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140500.9881The threat of carbapenem resistance in Eastern Europe in patients with decompensated cirrhosis admitted to intensive care unit. BACKGROUND: Multidrug-resistant organisms are an increasing concern in patients with decompensated cirrhosis. AIM: We aimed to evaluate the prevalence of infections with carbapenem-resistant Enterobacteriaceae in patients with decompensated cirrhosis. METHODS: Patients with decompensated cirrhosis admitted to ICU were included. The isolated Enterobacteriaceae strains were tested for carbapenemase-producing genes using the Roche LightMix® Modular VIM/IMP/NDM/GES/KPC/OXA48-carbapenemase detection kit. RESULTS: 48 culture-positive infections were registered in 75 patients with acutely decompensated cirrhosis. Thirty patients contracted a second infection. 46% of bacteria isolated at admission and 60% of bacteria responsible for infections identified during ICU-stay were multiresistant. ESBL+ Enterobacteriaceae were predominant at admission, while carbapenem-resistance was dominant in both Enterobacteriaceae and Non-Fermenting-Gram-Negative Bacteria responsible for infections diagnosed during hospitalisation. OXA 48 or KPC type carbapenemases were present in 30% of the analyzed Enterobacteriaceae and in 40% of the phenotypically carbapenem-resistant Klebsiella pneumoniae strains. The length of ICU stay was a risk-factor for a second infection (p=0.04). Previous carbapenem usage was associated with occurence of infections with carbapenem-resistant Gram-negative bacteria during hospitalization (p=0.03). CONCLUSION: The prevalence of infections with carbapenem-resistant Enterobacteriaceae is high in patients with decompensated cirrhosis admitted to ICU. Carbapenemase-producing genes in Enterobacteriaceae in our center are bla(OXA-48) and bla(KPC).202235732546
147610.9879Evaluation of the BioFire FilmArray Pneumonia Panel for rapid detection of respiratory bacterial pathogens and antibiotic resistance genes in sputum and endotracheal aspirate specimens. OBJECTIVES: The performance of the investigational-use-only version of the BioFire FilmArray Pneumonia Panel (FA-Pneumo), a high-order nested multiplex PCR, was evaluated for the detection of typical respiratory bacterial pathogens and antibiotic resistance genes in sputa and endotracheal aspirate (ETA) specimens. METHODS: Thirty-one sputa and 69 ETA specimens were analyzed. The diagnostic performance of FA-Pneumo was assessed using routine microbiological methods as the reference standard. RESULTS: Overall sensitivity and specificity for organism detection using FA-Pneumo were 98.5% and 76.5%, respectively. The sensitivity for each pathogen was 100%, except for Klebsiella aerogenes, and the range of specificity was 83.3-99.0%. FA-Pneumo detected antimicrobial resistance genes in 17 out of 18 specimens (94.4%) that were resistant by antimicrobial susceptibility testing. FA-Pneumo additionally detected 25 resistance genes in 22 specimens, and sequencing for the presence of resistance genes confirmed the majority of these results (20/25, 80%). Semi-quantitative analysis of bacterial nucleic acid amounts by FA-Pneumo revealed that 88.2% of the identified bacteria (67/76) with ≥10(6) copies/ml also gave culture-positive results with significant amounts of bacteria. CONCLUSIONS: FA-Pneumo is a rapid test with high sensitivity for the detection of bacteria and antimicrobial resistance genes in sputum and ETA specimens and could aid in determining antibiotic therapy.202032179139
142820.9874Carbapenem-resistant Gram-negative bacteria associated with catheter-related bloodstream infections in three intensive care units in Egypt. We aimed to identify the carbapenem-resistant Gram-negative bacteria (GNB) causing catheter-related bloodstream infections (CRBSI) in intensive care units (ICU) in a tertiary care Egyptian hospital, to study their resistance mechanisms by phenotypic and genetic tests, and to use ERIC-PCR for assessing their relatedness. The study was conducted over 2 years in three ICUs in a tertiary care hospital in Egypt during 2015-2016. We identified 194 bloodstream infections (BSIs); 130 (67.01%) were caused by GNB, of which 57 were isolated from CRBSI patients (73.84%). Identification of isolates was performed using conventional methods and MALDI-TOF MS. Antimicrobial susceptibility testing (AST) was done by disc diffusion following CLSI guidelines. Phenotypic detection of carbapenemases enzymes activity was by modified Hodge test and the Carba-NP method. Isolates were investigated for the most common carbapenemases encoding genes bla(KPC), bla(NDM), and bla(OXA-48) using multiplex PCR. Molecular typing of carbapenem-resistant isolates was done by ERIC-PCR followed by sequencing of common resistance genes. The overall rate of CRBSI in our study was 3.6 per 1000 central venous catheter (CVC) days. Among 57 Gram-negative CRBSI isolates, Klebsiella pneumoniae (K. pneumoniae) was the most frequently isolated (27/57; 47.4%), of which more than 70% were resistant to Meropenem. Phenotypic tests for carbapenemases showed that 37.9% of isolates were positive by modified Hodge test and 63.8% by Carba-NP detection. Multiplex PCR assay detected the bla(NDM) in 28.6% of the isolates and bla(KPC) in 26.8%, bla(NDM) and bla(KPC) were detected together in the same isolate in 5.6%, while bla(OXA-48)-like were not detected. ERIC-PCR detected limited genetic relatedness between K. pneumoniae isolates. Elevated resistance rates were observed to all antibiotics including carbapenems among K. pneumoniae isolates causing CRBSI. ERIC-PCR showed that the resistant isolates were mainly polyclonal. Our results call for reinforcement of antimicrobial stewardship and measures to prevent CRBSI.201829936619
142630.9872Phenotypic and genotypic detection of carbapenemase production among gram negative bacteria isolated from hospital acquired infections. OBJECTIVES: To identify the carbapenemase producing Gram-negative bacteria (GNB) by phenotypic methods and to confirm the presence of resistant genes using real-time polymerase chain reaction (PCR). METHODS: This was a prospective study carried out at the Department of Microbiology, Sri Venkata Sai Medical College and Hospital, Mahabubnagar, India, from March 2018-2021. All samples were screened for carbapenem resistance by disc diffusion method and the VITEK(®)2 compact system (bioMérieux, France). Detection of carbapenemase was carried out using RAPIDEC(®)CARBA NP test (Biomeriux Private Limited, South Delhi, India), screening for metallo-β-lactamases (MBL) was carried out by double disk synergy test (DDST), and genotypic characterization by real-time PCR. RESULTS: Among the 1093 Gram-negative bacilli identified, 220 (17.0%) were resistant to carbapenems by both tested methods. Carbapenemase detection using the RAPIDEC(®)CARBA NP test indicated that 207 (94.0%) were carbapenemase producers, of which 189 (91.2%) were MBL producers. The most common carbapenemase genes identified were New Delhi metallo-β-lactamase (NDM; 47.3%), followed by the co-existence of genes in combination of NDM, with Verona integron-mediated metallo-β-lactamase (VIM; 39.6%), VIM and oxacillin hydrolyzing enzymes-48 (OXA-48; 4.3%), and OXA-48 (1.4%).No gene of active on imipenem, Klebsiella pneumonia carbapenemase, VIM, or OXA-48 alone was detected. CONCLUSION: This study suggests routine carbapenem resistance testing among multi-drug resistant-GNBs, as most of these infections occur in hospitals. In addition, there is a possibility that these highly antibiotic-resistant genes could spread to other bacteria resulting in further dissemination.202235256490
145440.9872OCCURRENCE OF AMINOGLYCOSIDES RESISTANCE GENES ACC(6)-IB AND ACC(3)-II AMONG GRAM-NEGATIVE ISOLATES CAUSING URINARY TRACT INFECTION IN PEDIATRIC PATIENTS, NAJAF, IRAQ. OBJECTIVE: The aim: The aim of the study was to detect the antimicrobial susceptibility patterns and frequency of aminoglycosides resistance genes of Gram-negative bacteria isolated from pediatric patient with UTI. PATIENTS AND METHODS: Materials and methods: The study has been performed with a total of 500 urine specimens collected from pediatric patients under the age of 18 year suspected with UTI, admitted to hospitals in Al-Najaf province/Iraq during the period from November 2018 to March 2019. RESULTS: Results: A total of 500 urine specimens had been tested, 120 (24%) had signifficant bacteriuria, while there 380 (76%) had non-signi!cant bacteriuria. Escherichia coli represent about 70 (68.2%) followed by followed by 23 (22.5%) K. pneumoniae, 5 (4.9%) P. aeruginosa, 2 (1.9%) Proteus spp., 1 (0.9%) Enterobacter spp. and 1 (0.9%) Oligella uratolytic. The antimicrobial susceptibility profile of 102 Gram-negative isolates, revealed that 59 (58%) were multidrug resistant (MDR) and 38(37%) were extensive drug resistant (XDR). The PCR results of aminoglycosides resistance showing that 23 (74.1%) Gram-negative isolates had acc(6')-Ib gene and 12 (38.7%) Gram-negative isolates acc(3')-II gene. CONCLUSION: Conclusions: A high frequency of multi-drug resistance and extensive-drug resistance of isolates were recognized, and an alarming percentage of amino-glycosides resistance to acc(6')-Ib and acc(3')-II.202337010165
145250.9870Characterization of carbapenem-resistant Gram-negative bacteria from Tamil Nadu. Carbapenem resistance is disseminating worldwide among Gram-negative bacteria. The aim of this study was to identify carbapenem-resistance level and to determine the mechanism of carbapenem resistance among clinical isolates from two centres in Tamil Nadu. In the present study, a total of 93 Gram-negative isolates, which is found to be resistant to carbapenem by disk diffusion test in two centres, were included. All isolates are identified at species level by 16S rRNA sequencing. Minimal inhibitory concentrations (MICs) of isolates for Meropenem were tested by agar dilution method. Presence of blaOXA, blaNDM, blaVIM, blaIMP and blaKPC genes was tested by PCR in all isolates. Amplicons were sequenced for confirmation of the genes. Among 93 isolates, 48 (%52) were Escherichia coli, 10 (%11) Klebsiella pneumoniae, nine (%10) Pseudomonas aeruginosa. Minimal inhibitory concentration results showed that of 93 suspected carbapenem-resistant isolates, 27 had meropenem MICs ≥ 2 μg/ml. The MIC range, MIC50 and MIC90 were < 0.06 to >128 μg/ml, 0.12 and 16 μg/ml, respectively. Fig. 1 . Among meropenem-resistant isolates, E. coli were the most common (9/48, 22%), followed by K. pneumoniae (7/9, 77%), P. aeruginosa (6/10, 60%), Acinetobacter baumannii (2/2, 100%), Enterobacter hormaechei (2/3, 67%) and one Providencia rettgeri (1/1, 100%). PCR results showed that 16 of 93 carried blaNDM, three oxa181, and one imp4. Among blaNDM carriers, nine were E. coli, four Klebsiella pneumoniae, two E. hormaechei and one P. rettgeri. Three K. pneumoniae were OXA-181 carriers. The only imp4 carrier was P. aeruginosa. A total of seven carbapenem-resistant isolates were negatives by PCR for the genes studied. All carbapenem-resistance gene-positive isolates had meropenem MICs >2 μg/ml. Our results confirm the dissemination of NDM and emergence of OXA-181 beta-lactamase among Gram-negative bacteria in South India. This study showed the emergence of NDM producer in clinical isolates of E. hormaechei and P. rettgeri in India.201626198414
143060.9870Prevalence of multidrug-resistant Gram-negative bacteria from blood cultures and rapid detection of beta-lactamase-encoding genes by multiplex PCR assay. INTRODUCTION: This study aimed to determine the prevalence of multidrug-resistant Gram-negative bacteria (GNB) from blood cultures in a tertiary-care hospital and the multiplex PCR assay's ability to detect resistance genes. METHODS: A total of 388 GNB isolates obtained from hospitalized patients between November 2019 and November 2021 were included in the study. Antimicrobial susceptibility testing was done by VITEK 2 system and broth microdilution method. Beta-lactamase-encoding genes were detected by multiplex PCR assays, BioFire-Blood Culture Identification 2 (BCID2) panel (bioMérieux, France). Extended-spectrum beta-lactamases (ESBLs) were detected phenotypically with VITEK AST-GN71 card (bioMérieux, France). The isolates of GNB were classified into multidrug-resistant, extensively-drug-resistant, and pandrug-resistant categories, and their prevalence and distribution in different wards, including coronavirus diseases 2019 (COVID-19) intensive care units (ICU), were calculated. RESULTS: Results revealed that all isolates of Acinetobacter baumannii and Pseudomonas aeruginosa were multidrug-resistant as well as 91.6% of Enterobacter cloacae, 80.6% of Proteus mirabilis, and 76.1% of Klebsiella pneumoniae, respectively. In fermentative bacteria, bla(OXA-48-like) (58.1%), bla(NDM) (16.1%), bla(KPC) (9.7%) and bla(VIM) (6.5%) genes were detected. More than half of Enterobacter cloacae (58.3%) and Klebsiella pneumoniae (53.7%) produced ESBLs. Among non-fermenters, the bla(NDM) gene was carried by 55% of Pseudomonas aeruginosa and 19.5% of Acinetobacter baumannii. In the COVID-19 ICU, Acinetobacter baumannii was the most common isolate (86.1%). CONCLUSIONS: This study revealed high proportions of multidrug-resistant blood isolates and various underlying resistance genes in Gram-negative strains. The BCID2 panel seems to be helpful for the detection of the most prevalent resistance genes of fermentative bacteria.202238021186
148870.9870Evaluation of an automated rapid diagnostic assay for detection of Gram-negative bacteria and their drug-resistance genes in positive blood cultures. We evaluated the performance of the Verigene Gram-Negative Blood Culture Nucleic Acid Test (BC-GN; Nanosphere, Northbrook, IL, USA), an automated multiplex assay for rapid identification of positive blood cultures caused by 9 Gram-negative bacteria (GNB) and for detection of 9 genes associated with β-lactam resistance. The BC-GN assay can be performed directly from positive blood cultures with 5 minutes of hands-on and 2 hours of run time per sample. A total of 397 GNB positive blood cultures were analyzed using the BC-GN assay. Of the 397 samples, 295 were simulated samples prepared by inoculating GNB into blood culture bottles, and the remaining were clinical samples from 102 patients with positive blood cultures. Aliquots of the positive blood cultures were tested by the BC-GN assay. The results of bacterial identification between the BC-GN assay and standard laboratory methods were as follows: Acinetobacter spp. (39 isolates for the BC-GN assay/39 for the standard methods), Citrobacter spp. (7/7), Escherichia coli (87/87), Klebsiella oxytoca (13/13), and Proteus spp. (11/11); Enterobacter spp. (29/30); Klebsiella pneumoniae (62/72); Pseudomonas aeruginosa (124/125); and Serratia marcescens (18/21); respectively. From the 102 clinical samples, 104 bacterial species were identified with the BC-GN assay, whereas 110 were identified with the standard methods. The BC-GN assay also detected all β-lactam resistance genes tested (233 genes), including 54 bla(CTX-M), 119 bla(IMP), 8 bla(KPC), 16 bla(NDM), 24 bla(OXA-23), 1 bla(OXA-24/40), 1 bla(OXA-48), 4 bla(OXA-58), and 6 blaVIM. The data shows that the BC-GN assay provides rapid detection of GNB and β-lactam resistance genes in positive blood cultures and has the potential to contributing to optimal patient management by earlier detection of major antimicrobial resistance genes.201424705449
140680.9870Multicentre study of the burden of multidrug-resistant bacteria in the aetiology of infected diabetic foot ulcers. BACKGROUND: Infected diabetic foot ulcer (IDFU) is a public health issue and the leading cause of non-traumatic limb amputation. Very few published data on IDFU exist in most West African countries. OBJECTIVE: The study investigated the aetiology and antibacterial drug resistance burden of IDFU in tertiary hospitals in Osun state, Nigeria, between July 2016 and April 2017. METHODS: Isolates were cultured from tissue biopsies or aspirates collected from patients with IDFU. Bacterial identification, antibiotic susceptibility testing and phenotypic detection of extended-spectrum beta-lactamase and carbapenemase production were done by established protocols. Specific resistance genes were detected by polymerase chain reaction. RESULTS: There were 218 microorganisms isolated from 93 IDFUs, comprising 129 (59.2%) Gram-negative bacilli (GNB), 59 (27.1%) Gram-positive cocci and 29 (13.3%) anaerobic bacteria. The top five facultative anaerobic bacteria isolated were: Staphylococcus aureus (34; 15.6%), Escherichia coli (23; 10.6%), Pseudomonas aeruginosa (20; 9.2%), Klebsiella pneumoniae (19; 8.7%) and Citrobacter spp. (19; 8.7%). The most common anaerobes were Bacteroides spp. (7; 3.2%) and Peptostreptococcus anaerobius (6; 2.8%). Seventy-four IDFUs (80%) were infected by multidrug-resistant bacteria, predominantly methicillin-resistant S. aureus and GNB producing extended-spectrum β-lactamases, mainly of the CTX-M variety. Only 4 (3.1%) GNB produced carbapenemases encoded predominantly by bla (VIM). Factors associated with presence of multidrug-resistant bacteria were peripheral neuropathy (adjusted odds ratio [AOR] = 4.05, p = 0.04) and duration of foot infection of more than 1 month (AOR = 7.63, p = 0.02). CONCLUSION: Multidrug-resistant facultative anaerobic bacteria are overrepresented as agents of IDFU. A relatively low proportion of the aetiological agents were anaerobic bacteria.202133824857
141190.9869Detection and characterization of carbapenem resistant Gram-negative bacilli isolates recovered from hospitalized patients at Soba University Hospital, Sudan. BACKGROUND: Antimicrobial resistance (AMR) poses a complex threat to global health security and universal health coverage. Recently, nosocomial infections with carbapenemase-producing Gram-negative bacilli (GNB) is increasing worldwide. We report the molecular characterization and detection of genes associated with carbapenemase producing Gram negative bacteria isolated from hospitalized patients at Soba University Hospital (SUH) in Khartoum State, Sudan. RESULTS: Between October 2016 and February 2017, a total of 206 GNB clinical specimens were collected from hospitalized patients in SUH. Of 206 carbapenem resistance isolates, 171 (83 %) were confirmed as phenotypically resistant and 121 (58.7 %) isolates harboured one or more carbapenemase genes. New Delhi metallo-β-lactamase (NDM) types were the most predominant genes, blaNDM 107(52 %), followed by blaIMP 7 (3.4 %), blaOXA-48 5(2.4 %) and blaVIM 2 (0.9 %). Co-resistance genes with NDM producing GNB were detected in 87 (81.3 %) of all blaNDM producing isolates. NDM-1 was the most frequent subtype observed in 75 (70 %) blaNDM producing isolates. The highest percentage of resistance was recorded in ampicillin (98 %), cephalexin (93.5 %) amoxicillin clavulanic acid (90 %), cefotaxime (89.7 %), ceftriaxone (88.4 %), ceftazidime (84.2 %), sulfamethoxazole-trimethoprim (78.4 %) and nitrofurantoin (75.2 %), aztreonam (66 %) and temocillin (64 %). A close correlation between phenotypic and carbapenemase genes detection in all GNB was observed. CONCLUSIONS: The frequency of carbapenemase producing bacilli was found to be high in SUH. NDM was found to be the most prevalent carbapenemase gene among clinical isolates. Close surveillance across all hospitals in Sudan is required. The relative distribution of carbapenemase genes among GNB in nosocomial infections in Africa needs to be defined.202133947325
1487100.9869Potential impact of a microarray-based nucleic acid assay for rapid detection of Gram-negative bacteria and resistance markers in positive blood cultures. We evaluated the Verigene Gram-negative blood culture (BC-GN) test, a microarray that detects Gram-negative bacteria and several resistance genes. A total of 102 positive blood cultures were tested, and the BC-GN test correctly identified 97.9% of the isolates within its panel. Resistance genes (CTX-M, KPC, VIM, and OXA genes) were detected in 29.8% of the isolates, with positive predictive values of 95.8% (95% confidence interval [CI], 87.7% to 98.9%) in Enterobacteriaceae and 100% (95% CI, 75.9% to 100%) in Pseudomonas aeruginosa and negative predictive values of 100% (95% CI, 93.9% to 100%) and 78.6% (95% CI, 51.0% to 93.6%), respectively.201424478405
1429110.9869Detection of blaKPC and blaGES Carbapenemase Genes in Klebsiella pneumoniae Isolated from Hospitalized Patients in Kashan, Iran. INTRODUCTION: Klebsiella pneumoniae carbapenemase (KPC)-producing bacteria are among the highly antimicrobial resistant gram negative bacteria and infections due to them are an increasingly major health problem worldwide. METHODS: In this study we have detected the blaKPC and blaGES carbapenemase genes in Klebsiella pneumoniae isolated from hospitalized patients in Kashan, Iran. In a cross-sectional study, a total of 181 K. pneumoniae isolates were recovered from clinical specimens during November 2013 to October 2014. RESULT: Antimicrobial susceptibility profiles were determined using disk diffusion method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and CLSI guidelines. Carbapenem-resistant K. pneumoniae isolates were identified. PCR method and sequencing were used for detection of blaKPC and blaGES carbapenemase genes. Of the 181 K. pneumoniae isolates, 35 (19.3%) were found to be resistant to imipenem and 150 (82.9%) were identified as MDR strains. Among carbapenems, the most resistant rate 39 (21.5%) was seen against ertapenem using disk diffusion method. Of K. pneumoniae isolates 21 (11.6%) and 42 (23.2%) carried blaKPC and blaGES genes, respectively and 19(10.5%) carried both genes simultaneously. CONCLUSION: The data of current study revealed that the frequency of resistance to carbapenems and production of carbapenemase enzymes especially GES type was high among clinical isolates of K pneumoniae in Kashan, Iran.201627527726
1427120.9869Prevalence and Characterization of Carbapenem-Resistant Enterobacteriaceae Isolated from Mulago National Referral Hospital, Uganda. INTRODUCTION: Carbapenemases have increasingly been reported in enterobacteriaceae worldwide. Most carbapenemases are plasmid encoded hence resistance can easily spread. Carbapenem-resistant enterobacteriaceae are reported to cause mortality in up to 50% of patients who acquire bloodstream infections. We set out to determine the burden of carbapenem resistance as well as establish genes encoding for carbapenemases in enterobacteriaceae clinical isolates obtained from Mulago National Referral Hospital, Uganda. METHODS: This was a cross-sectional study with a total of 196 clinical isolates previously collected from pus swabs, urine, blood, sputum, tracheal aspirates, cervical swabs, endomentrial aspirates, rectal swabs, Vaginal swabs, ear swabs, products of conception, wound biopsy and amniotic fluid. All isolates were subjected to phenotypic carbapenemase screening using Boronic acid-based inhibition, Modified Hodge and EDTA double combined disk test. In addition, all the isolates were subjected to PCR assay to confirm presence of carbapenemase encoding genes. RESULTS: The study found carbapenemase prevalence of 22.4% (44/196) in the isolates using phenotypic tests, with the genotypic prevalence slightly higher at 28.6% (56/196). Over all, the most prevalent gene was blaVIM (21,10.7%), followed by blaOXA-48 (19, 9.7%), blaIMP (12, 6.1%), blaKPC (10, 5.1%) and blaNDM-1 (5, 2.6%). Among 56 isolates positive for 67 carbapenemase encoding genes, Klebsiella pneumonia was the species with the highest number (52.2%). Most 32/67(47.7%) of these resistance genes were in bacteria isolated from pus swabs. CONCLUSION: There is a high prevalence of carbapenemases and carbapenem-resistance encoding genes among third generation cephalosporins resistant Enterobacteriaceae in Uganda, indicating a danger of limited treatment options in this setting in the near future.201526284519
1417130.9868Prevalence and Phenotypic and Molecular Characterization of Carbapenemase-Producing Gram-Negative Bacteria in Gabon. Data collection and monitoring of carbapenemase-producing (CP) Gram-negative bacteria (GNB) are often limited. This study determined CP-GNB prevalence in Gabon and the genetic origins of the resistance genes. From January 2016 to March 2018, 869 clinically significant GNB isolates from inpatients and outpatients, and 19 fecal samples (inpatients) were analyzed in the main hospitals of Gabon. Fecal samples were screened using ChromID® CARBA SMART selective chromogenic medium biplates. Species were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Antibiotic susceptibility was tested using the disk diffusion method on Müller-Hinton agar, and resistance genes were assessed by multiplex polymerase chain reaction and sequencing. Overall, 1.61% of clinical isolates (14 of 869) and 5.26% of fecal samples (1 of 19) were CP-GNB. The CP-GNB rate was higher among inpatients (2.98%) than outpatients (0.33%), in intensive care units (28.57%, 4 of 14), and in urine samples (35.71%, 5 of 14). The most common CP-GNB were Klebsiella pneumoniae (53.33%) and Acinetobacter baumannii (26.67%). blaOXA-48 was the predominant carbapenemase-encoding gene (40%), followed by blaNDM-5 (33.33%). The A. baumannii multilocus sequence types ST2 and ST78, Enterobacter cloacae ST78, Escherichia coli ST2, and K. pneumonia ST48 and ST147 were found. These data indicate that CP bacteria are present in clinical and carriage samples. Preventive measures are needed to avoid the spread of resistance genes.202336535247
1418140.9868Nosocomial infections and antimicrobial susceptibility patterns among patients admitted to intensive care unit of Imam Khomeini hospital in Ilam, Iran. INTRODUCTION: Nosocomial infections (NIs) are a major challenge worldwide. Identification of antibiotic resistance pattern extended spectrum beta-lactamases (ESBLs) and carbapenem-resistant Enterobacteriaceae (CRE) were the objectives of this study. METHODS: In this cross-sectional study, the antimicrobial susceptibility pattern of bacterial isolates collected from patients with NIs in ICU was determined. Overall, 42 Escherichia coli and Klebsiella pneumoniae isolates from different infection sites were used to determine phenotypic tests of ESBLs, Metallo-β-lactamases (MBLs) and CRE. Detection of ESBLs, MBLs and CRE genes were performed by the polymerase chain reaction (PCR) method. RESULTS: From 71 patients with NIs, 103 different bacterial strains were isolated. The most frequently isolated bacteria were E. coli (n = 29; 28.16%), Acinetobacter baumannii (n = 15; 14.56%), and K. pneumoniae (n = 13; 12.26%). Also, the rate of multidrug-resistant (MDR) isolates was 58.25% (60/103). Based on phenotypic confirmation tests, 32 (76.19%) isolates of E. coli and K. pneumoniae produced ESBLs, and 6 (14.28%) isolates were identified as CRE producers. PCR showed the high prevalence of the bla(CTX-M) (n = 29; 90.62%) in ESBL genes. In addition, bla(NDM) was detected in 4 (66.66%), bla(OXA-23) in 3 (50%), and bla(OXA-48) gene in 1 (16.66%) isolates. The bla(VIM), bla(KPC), and bla(IMP) genes were not detected in any of the isolates. CONCLUSION: The Gram-negative bacteria E. coli, A. baumannii, and K. pneumoniae with high resistance levels were the most common bacteria causing NIs in the ICU. This study for the first time identified bla(OXA-11), bla(OXA-23), and bla(NDM-1) genes in E. coli and K. pneumoniae in Ilam city of Iran.202337155016
1402150.9868Detection of β-lactam resistance genes in Gram-negative bacteria from positive blood cultures using a microchip-based molecular assay. BACKGROUND: Accurate detection of β-lactam resistance genes in bloodstream infections is critical for guiding antimicrobial therapy. This study evaluates the Alifax Gram-negative resistance (GNR) microchip assay for detecting β-lactam resistance genes directly from positive blood cultures (PBCs) for Gram-negative (GN) bacteria, including Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter baumannii. METHODS: Simulated (n=146) and clinical (n=106) GN-PBC samples were tested for bla (KPC), bla (VIM), bla (NDM), bla (IMP), bla (OXA-23)-like, bla (OXA-48)-like, bla (SHV)-ESBL, bla (CTX-M-1/9) group, and bla (CMY-2)-like genes using the GNR microchip assay. Whole-genome sequencing (WGS) served as the reference assay for simulated samples and, selectively, for clinical samples. The bioMérieux BioFire Blood Culture Identification 2 (BCID2) panel assay was used as a comparator for clinical samples. RESULTS: The GNR microchip assay correctly identified 203 (99.5%) of 204 β-lactam resistance genes in simulated samples. One sample tested false negative for a bla (SHV)-ESBL gene but true positive for a bla (KPC) gene. In clinical samples, GNR results were concordant with BCID2 for 113 (100%) of 113 genes included in both assays. Additionally, the GNR assay detected bla (CMY-2) -like (n=6), bla (OXA-23)-like (n=5), and bla (SHV)-ESBL (n=2), which are not targeted by BCID2, all confirmed by WGS. In two β-lactam-resistant P. aeruginosa samples but negative by the GNR assay, WGS confirmed the absence of acquired β-lactam resistance genes, suggesting alternative resistance mechanisms. CONCLUSION: The GNR microchip assay demonstrated high concordance and broader β-lactam resistance gene coverage compared to BCID2, supporting its potential role in routine diagnostics. Further validation in larger, prospective studies is warranted.202540529307
1412160.9868A highly multiplexed melt-curve assay for detecting the most prevalent carbapenemase, ESBL, and AmpC genes. Resistance to third-generation cephalosporins and carbapenems in Gram-negative bacteria is chiefly mediated by beta-lactamases including extended-spectrum beta-lactamase (ESBL), AmpC, and carbapenemase enzymes. Routine phenotypic detection methods do not provide timely results, and there is a lack of comprehensive molecular panels covering all important markers. An ESBL/carbapenemase high-resolution melt analysis (HRM) assay (SHV, TEM, CTX-M ESBL families, and NDM, IMP, KPC, VIM and OXA-48-like carbapenemases) and an AmpC HRM assay (16S rDNA control, FOX, MOX, ACC, EBC, CIT, and DHA) were designed and evaluated on 111 Gram-negative isolates with mixed resistance patterns. The sensitivity for carbapenemase, ESBL, and AmpC genes was 96.7% (95% confidence interval [CI]: 82.8-99.9%), 93.6% (95% CI: 85.7-97.9%), and 93.8% (95% CI: 82.8-98.7%), respectively, with a specificity of 100% (95% CI: 95.6-100%), 93.9% (95% CI: 79.8-99.3%), and 93.7% (95% CI: 84.5-98.2%). The HRM assays enable the simultaneous detection of the 14 most important ESBL, carbapenemase, and AmpC genes and could be used as a molecular surveillance tool or to hasten detection of antimicrobial resistance for treatment management.202032521424
1431170.9867The using of the polymerase chain reaction for the detection of resistance genes in gram-negative bacteria in routine practice in a pediatric hospital. Objective - assessment of RT-PCR for the detection of carbapenem-resistance genes in gram-negative bacteria. A total, 499 strains of gram-negative microorganisms isolated in two pediatric hospitals in 2019-2020 were studied. Species identification was performed using MALDI-ToF mass-spectrometry (Bruker Daltonics, Germany). Meropenem and imipenem minimal inhibitory concentration (MIC) was determined by E-test method (BioMerieux, France). The presence of acquired carbapenemase genes of IMP, NDM, VIM, KPC, OXA-48, OXA-23, OXA-40, OXA-58-groups was determined by RT-PCR. Klebsiella pneumoniae (34%), Escherichia coli (4%), Serratia marcescens (6%) and other members of Enterobacterales (6%), also gram-negative non-glucose-fermenting bacteria Acinetobacter baumannii (14%), Pseudomonas aeruginosa (36%) were found among selected strains. Carbapenemase production was found in 385 isolates (77%). The main mechanism determining carbapenem resistance in P. aeruginosa was the production of blaVIM (100%). A. baumanii strains harbored OXA-23 (55%) and OXA-40 (45%) carbapenemases. The major determinant of carbapenem resistance in K. pneumoniae isolates was OXA-48 carbapenemase, detected in 63% strains, 13% of the strains possessed blaNDM-group, 16% isolates had a combination of blaNDM-group and blaOXA-48-like. Carbapenemase of KPC-group was found in 8% K. pneumoniae strains. OXA-48 carbapenemase prevailed (95%) among S. marcescens strains. Most of E. coli isolates harbored metallo-beta-lactamase NDM (89%). Other members of Enterobacterales most often had OXA-48 carbapenemase (57%), 39% of the isolates carried blaNDM-group. In one strain, a combination of blaNDM-group and blaOXA-48-like was discovered. RT-PCR is a fast and reliable method for the detection of acquired carbapenemases and can be recommended for routine use in bacteriological laboratories.202235320635
1462180.9867Phenotypic synergy testing of ceftazidime-avibactam with aztreonam in a university hospital having high number of metallobetalactamase producing bacteria. BACKGROUND: Ceftazidime-avibactam combination with aztreonam and role of rapid synergy reporting has not been widely evaluated. Also the synergy correlation with various betalactamases has not been widely studied. METHODS: We studied phenotypic synergy testings and molecular detection of betalactamases in our university hospital where we have large number of mellatobetalactmase producing bacteria. We tested two phenotypic synergy methods for ceftazidime-avibactam with aztreonam (Disc-E strip method, E strip-Agar method) for rapid reporting to clinicians (153 isolates). The treatment (colistin, ceftazidime-avibactam, ceftazidime-avibactam with aztreonam) was guided as indicated in the synergy testings. The resistance genes in bacteria were identified by polymerase chain reaction (PCR) and correlated with synergy results. RESULTS: The highest synergy was seen in Klebsiella pneumoniae by Disc-E strip and E strip-Agar method (86% and 84% respectively). About 70% of Pseudomonas aeruginosa and 29% of Escherichia coli showed synergy. Molecular methods revealed multiple resistance gene combinations and bla(NDM) (96%) was predominant gene in isolates showing synergy. Among isolates that were sensitive to ceftazidime-avibactam, the predominant genes were bla(OXA-48) and bla(IMP.) Rapid laboratory reporting led to proper utilization of antibiotic combinations. CONCLUSIONS: Ceftazidime-avibactam and aztreonam rapid synergy testing will be highly beneficial in treatment of infections by metallobetalactamase producing resistant bacteria, especially K. pneumoniae and P. aeruginosa.202032628575
1433190.9867Carbapenem resistance in gram-negative pathogens in an Iranian hospital: high prevalence of OXA-type carbapenemase genes. BACKGROUND: The widespread dissemination of carbapenem- resistant gram-negative bacteria poses a significant threat to global public health. PURPOSE: This study aimed to investigate the prevalence of carbapenem resistance in gram-negative bacteria isolated from patients at the Children's Medical Center Hospital, Tehran, Iran, to understand the molecular mechanisms underlying this resistance. METHODS: During the period spanning from June 2019 to June 2020, 777 gram-negative bacterial strains were isolated. Antibiotic susceptibility testing was performed according to Clinical and Laboratory Standards Institute. Polymerase chain reaction was used to detect carbapenem resistance genes including bla OXA23, bla OXA24, bla OXA48, bla OXA51, bla OXA58, bla OXA143, bla KPC, bla IMP, bla VIM, and bla NDM. RESULTS: Among the total bacterial isolates, 141 (18.1%) exhibited carbapenem resistance. Escherichia coli was the most prevalent (57.4%), followed by Klebsiella pneumoniae (11.3%), and Acinetobacter baumannii (10.6%). Other notable contributors included Enterobacter spp. (5.7%), Salmonella spp. (3.5%), and Stenotrophomonas maltophilia (2.8%). Citrobacter spp., Proteus mirabilis, and Pseudomonas aeruginosa contributed to the distributions of 2, 1, and 3 isolates, respectively. Notably, bla OXA48 showed the highest prevalence (33%), followed by bla OXA143 and bla OXA5 8 (27% and 24%, respectively). In addition, bla OXA24 was present in 11% of the total isolates, bla OXA23 in 10%, and bla NDM in 10%, whereas bla KPC, bla VIM, and bla IMP were not detected. CONCLUSION: Our study highlights the prevalence of carbapenemase- producing gram-negative isolates among pediatric patients. Notable resistance patterns, especially in K. pneumoniae and E. coli, underline the urgent need for proactive interventions, including appropriate antibiotic prescription practices and strengthening of antibiotic stewardship programs.202539483044