Data on the prevalence and distribution of carbapenemase genes in Enterobacterales species isolated from clinical specimens in the center of Irans. - Related Documents




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93701.0000Data on the prevalence and distribution of carbapenemase genes in Enterobacterales species isolated from clinical specimens in the center of Irans. Carbapenem resistance in Enterobacterales is a major and persistent public health problem worldwide. In current research, we present data of 96 Enterobacterales species collected from a clinical hospital in Isfahan, Iran. The bacterial identification was performed by standard biochemical tests and API 20E methods. Agar disk diffusion assay was performed to determine the phenotypic antibiotic resistance of strains. Polymerase chain reaction (PCR) was carried out to detect carbapenemase genes. In this manuscript, multiple antimicrobial resistance phenotype such as multiple carbapenem resistance determinants were detected. The data would provide important information on distribution of carbapenemase genes of those pathogenic bacteria in Iran.202134568528
93110.9999Epidemiological 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
92820.9998Phenotypic and genotypic characterization of carbapenem encoding genes among carbapenem-resistant Gram-negative bacteria isolated from North Casablanca, Morocco. Carbapenem resistance genes in Gram-negative bacteria (CR-GNB) are a major cause of critical infections and are considered an urgent public health concern. The present study aimed to describe the prevalence of CR-GNB and the dissemination of extended-spectrum beta-lactamase (ESBL) and carbapenemase genes in clinical isolates from Casablanca, Morocco. Firstly, the strains were collected and identified using phenotypic and biochemical methods, then the antibiotic susceptibility was evaluated by the disc diffusion assay to screen isolates resistant to carbapenems. Secondly, three traditional methods, the carbapenem inactivation method, the modified Hodge, and the in-house carba-NP, were performed to predict the carbapenemase production by the included strains. Finally, conventional PCR was utilized to validate and detect the carbapenemase- and ESBL-related genes. Concerning the results, out of the identified 122 strains, 48 were CR isolates, including 30 Klebsiella pneumoniae, 13 Escherichia coli, and 5 Pseudomonas aeruginosa. Furthermore, these strains presented a high level of resistance. Moreover, the prediction of carbapenemase production by the phenotypic methods showed variable results. Also, the PCR analysis revealed a high occurrence of β-lactamase (ESBL and carbapenemase) genes in the included clinical strains, and most strains harbored multiple resistance genes. Our findings suggest that the three existing methods have some limitations, and a validation study is still necessary for the carbapenemase diagnostics.202540857960
167630.9998Evaluation of carbapenem resistance using phenotypic and genotypic techniques in Enterobacteriaceae isolates. BACKGROUND: Bacterial resistance to antibiotics is increasing worldwide. Antibiotic-resistant strains can lead to serious problems regarding treatment of infection. Carbapenem antibiotics are the final treatment option for infections caused by serious and life-threatening multidrug-resistant gram-negative bacteria. Therefore, an understanding of carbapenem resistance is important for infection control. In the study described herein, the phenotypic and genotypic features of carbapenem-resistant Enterobacteriaceae strains isolated in our hospital were evaluated. METHODS: In total, 43 carbapenem-resistant strains were included in this study. Sensitivity to antibiotics was determined using the VITEK(®)2 system. The modified Hodge test (MHT) and metallo-β-lactamase (MBL) antimicrobial gradient test were performed for phenotypic identification. Resistance genes IMP, VIM, KPC, NDM-1, and OXA-48 were amplified by multiplex PCR. RESULTS: The OXA-48 gene was detected in seven strains, and the NDM-1 gene in one strain. No resistance genes were detected in the remainder of strains. A significant correlation was observed between the MHT test and OXA-48 positivity, and between the MBL antimicrobial gradient test and positivity for resistance genes (p < 0.05). CONCLUSION: The finding of one NDM-1-positive isolate in this study indicates that carbapenem resistance is spreading in Turkey. Carbapenem resistance spreads rapidly and causes challenges in treatment, and results in high mortality/morbidity rates. Therefore, is necessary to determine carbapenem resistance in Enterobacteriaceae isolates and to take essential infection control precautions to avoid spread of this resistance.201526444537
86640.9998Opening 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.202031654790
100350.9998Molecular Surveillance and Dissemination of Klebsiella pneumoniae on Frequently Encountered Surfaces in South African Public Hospitals. Bacteria that cause life-threatening illnesses in humans are also capable of contaminating hospital surfaces, thus pose as a potential source of infection. This study aimed to investigate the prevalence, genetic diversity, virulence, and antibiotic resistance profile of Klebsiella pneumoniae in South Africa. In a nonoutbreak setting involving four public hospitals, 777 samples were collected in three different wards from 11 different sites. Phenotypic and genotypic methods were used for isolation and identification. The Kirby-Bauer disk-diffusion method was used to examine antibiotic resistance followed by the combination disk method to characterize extended-spectrum β-lactamases (ESBLs). Antibiotic resistance and virulence genes were screened using PCR and clonality was investigated using enterobacterial repetitive intergenic consensus (ERIC)-PCR. Seventy-five (10%) K. pneumoniae isolates were recovered. These isolates were obtained from all four hospitals and all three wards involved. However, only six frequently touched surfaces were contaminated. Thirty (40%) isolates were characterized as ESBLs showing high resistance to antibiotics and mostly harboring the bla(CTX-M) group one gene. Virulence genes were highly prevalent among all the isolates. ERIC-PCR showed that the isolates recovered from different sites within the same hospital were genetically similar. The study highlighted that K. pneumoniae can contaminate various surfaces and this persistence allows for the dissemination of bacteria within the hospital environment. The information from this study can assist hospitals to evaluate and improve current infection prevention and control interventions in place.202234170205
92160.9998Evaluation antibiotic resistance and presence of blaOXA-51, blaOXA-58 and blaOXA-23 genes in Acinetobacter baumannii strains via multiplex PCR. The resistance of Acinetobacter baumannii to most antibiotics is increasing. The presence of metallo-beta-lactamase and carbapenemase enzymes has led to the resistance of these bacteria to carbapenems as one of the major classes of broad-spectrum antibiotics and has raised concerns in human societies. This research evaluated the presence of bla(OXA-51), bla(OXA-58) and bla(OXA-23) genes in A. baumannii strains during a 12 months period. One hundred strains were isolated from the patients hospitalized in ICU of Ali Asghar and Shahid Rajaee trauma hospitals in Shiraz. Bacterial identity was determined by biochemical tests and antibiotic resistance was determined by disk diffusion method. The isolated strains were then evaluated in terms of carrying bla(OXA-23), bla(OXA-51) and bla(OXA-58) genes, using the multiplex PCR method. The results showed that A. baumannii was resistant to carbapenems but most strains were susceptible to tigecyclin and colistin. The majority of strains carried the bla(OXA-23) and bla(OXA-51) genes, but very few carried the bla (OXA-58) gene. The results revealed that the antibiotic resistance of A. baumannii is increasing, which causes a more outbreak of this organism.202134803000
230870.9998Trends 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
93280.9998Emergence of armA and rmtB genes among VIM, NDM, and IMP metallo-β-lactamase-producing multidrug-resistant Gram-negative pathogens. In the recent years, it has been noted that microorganisms with acquired resistance to almost all available potent antibiotics are increasing worldwide. Hence, the use of antibiotics in every clinical setup has to be organized to avoid irrational use of antibiotics. This study was aimed to establish the pattern of antibiotic sensitivity and relevance of antimicrobial resistance in aerobic Gram-negative bacilli. A total of 103 aerobic Gram-negative bacteria namely Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., Citrobacter koserii, Proteus spp., and Pseudomonas aeruginosa were collected from tertiary care centers around Chennai. Kirby-Bauer Disk Diffusion test and study for genes of cephalosporin, carbapenem, and aminoglycoside resistance were done. A descriptive analysis of the data on altogether 103 clinical urine isolates was performed. All strains showed susceptibility to colistin. The frequency of genes encoding 16S rRNA methylases armA and rmtB were 7.8% and 6.8%, respectively. Among metallo-β-lactamases, bla(VIM), bla(IMP), and bla(NDM-1) were detected in 6.8%, 3.8%, and 3.8%, respectively. One E. coli strain harbored bla(SIM-1) gene. Cumulative analysis of data suggested that 30% of the strains carried more than one resistance gene. The current research evidenced the increasing frequency of resistance mechanisms in India. Combined approach of antibiotic restriction, effective surveillance, and good infection control practices are essential to overcome antibiotic resistance.201828870092
93090.9998Isolation of Carbapenem and Colistin Resistant Gram-Negative Bacteria Colonizing Immunocompromised SARS-CoV-2 Patients Admitted to Some Libyan Hospitals. The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a devastating effect, globally. We describe, for the first time, the occurrence of carbapenem-resistant bacteria colonizing SARS-CoV-2 patients who developed hospital-associated infections with carbapenemase-producing, Gram-negative bacteria at some isolation centers of SARS-CoV-2 in the eastern part of Libya. In total, at first, 109 samples were collected from 43 patients, with the samples being recovered from oral (n = 35), nasal (n = 45), and rectal (n = 29) cavities. Strain identification was performed via matrix assisted laser desorption ionization-time of flight (MALDI-TOF). Antibiotic susceptibility testing was carried out on Mueller-Hinton agar, using the standard disk diffusion method. MIC determination was confirmed via E-TEST and microdilution standard methods. A molecular study was carried out to characterize the carbapenem and colistin resistance in Gram-negative bacterial strains. All of the positive results were confirmed via sequencing. Klebsiella pneumoniae (n = 32), Citrobacter freundii (n = 21), Escherichia coli (n = 7), and Acinetobacter baumannii (n = 21) were the predominant isolated bacteria. Gram-negative isolates were multidrug-resistant and carried different carbapenem resistance-associated genes, including NDM-1 (56/119; 47.05%), OXA-48 (15/119; 12.60%), OXA-23 (19/119; 15.96%), VIM (10/119; 8.40%), and the colistin resistance mobile gene mcr-1 (4/119; 3.36%). The overuse of antimicrobials, particularly carbapenem antibiotics, during the SARS-CoV-2 pandemic has led to the emergence of multidrug-resistant bacteria, mainly K. pneumoniae, A. baumannii, and colistin-resistant E. coli strains. Increased surveillance as well as the rational use of carbapenem antibiotics and, recently, colistin are required to reduce the propagation of multidrug-resistant strains and to optimally maintain the efficacy of these antibiotics. IMPORTANCE In this work, we describe, for the first time, the occurrence of carbapenem-resistant bacteria colonizing COVID-19 patients who developed hospital-associated infections with carbapenemase-producing, Gram-negative bacteria at some isolation centers of COVID-19 in the eastern part of Libya. Our results confirmed that the overuse of antimicrobials, such as carbapenem antibiotics, during the COVID-19 pandemic has led to the emergence of multidrug-resistant bacteria, mainly K. pneumoniae and A. baumannii, as well as colistin resistance.202337042782
938100.9998Molecular Identification of OXA Carbapenemase-Encoding Genes in Acinetobacter baumannii Isolated from Patients in Critical Care in Egypt. Background: The emergence of carbapenem-resistant Acinetobacter baumannii (CRAB) in hospitals, particularly within critical care units, has garnered substantial global concern. CRAB commonly arises from the degradation by various ß-lactamases. Objective: We aimed to assess OXA-type carbapenemases in clinical isolates of A. baumannii obtained from an Egyptian tertiary care facility. Patients and Methods: This study examined 25 distinct A. baumannii strains collected from various clinical samples of patients in intensive care unit. Bacterial identification was conducted utilizing both traditional methods and the Vitek2 system. Antibiotic resistance profiles were assessed according to the European Committee on Antimicrobial Susceptibility Testing standards using the Vitek2 Compact automated system. Additionally, multiplex real-time polymerase chain reaction was used to identify the presence of blaOXA23, blaOXA24, blaOXA51, and blaOXA58 carbapenemase genes. Colistin susceptibility was assessed utilizing the broth microdilution method. Results: Carbapenem resistance was identified in 100% of the studied isolates. The blaOXA51 gene was detected in all A. baumannii strains. The gene blaOXA23 was identified in 22 strains (88%), whereas blaOXA24 and blaOXA58 were present in 15 strains (60%). All isolates, except one, co-harbored two or more OXA encoding genes. Colistin resistance was detected in 4 of 25 strains (16%). Conclusion: Our findings demonstrate the widespread distribution of CRAB isolates that co-harbor multiple carbapenemase-encoding genes. Molecular epidemiological studies and the surveillance of antibiotic resistance profiles may aid in identifying and tracing the origins of resistant bacteria, thereby limiting their spread.202539602244
863110.9998Colistin-resistance genes in Escherichia coli isolated from patients with urinary tract infections. BACKGROUND: The incidence of antimicrobial resistance is alarmingly high because it occurs in humans, environment, and animal sectors from a "One Health" viewpoint. The emergence of plasmid-carried mobile colistin-resistance (MCR) genes limits the efficacy of colistin, which is the last-line treatment for multidrug resistance (MDR) against gram-negative infections. OBJECTIVES: The current study aimed to investigate emergence of colistin-resistance (MCR 1-5) genes in E. coli isolated from patients with urinary tract infections (UTIs) in Jordan. METHODS: E. coli (n = 132) were collected from urine specimens. The E. coli isolated from human UTI patients were examined the resistance to colistin based on the presence of MCR (1-5). All isolates were tested against 20 antimicrobials using the standard disk diffusion method. The broth microdilution technique was used to analyze colistin resistance. In addition, the MCR (1-5) genes were detected using multiplex PCR. RESULTS: Out of the 132 isolates, 1 isolate was colistin-resistant, having a minimum inhibitory concentration of 8 μg/mL and possessing MCR-1. All the E. coli isolates showed high resistance to penicillin (100%), amoxicillin (79.55%), cephalexin (75.76%), nalidixic acid (62.88%), tetracycline (58.33%), or cefepime (53.79). CONCLUSION: To our knowledge, this is the first report on the presence of plasmid-coded MCR-1 in E. coli from a patient with UTIs in Jordan. This is a problematic finding because colistin is the last-line drug for the treatment of infections caused by MDR gram-negative bacteria. There is a crucial need to robustly utilize antibiotics to control and prevent the emergence and prevalence of colistin-resistance genes.202438865304
1700120.9998The Prevalence of Multidrug-Resistant Enterobacteriaceae among Neonates in Kuwait. Increasing numbers of neonates with serious bacterial infections, due to resistant bacteria, are associated with considerable morbidity and mortality rates. The aim of this study was to evaluate the prevalence of drug-resistant Enterobacteriaceae in the neonatal population and their mothers in Farwaniya Hospital in Kuwait and to determine the basis of resistance. Rectal screening swabs were taken from 242 mothers and 242 neonates in labor rooms and wards. Identification and sensitivity testing were performed using the VITEK(®) 2 system. Each isolate flagged with any resistance was subjected to the E-test susceptibility method. The detection of resistance genes was performed by PCR, and the Sanger sequencing method was used to identify mutations. Among 168 samples tested by the E-test method, no MDR Enterobacteriaceae were detected among the neonates, while 12 (13.6%) isolates from the mothers' samples were MDR. ESBL, aminoglycosides, fluoroquinolones, and folate pathway inhibitor resistance genes were detected, while beta-lactam-beta-lactamase inhibitor combinations, carbapenems, and tigecycline resistance genes were not. Our results showed that the prevalence of antibiotic resistance in Enterobacteriaceae obtained from neonates in Kuwait is low, and this is encouraging. Furthermore, it is possible to conclude that neonates are acquiring resistance mostly from the environment and after birth but not from their mothers.202337189605
927130.9998Prevalence of carbapenemase-producing organisms at the Kidney Center of Rawalpindi (Pakistan) and evaluation of an advanced molecular microarray-based carbapenemase assay. AIM: A DNA microarray-based assay for the detection of antimicrobial resistance (AMR) genes was used to study carbapenemase-producing organisms at the Kidney Center of Rawalpindi, Pakistan. METHODS: The evaluation of this assay was performed using 97 reference strains with confirmed AMR genes. Testing of 7857 clinical samples identified 425 Gram-negative bacteria out of which 82 appeared carbapenem resistant. These isolates were analyzed using VITEK-2 for phenotyping and the described AMR assay for genotyping. RESULTS: The most prevalent carbapenemase gene was blaNDM and in 12 isolates we detected two carbapenemase genes (e.g., blaNDM/blaOXA-48). CONCLUSION: Our prevalence data from Pakistan show that - as in other parts of the world - carbapenemase-producing organisms with different underlying resistance mechanisms are emerging, and this warrants intensified and constant surveillance.201829938540
867140.9998Epidemiology and Mechanism of Drug Resistance of Multidrug-Resistant Klebsiella Pneumoniae Isolated from Patients with Urinary Tract Infection in Beijing Teaching Hospital, China. PURPOSE: Klebsiella pneumoniae is an important pathogenic bacterium in causing urinary tract infection. With the overuse of antibiotics, bacteria resistant to quinolones combined with carbapenems are increasing. In this study, we investigated the epidemiology, molecular characteristics, drug resistance of multidrug-resistant Klebsiella pneumoniae (MDR-KPN) isolated from urine samples. It provides theoretical basis for the treatment of urinary tract infection by clinicians. PATIENTS AND METHODS: Fifty-one strains of Klebsiella pneumonia were obtained from urine samples collected between 2012 and 2017 in total. All the strains are multi-drug resistant bacteria. This paper used multilocus sequence typing (MLST) to determine molecular epidemiological typing. We performed antimicrobial susceptibility testing and investigated quinolones and carbapenems resistance genes. RESULTS: The strains which we collected were resistant to ciprofloxacin and Levofloxacin. In an epidemiological analysis using MLST, 86.27% (44/51) of isolates were confirmed to be ST11. The main carbapenem resistance gene was KPC-19, 78.43(40/51). Among the quinolone resistance genes, the major resistance genes were aac(6')-Ib-cr, oqxA and oqxB. CONCLUSION: The main molecular epidemiological types we detected was ST11. The main resistance gene of carbapenems was KPC-19. The quinolone resistance genes are mainly aac(6')-Ib-cr, oqxA and oqxB. The experimental results can help control the use of quinolones and carbapenems, and we could provide rational drug use basis for clinicians to treat urinary tract infection. For MDR-KPN, a combination of multiple antibiotics is necessary.202539803309
860150.9998Investigation of Plasmid-Mediated Colistin Resistance Genes (mcr-1-8) in Enterobacterales Isolates. Background The escalating global rise in multidrug-resistant gram-negative bacteria presents an increasingly substantial threat to patient safety. Over the past decade, carbapenem-resistant Enterobacterales (CRE) have emerged as one of the most critical pathogens in hospital-acquired infections, notably within intensive care units. Colistin has become one of the last-resort antimicrobial agents utilized to combat infections caused by CRE. However, the use of colistin has been accompanied by a notable increase in the prevalence of colistin-resistant bacteria. This study aimed to investigate plasmid-mediated colistin resistance genes ranging from mcr-1 to mcr-8 among members of the Enterobacterales order. Materials and methods This prospective study was conducted in the microbiology laboratory of Afyonkarahisar Health Sciences University Health Research and Practice Center between May 1, 2021 and July 31, 2022. A total of 2,646 Enterobacterales isolates were obtained from all culture-positive clinical samples sent from various clinics. Of these, 79 isolates exhibiting resistance to carbapenem antibiotics were included in the study. Among the 79 isolates, the presence of mcr-1 to mcr-8 genes was investigated in 27 isolates that were shown to be resistant to colistin. The identification of bacteria at the species level and antibiotic susceptibility tests were conducted using the VITEK 2 automated system (bioMérieux, USA). Colistin resistance among Enterobacterales strains exhibiting carbapenem resistance was evaluated using the broth microdilution technique (ComASP™ Colistin, Liofilchem, Italy), in accordance with the manufacturer's instructions. Results In our in vitro investigations, the minimum inhibitory concentration (MIC) values for meropenem were determined to be >8 µg/ml, whereas for colistin, the MIC50 value was >16 µg/ml and the MIC90 value was 8 µg/ml. A total of 27 colistin-resistant strains were identified among the 79 carbapenem-resistant Enterobacterales strains analyzed. The most prevalent agent among colistin-resistant strains was Klebsiella pneumoniae (K. pneumoniae), representing 66.7% of the isolates. This was followed by Proteus mirabilis (P. mirabilis) with 29.6% and Escherichia coli (E. coli) with 3.7%. The colistin resistance rate among carbapenem-resistant strains was found to be 34.2%, with colistin MIC values in strains tested by the broth microdilution method ranging from 4 to >16 µg/ml concentrations. In polymerase chain reaction (PCR) studies, the mcr-1 gene region was successfully detected by real-time PCR in the positive control isolate. Nevertheless, none of the gene regions from mcr-1 to mcr-8 were identified in our study investigating the presence of plasmid-mediated genes using a multiplex PCR kit. Conclusion Although our study demonstrated the presence of increased colistin resistance rates in carbapenem-resistant Enterobacterales isolates, it resulted in the failure to detect genes from mcr-1 to mcr-8 by the multiplex PCR method. Therefore, it is concluded that the colistin resistance observed in Enterobacteriaceae isolates in our region is not due to the mcr genes screened, but to different resistance development mechanisms.202438957246
935160.9998Evaluating the Saliva of Burn ICU Patients for Resistant Infections Harbor Metallo-β-Lactamase Genes. Pseudomonas aeruginosa and Acinetobacter baumannii are the bacteria which increasingly account for nosocomial infections. Due to high virulence, the rate of Multi-Drug Resistance (MDR) and limited availability of new agents, these infections create significant clinical burdens, making it important to identify the possible sources of their occurrence. The aim of this study was to assess non-lactose fermenting bacteria and their metallo-β-lactamase (MBLs) genes expression in the Burn Intensive Care Unit (BICU) patients' saliva samples. This cross-sectional study was conducted from 2017 to 2018 on 124 saliva samples of BICU patients. Identified isolates were evaluated for drug susceptibility by disc diffusion method. MBLs production isolates were detected by Modified Hodge test and Imipenem-EDTA Combined disk. MBLs related genes were evaluated by polymerase chain reaction (PCR). A total of 86 Gram negative non-lactose fermenting bacteria (38; A. baumannii) and (48; P. aeruginosa), were detected. All of the A. baumannii isolates were resistant to Carbapenems, while more than 90% of them were sensitive to Colistin. However, the highest sensitivity in P. aeruginosa isolates was related to Carbapenems and Colistin. More than 95% of A. baumannii and 32% of P. aeruginosa were detected MDR. MBLs production was confirmed in 9 (33.33%) P. aeruginosa and 18 (66.67%) A. baumannii isolates. The blaVIM was the most prevalent gene, while this gene was detected in all of MBLs positive strains. This study confirmed the prevalence of carbapenemase producer Gram-negative bacilli in the saliva of BICU patients. The results of the present study provide a new data set about saliva infection source that could lead to the proper antibiotic regimen and better control of drug resistance.202031930340
1675170.9998Phenotypic and genetic extended spectrum beta lactamase profiles of bacterial isolates from ICU in tertiary level hospital in Kenya. BACKGROUND: Bacterial infections in the Intensive Care Units are a threat to the lives of critically ill patients. Their vulnerable immunity predisposes them to developing bacteria-associated sepsis, deteriorating their already fragile health. In the face of increasing antibiotics resistance, the problem of bacterial infection in ICU is worsening. Surveillance of bacterial infections in ICUs and drug resistance will help to understand the magnitude of the problem it poses and inform response strategies. We assessed bacterial infections in ICU setting by identifying prevalent Gram-negative bacterial species and characterized their antibiotic susceptibility patterns. METHODS: Cross-sectional samples collected from Kenyatta National Hospital ICU between January and June 2021 were cultured and phenotypic identification of culture-positive samples performed using VITEK 2. Antibiotic susceptibility patterns were determined based on Antimicrobial Susceptibility Testing (AST) results. Cephalosporin-resistant Gram-negative bacteria were assessed by PCR to detect the presence of ESBL genes including ( (bla) CTX-M, (bla) SHV, (bla) TEM, (bla) OXA). RESULTS AND DISCUSSION: Out of the 168 Gram-negative isolates, Acinetobacter baumanii was the most abundant (35%). Other isolates that were present at frequencies more than 15% are Klebsiella pneumoniae and Escherichia. coli. A. baumaniii is known to be a notorious bacterium in ICU due to its multidrug resistance nature. Indeed, A. baumanii isolates from Kenyatta National Hospital showed significantly high level of phenotypic resistance. Concordant with the high level of phenotypic resistance, we found high carriage of the ESBL genes among the isolates analysed in this study. Moreover, majority of isolates harboured all the four ESBL genes. CONCLUSION: A high rate of phenotypic and genetic resistance was detected among the tested isolates. Resistance to cephalosporins was primarily driven by acquisition of the ESBL genes. The high prevalence rate of ESBL genes in ICU bacterial isolates shown in this study has a important implication for ICU patient management and general antibiotics use.202339850338
859180.9998Analysis 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
933190.9998Molecular characterization and diversity of carbapenemases in Gram-negative bacteria in Libyan hospitals. INTRODUCTION: Antimicrobial resistance has become a major threat to public health, especially in developing countries, due to the uncontrolled consumption of antibiotics. This study aims to characterize antibiotic resistance genes in different bacteria recovered in different healthcare facilities in Libya. METHODOLOGY: 379 samples were recovered from various sources from different sites. 210 samples were able to grow on culture media. 133 Gram-negative carbapenem-resistant strains were recovered from clinical specimens (n = 64), and hospital environments (n = 69). Antibiotic susceptibility tests were performed to select carbapenem-resistant strains. Colistin resistance was tested by the UMIC method to determine the minimum inhibitory concentration. RT-PCR was conducted to detect the incidence of carbapenemases-encoding genes. RESULTS: Gram-negative bacteria showed a low susceptibility to carbapenems. Molecular investigations indicated that NDM-1 was the most prevalent in Enterobacteriaceae isolated from patients and hospital environment (n = 26, n = 41), followed by blaOXA-48 (n = 16, n = 15) and blaVIM (n = 3) from patients and blaKPC (n = 1) from hospital environment. Concerning A. baumannii, blaOXA-23 was detected in strains isolated from patients (n = 8) and hospital environment (n = 6), followed by blaNDM (n = 9) from patients and one from hospital environment. Carbapenem resistance in P. aeruginosa was encoded by modification in OprD encoding gene, such as IS (ISpa26), polymorphism, and a premature stop codon. CONCLUSIONS: Several carbapenem resistant Gram-negative bacteria were identified by the expression of different carbapenemases and the alteration of OprD.202540720466