assays showed high-level CIP resistance in 89.3% of the isolates. Target site mutations were analyzed using PCR and DNA sequencing in 15 selected isolates. Of them, all had gyrA mutations (codons 83 and 87) with parC mutations (codons 80 and 84) in 93.3%. All isolates were screened for plasmid-mediated quinolone resistance (PMQR) genes and 56.8% of them were positive in this respect. Among PMQR genes, aac(6')-Ib-cr predominated (42.6%) while qnr genes were harbored by 32.5%. This comprised qnrS in 26.6% and qnrB in 6.5%. Clonality of the qnr-positive isolates using ERIC-PCR revealed that most of them were not clonal. CIP MIC reduction by CCCP, an efflux pump inhibitor, was studied and the results revealed that contribution of efflux activity was observed in 18.3% of the isolates. Furthermore, most fluoroquinolone resistance mechanisms were detected among Gram-negative isolates recovered from cancer patients. Target site mutations had the highest impact on CIP resistance as compared to PMQRs and efflux activity.201830115947
2329120.9998Antibiotic resistance and genotyping of clinical group B Salmonella isolated in Accra, Ghana. AIMS: The purpose of this study was to investigate the antibiotic resistance and clonal lineage of serogroup B Salmonella isolated from patients suspected of suffering from enteric fever in Accra, Ghana. METHODS AND RESULTS: Serogroup B Salmonella were isolated from blood (n=28), cerebral spinal fluid (CSF) (n=1), or urine (n=2), and identified based on standard biochemical testing and agglutinating antisera. Isolates were examined for their susceptibility to ampicillin, chloramphenicol, tetracycline and trimethoprim-sulfamethoxazole. Most of the isolates could be classified as multiple-drug resistant. Furthermore, the genetic location of resistance genes was shown to be on conjugative plasmids. Genetic fingerprinting by plasmid profiling, enterobacterial repetitive intergenic consensus (ERIC)-PCR, and repetitive element (REP)-PCR were performed to determine the diversity among the isolates. Plasmid profiling discriminated five unique groupings, while ERIC-PCR and REP-PCR resulted in two and three groupings, respectively. CONCLUSIONS: A high rate of antibiotic resistance was associated with the Salmonella isolates and the genes responsible for the resistance are located on conjugative plasmids. Also, there appears to be minimal diversity associated with the isolates. SIGNIFICANCE AND IMPACT OF THE STUDY: As a result of the increasing antibiotic resistance among bacteria of all genera, surveys to monitor microbial populations are critical to determine the extent of the problem. The inability to treat many infectious diseases with current antibiotic regimens should prompt the medical community to be more prudent with its antibiotic use.200312534821
2303130.9998Patterns of Drug-Resistant Bacteria in a General Hospital, China, 2011-2016. Drug-resistant bacteria has been a threat to public life and property. We described the trends and changes in antibiotic resistance of important pathogens in a general hospital in Zhengzhou, China from 2011 to 2016, to control antimicrobial-resistant bacteria in hospital and provide support to clinicians and decision-making departments. Five dominant bacteria were enrolled based on the data from the general hospital during 6 years. The results of antimicrobial susceptibility testing were interpreted according to Clinical and Laboratory Standards Institute (CLSI). From 2011 to 2016, a total of 19,260 strains of bacteria were isolated, of which Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii accounted for 51.98%. The resistance rate of K. pneumoniae and E. coli to carbapenem was less than 15%, but resistance of K. pneumoniae to carbapenems increased with time and resistance of E. coli to meropenem increased. The rate of extended-spectrum beta-lactamase (ESBL) production among K. pneumoniae and E. coli was decreasing. For most antibiotics, the resistance rate of ESBL-positive isolates was higher than that of ESBL-negative isolates, excluding carbapenems and cefoxitin. For S. aureus, the rate of methicillin-resistant S. aureus (MRSA) was stable. Resistance of S. aureus to mostly antibiotics decreased with time. Besides polymyxin B, P. aeruginosa and A. baumannii showed high resistance to other antibiotics. For A. baumannii, the resistance rate to mostly antibiotics was increasing. The bacteria showed high levels of resistance and multiple drug resistance. Continuous surveillance and optimizing the use of antibiotics are essential. Drug-resistant bacteria has been a threat to public life and property. We described the trends and changes in antibiotic resistance of important pathogens in a general hospital in Zhengzhou, China from 2011 to 2016, to control antimicrobial-resistant bacteria in hospital and provide support to clinicians and decision-making departments. Five dominant bacteria were enrolled based on the data from the general hospital during 6 years. The results of antimicrobial susceptibility testing were interpreted according to Clinical and Laboratory Standards Institute (CLSI). From 2011 to 2016, a total of 19,260 strains of bacteria were isolated, of which Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii accounted for 51.98%. The resistance rate of K. pneumoniae and E. coli to carbapenem was less than 15%, but resistance of K. pneumoniae to carbapenems increased with time and resistance of E. coli to meropenem increased. The rate of extended-spectrum beta-lactamase (ESBL) production among K. pneumoniae and E. coli was decreasing. For most antibiotics, the resistance rate of ESBL-positive isolates was higher than that of ESBL-negative isolates, excluding carbapenems and cefoxitin. For S. aureus, the rate of methicillin-resistant S. aureus (MRSA) was stable. Resistance of S. aureus to mostly antibiotics decreased with time. Besides polymyxin B, P. aeruginosa and A. baumannii showed high resistance to other antibiotics. For A. baumannii, the resistance rate to mostly antibiotics was increasing. The bacteria showed high levels of resistance and multiple drug resistance. Continuous surveillance and optimizing the use of antibiotics are essential.201931250593
2304140.9998Antimicrobial 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
2356150.9998Occurrence of Multiple-Drug Resistance Bacteria and Their Antimicrobial Resistance Patterns in Burn Infections from Southwest of Iran. Burn infection continues to be a major issue of concern globally and causes more harm to developing countries. This study aimed to identify the aerobic bacteriological profiles and antimicrobial resistance patterns of burn infections in three hospitals in Abadan, southwest Iran. The cultures of various clinical samples obtained from 325 burn patients were investigated from January to December 2019. All bacterial isolates were identified based on the standard microbiological procedures. Antibiotic susceptibility tests were performed according to the CLSI. A total of 287 bacterial species were isolated from burn patients. Pseudomonas aeruginosa was the most frequent bacterial isolate in Gram-negative bacteria and S. epidermidis was the most frequent species isolated in Gram-positive bacteria. The maximum resistance was found to ampicillin, gentamicin, ciprofloxacin, while in Gram-negative bacteria, the maximum resistance was found to imipenem, gentamicin, ciprofloxacin, ceftazidime, and amikacin. The occurrence of multidrug resistance phenotype was as follows: P. aeruginosa (30.3%), Enterobacter spp (11.1%), Escherichia coli (10.5%), Citrobacter spp (2.1%), S. epidermidis (2.8%), S. aureus, and S. saprophyticus (0.7%). Owing to the diverse range of bacteria that cause burn wound infection, regular investigation, and diagnosis of common bacteria and their resistance patterns is recommended to determine the proper antibiotic regimen for appropriate therapy.202234236077
5787160.9998Investigation of the association of virulence genes and biofilm production with infection and bacterial colonization processes in multidrug-resistant Acinetobacter spp. The aim of this study was to evaluate the phenotypic and molecular patterns of biofilm formation in infection and colonization isolates of Acinetobacter spp. from patients who were admitted in a public hospital of Recife-PE-Brazil in 2018-2019. For the biofilm phenotypic analysis, Acinetobacter spp. isolates were evaluated by the crystal violet staining method; the search of virulence genes (bap, ompA, epsA, csuE and bfmS) was performed by PCR; and the ERIC-PCR was performed for molecular typing. Amongst the 38 Acinetobacter spp. isolates, 20 were isolated from infections and 18 from colonization. The resistance profile pointed that 86.85% (33/38) of the isolates were multidrug-resistant, being three infection isolates, and two colonization isolates resistant to polymyxin B. All the isolates were able to produce biofilm and they had at least one of the investigated virulence genes on their molecular profile, but the bap gene was found in 100% of them. No clones were detected by ERIC-PCR. There was no correlation between biofilm formation and the resistance profile of the bacteria, neither to the molecular profile of the virulence genes. Thus, the ability of Acinetobacter spp. to form biofilm is probably related to the high frequency of virulence genes.202134550209
2318170.9998Distribution of pathogenic bacteria in lower respiratory tract infection in lung cancer patients after chemotherapy and analysis of integron resistance genes in respiratory tract isolates of uninfected patients. BACKGROUND: We studied the distribution of pathogenic bacteria in lower respiratory tract infection in lung cancer patients after chemotherapy and analyzed the integron resistance genes in respiratory tract isolates of uninfected patients. METHODS: Retrospective analysis was used to select sputum samples from 400 lung cancer patients after chemotherapy admitted in Fuyang People's Hospital from July 2017 to July 2019. Culture, isolation and identification of strains were conducted in accordance with the national clinical examination operating procedures. RESULTS: A total of 134 strains were identified. In 120 patients with pulmonary infection, 114 strains were cultured. Twenty strains of klebsiella pneumoniae were cultured in 280 patients without pulmonary infection. Among the 134 strains, the detection rate of gram-negative bacteria was 79.10%. The first four strains were Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Haemophilus influenzae. The gram-positive bacteria detection rate was 4.47%, mainly Staphylococcus aureus and Streptococcus. The fungus detection rate was 16.42%. The drug sensitivity results showed that the resistance rate of gram-negative bacillus to penicillin and cephalosporin was higher, and were more sensitive to carbapenem, piperacillin tazobactam and cefoperazone sulbactam. Gram-positive cocci were resistant to penicillin, macrolide and clindamycin, and sensitive to linezolid, vancomycin and rifampicin. All strains of fungal culture were candida albicans, which were sensitive to common antifungal drugs. Among the 20 strains of klebsiella pneumoniae cultured in sputum specimens of non-infected patients with lung cancer undergoing chemotherapy, 2 strains were integron-positive strains, and all of them were class I integrons. CONCLUSIONS: Lung cancer patients after chemotherapy have a high resistance to commonly used antimicrobial drugs, so it is necessary to detect the resistance of pathogenic microorganisms in clinical practice. The strains carried by patients with lung cancer without pulmonary infection during chemotherapy can isolate type I integrons, suggesting that the spread of drug resistance at gene level should be closely detected.202032944333
1705180.9998Formation ability and drug resistance mechanism of Klebsiella pneumoniae biofilm and capsule for multidrug-resistant. This study was to explore the formation ability of biofilm and capsule and the drug resistance mechanism for multidrug-resistant Klebsiella pneumoniae. firstly, 55 strains of K. pneumoniae were screened out from the body fluid specimens of the laboratory. The strains were drug-resistant, and the characteristics of clinical infections of these strains were analyzed. Secondly, all strains were tested for the presence of biofilms and capsules, and then the deoxyribonucleic acid (DNA) genomes of the strains extracted were detected using polymerase chain reaction (PCR) technology. Finally, the serotype genes and virulence genes of the strains were screened, and the relationship between these two genes and the formation of capsules and biofilms was analyzed and compared. A new generation of sequencing technology was applied to analyze the genome structure of K. pneumoniae, comparative genomics technology was adopted to analyze the drug resistance plasmids, and molecular cloning and other methods were utilized to clone the drug resistance-related genes. of the 55 strains of K. pneumoniae isolated clinically, 61.8% came from blood with a total number of 34 strains; 8 strains were from secretion specimens (accounting for 14.5% of the total); and 7 strains were from drainage fluid (accounting for 12.7% of the total), including 2 strains from pus, bile, and pleural fluid, respectively. The strains were tested by PCR, of which iroN virulence genes were the most (34 strains), accounting for 61.8%, followed by wabG and fimH (33 strains, accounting for 60% of the total), followed by magA, K2, K20, K1, and K57. The positive rates of the two virulence genes (fimH and wabG) were higher in positive strains of biofilm. The drug susceptibility results showed that ampicillin and amoxicillin were more resistant to capsule-positive strains than the capsule-negative strains. K. pneumoniae had been able to form a complete capsule and biofilm, the formation rate of biofilm was higher than that of the capsule, and there was an increasing trend. The two serotype genes (K20 and K2) accounted for relatively high proportions, and K. pneumoniae carried relatively more virulence genes (wabG and fimH), which may be closely related to the capsule production of K. pneumoniae. In addition, resistance-related genes were also transferred horizontally in different strains of bacteria, forming a wide range of drug resistance, which brought great difficulties to clinical work.202337953580
2326190.9998Frequency of Antimicrobial Resistance and Class 1 and 2 Integrons in Escherichia Coli Strains Isolated from Urinary Tract Infections. Resistance to antimicrobial compounds in E. coli strains is increasing. Integrons are mobile genetic elements that lead to the spread and transfer of antibiotic resistance genes in bacteria. The aim of the present study was to determine the frequency of class 1 and 2 integrons as well as the antimicrobial resistance in E.coli strains isolated from urinary tract infections (UTIs). A total of 100 clinical isolates of uropathogenic E. coli (UPEC) were collected from patients having UTIs. These strains were identified using biochemical tests. The antibiotic susceptibility patterns of the isolated bacteria were determined in accordance with the standard method recommended by the clinical and laboratory standards institute (CLSI). The presence of class 1 and 2 integrons was determined by PCR method. The most frequent antibiotic resistance was observed to ampicillin (72%), co-trimoxazole (66%), and nalidixic acid (62%). The highest sensitivity was seen to amikacine (11%) and gentamicin (20%). The multi-drug resistance (MDR) was observed in 80% of E. coli isolates. 70% and 3% of E. coli isolate possessed class 1 and 2 integrons, respectively. Our data suggest that the antimicrobial resistance to some antibiotics as well as the frequency of class 1 and 2 integrons is very high in E. coli strains. Moreover, class 1 integrons are correlated with resistance to ampicillin, gentamicin, ciprofloxacin, co-trimoxazole, and nalidixic acid. Therefore, it is very important to monitor integron-induced drug resistance, especially class 1 integron, in order to control the urinary tract infections causing by MDR E.coli strains.202033680029