scholarly journals β-lactamase genes in carbapenem resistance Acinetobacter baumannii isolates from a Turkish university hospital

2019 ◽  
Vol 13 (01) ◽  
pp. 50-55
Author(s):  
Umut Safiye Say Coskun ◽  
Emel Caliskan ◽  
Asegul Copur Cicek ◽  
Halbay Turumtay ◽  
Cemal Sandalli

Introduction: The spread of Acinetobacter baumannii, resistant to most of the available antimicrobial agents, is a serious health problem. The high rate of carbapenem resistance among Acinetobacter baumannii isolates is considered as a threat to public health. In this study, we aimed to determine the antibiotic resistance and related genes in carbapenem-resistant Acinetobacter baumannii isolates. Methodology: Ninety six isolates of A. baumannii were included. Antimicrobial susceptibility was performed by Phoenix Automated System and disk diffusion method. Carbapenem resistane was characterized by scrneeing of resistance genes such as blaTEM, blaSHV, blaCTX-M1-2, blaPER, blaVEB, blaKPC, blaGES, blaNDM, blaVIM, blaIMP and blaOXA23-24-51-58 using multiplex polymerase chain reaction. Results: Resistance for the levofloxacin, gentamicin, amikacin, and tigecycline were determined as 96.9%, 93.7%, 72.9% and 45.8% respectively. Colistin was the only susceptible antibiotic against all clinical isolates. All isolates were defined as multidrug resistance and of these, 31.2% were extensively drug-resistant (sensitive only to colistin). BlaOXA-51­  and blaOXA-23 genes were detected in 100% strains while blaTEM was found in only 2% strains. There was no amplification for the blaSHV, blaCTX-M1-2, blaPER, blaVEB, blaKPC, blaGES blaNDM, blaVIM, blaIMP and blaOXA24-58 genes. Conclusions: The high frequency of blaOXA-23 and low frequency of blaTEM gene was observed that indicate prevalence of a variety of A. baumannii strains. The rates of resistance genes vary from region to region. Studies are required for the prevention and control of A. baumannii infection and to formulate the strategies of antibiotic usage.

2020 ◽  
Vol 13 (2) ◽  
pp. 1-8
Author(s):  
Aleruchi Chuku ◽  
Godwin Attah Obande ◽  
Sani Bashir Eya

Background and objective: Listeria sp. is a ubiquitous and frequently isolated foodborne pathogen. The prevalence of Listeria sp in raw beef and chevon sold in Lafia Nigeria, as well as their antibiotic susceptibility profile was evaluated. Methods: A total 104 samples comprising of 52 raw beef and 52 chevon were obtained from street vendors (hawkers), Shinge abattoir, Lafia old market and Lafia Modern Market. Isolation of Listeria sp. was performed on Listeria Selective Agar, following enrichment in supplemented Listeria Selective Broth. Identification of Listeria sp. was carried out by cultural and biochemical methods. Antimicrobial susceptibility of isolated L. monocytogenes was performed by standard disk diffusion method. Chi-square test was used to determine association between contamination levels at p=0.05. Results: Seven types of Listeria sp. were isolated. L. monocytogenes and L. ivanovii were the most frequently isolated contaminants in all meat types and from all sample sources. L. monocytogenes was isolated with a frequency of 64.4% (67/104) in the meat samples. Beef samples had the highest listerial contamination with a frequency of 58.2% (78/134) compared to chevon which had a listerial frequency of 41.8% (56/134). Resistance of L. monocytogenes to streptomycin and sparfloxacin was 58.2% and 55.2% respectively. Resistance to ampicillin (34.3%) and gentamicin (20.9%) was also observed. Resistances to multiple antimicrobials were detected in 11 L. monocytogenes isolates. Conclusion: The study demonstrated that the raw meat sold in Lafia was contaminated with several Listeria sp. L. monocytogenes showed high rate of resistance to several antimicrobial agents used for the treatment of listerial infection. Appropriate regulation and monitoring of livestock rearing and meat retailing practices are advocated to safeguard the health of consumers. Ibrahim Med. Coll. J. 2019; 13(2): 1-8


Author(s):  
Ranjit Sah ◽  
Shusila Khadka ◽  
Gentle Sunder Shrestha ◽  
Subhash Acharya ◽  
Diptesh Aryal ◽  
...  

Abstracts Background Resistance to antimicrobial agents of pathogenic bacteria has become a major problem in routine medical practices. Carbapenem resistance has long been increasing. The production of carbapenem- hydrolysing β-lactamases (carbapenamases), which include NDM, KPC, OXA-48, IMP-1 and VIM is the most common mechanism. Case presentation A 56 years old male presented with fever and mental changes with progressively decreasing sensorium for the last 3 days. He was admitted to Intensive care unit (ICU) with a diagnosis of meningoencephalitis. On day seven, he developed ventilator associated pneumonia due Klebsiella pnemoniae and Acinetobacter baumannii. He was on meropenem, but the isolates were susceptible to colistin, tigecyclin and amikacin solely. Hence, amikacin was started with addition of intravenous and nebulized colistin. Subsequently, vital signs improved with resolution of fever. However, on day 18, he developed fever once again with a drop in blood pressure. Inotropic support was maintained, and echinocandins and tigecycline were added to the regimen. Repeat blood and urine culture grew Providencia species, which were resistant to most of the drugs on phenotypic Kirby-Bauer disk diffusion method and are intrinsically resistant to colistin and tigecycline. Phenotypic detection of ESBL (combined disk method), MBL, KPCs, AmpC and co-producer were tested according to updated CLSI guideline and all were negative. But the Modified Hodges test was found to be positive. Consequenty, OXA-48 drug resistance pattern was brought into action by blank disc method according to A Tsakris et al., which revealed indentation of growth toward both EDTA and EDTA/PBA disk indicating production of OXA-48 carbapenamase. To confirm the resistance pattern we processed the isolated colonies for Xpert Carba-R (Cepheid) assay, which detected blaOXA-48 gene and confirmed the OXA-48 drug resistance pattern. Hence, the infecting organism was not susceptible to any of the antibiotics. The patient was kept under isolation and on 31th day of admission, he died of septic shock. Conclusions Carbapenamase production along with intrinsic colistin resistance in infecting bacterial pathogens can cause fatal outcomes in the resource limited countries like Nepal where new antibiotic combinations ceftazidime+ Avibactam, or aztreonam +avibactam are not available. Drug resistance patterns including OXA 48 producer should be characterized in all cases by standard phenotypic methods or by Xpert Carba-R assay and larger studies are required to know the exact burden of OXA 48 producer in Nepal.


2012 ◽  
Vol 6 (06) ◽  
pp. 489-494 ◽  
Author(s):  
Alaa Hani Al-Charrakh

Introduction: The presence of microorganisms in pharmaceuticals is undesirable because they may cause spoilage of the product and may present an infection hazard to the consumers or patients.  Methodology: A total of 102 samples of oral and topical non-sterile pharmaceutical products were collected at random from different drug houses and pharmacies in Iraq, to investigate the microbial contamination of these products. Bacterial isolates recovered from these medicaments were subjected to susceptibility testing against various antibiotics by disk diffusion method according to Clinical and Laboratory Standards (CLSI) guidelines. Results: The results revealed that the occurrence of Gram-positive bacteria was in oral and topical medicaments while Gram-negative bacteria were only detected in topical medicaments. More than 58% of Bacillus isolates were resistant to lincomycin and Bacillus mycoides isolates were resistant to beta-lactam antibiotics and trimethoprim-sulfamethoxazole. Staphylococcus spp. showed a relatively high resistance to ampicillin, amoxicillin, penicillin, tetracycline, and trimethoprim-sulfamethoxazole. S. epidermidis had the highest number of multi-resistant isolates. Furthermore, 87.5% of isolated Gram-negative rods showed high resistance to beta-lactam antibiotics and 75% of them were highly resistant to erythromycin. One isolate of Pseudomonas aeruginosa was the most resistant among all Gram-negative rod isolates. Conclusion: The high rate of resistance to antimicrobial agents of bacterial isolates recovered from oral and topical medicaments in this study may indicate a widespread antibiotic resistance among bacteria isolated from different sources, including those of anthropological and environmental origin. 


Author(s):  
Nabil Karah ◽  
Fizza Khalid ◽  
Sun Nyunt Wai ◽  
Bernt Eric Uhlin ◽  
Irfan Ahmad

Abstract Background Acinetobacter baumannii is a Gram-negative opportunistic pathogen with a notorious reputation of being resistant to antimicrobial agents. The capability of A. baumannii to persist and disseminate between healthcare settings has raised a major concern worldwide. Methods Our study investigated the antibiotic resistance features and molecular epidemiology of 52 clinical isolates of A. baumannii collected in Pakistan between 2013 and 2015. Antimicrobial susceptibility patterns were determined by the agar disc diffusion method. Comparative sequence analyses of the ampC and blaOXA-51-like alleles were used to assign the isolates into clusters. The whole genomes of 25 representative isolates were sequenced using the MiSeq Desktop Sequencer. Free online applications were used to determine the phylogeny of genomic sequences, retrieve the multilocus sequence types (ST), and detect acquired antimicrobial resistance genes. Results Overall, the isolates were grouped into 7 clusters and 3 sporadic isolates. The largest cluster, Ab-Pak-cluster-1 (blaOXA-66 and ISAba1-ampC-19) included 24 isolates, belonged to ST2 and International clone (IC) II, and was distributed between two geographical far-off cities, Lahore and Peshawar. Ab-Pak-clusters-2 (blaOXA-66, ISAba1-ampC-2), and -3 (blaOXA-66, ISAba1-ampC-20) and the individual isolate Ab-Pak-Lah-01 (ISAba1-blaOXA-66, ISAba1-ampC-2) were also assigned to ST2 and IC II. On the other hand, Ab-Pak-clusters-4 (blaOXA-69, ampC-1), -5 (blaOXA-69, ISAba1-ampC-78), and -6A (blaOXA-371, ISAba1-ampC-3) belonged to ST1, while Ab-Pak-cluster-6B (blaOXA-371, ISAba1-ampC-8) belonged to ST1106, with both ST1 and ST1106 being members of IC I. Five isolates belonged to Ab-Pak-cluster-7 (blaOXA-65, ampC-43). This cluster corresponded to ST158, showed a well-delineated position on the genomic phylogenetic tree, and was equipped with several antimicrobial resistance genes including blaOXA-23 and blaGES-11. Conclusions Our study detected the occurrence of 7 clusters of A. baumannii in Pakistan. Altogether, 6/7 of the clusters and 45/52 (86.5%) of the isolates belonged to IC I (n = 9) or II (n = 36), making Pakistan no exception to the global domination of these two clones. The onset of ST158 in Pakistan marked a geographical dispersal of this clone beyond the Middle East and brought up the need for a detailed characterization.


Author(s):  
Maria Chatzidimitriou ◽  
Panagiota Chatzivasileiou ◽  
Georgios Sakellariou ◽  
MariaAnna Kyriazidi ◽  
Asimoula Kavvada ◽  
...  

AbstractThe present study evaluated the carbapenem resistance mechanisms of Klebsiella pneumoniae strains isolated in two Greek tertiary teaching hospitals and their susceptibility to currently used and novel antimicrobial agents.Forty-seven carbapenem resistant K. pneumoniae strains were collected in G. Papanikolaou and Ippokrateio hospital of Thessaloniki between 2016 and 2018. Strain identification and antimicrobial susceptibility was conducted by Vitek 2 system (Biomérieux France). Susceptibility against new antimicrobial agents was examined by disk diffusion method. Polymerase chain reaction (PCR) was used to detect blaKPC, blaVIM, blaNDM and blaOXA-48 genes.The meropenem–EDTA and meropenem–boronic acid synergy test performed on the 24 K. pneumoniae strains demonstrated that 8 (33.3%) yielded positive for metallo-beta-lactamases (MBL) and 16 (66.6%) for K. pneumonia carbapenemases (KPC) production. Colistin demonstrated the highest in vitro activity (87.7%) among the 47 K. pneumoniae strains followed by gentamicin (76.5%) and tigecycline (51%). Among new antibiotics ceftazidime/avibactam showed the highest sensitivity (76.6%) in all strains followed by eravacycline (66.6%). The blaKPC gene was present in 30 strains (63.8%), the blaNDM in 11 (23.4%) and the blaVIM in 6 (12.8%). The blaOXA-48 gene was not detected.Well established antimicrobial agents such as colistin, gentamicin and tigecycline and novel antibiotics like ceftazidime/avibactam and eravacycline can be reliable options for the treatment of invasive infections caused by carbapenem-resistant K. pneumoniae.


2013 ◽  
Vol 6 (1) ◽  
pp. 12-17
Author(s):  
Valentina P. Popova ◽  
Mariya P. Sredkova ◽  
Hristina H. Hitkova ◽  
Kaloyan T. Ivanov ◽  
Vladimir G. Popov

Summary Multidrug-resistant (MDR) enterococci are a growing threat. The aim of this study was to determine the species distribution and prevalence of multidrug resistance among 100 enterococcal strains, isolated from patients treated in the University Hospital in Pleven, Bulgaria. Susceptibility to 11 antimicrobial agents was determined, using the disc diffusion method according to the performance standards of Clinical Laboratory Standards Institute (CLS1), 2012. All isolates were screened for high-level aminoglycoside resistance and resistance to vancomycin according to the recommendations of CLS1, 2012. For strains with reduced susceptibility to vancomycin, minimal inhibitory concentrations (MIC) of glycopeptides were determined by Etest (Liofilchem, Italy) and by Vitek 2 automated system. Our results demonstrated decreased susceptibility of enterococci to almost all intensively used anti-enterococcal drugs. Resistance to both penicillins (ampicillin and penicillin) among E.faecium strains was significantly higher (83-87%) than among E.faecalis isolates (4-27%). HLGR was detected in 70% of E.faecium and 38% of E.faecalis isolates. All HLGR strains were foundtobemultiple-drug resistant. Of particular note was the emergence of concomitant resistance to 6 antimicrobials in almost 50% of E.faecium isolates. Despite the wide dissemination of MDR E.faecium strains penicillins in our hospital, acquired resistance to vancomycin was not found.


Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1054
Author(s):  
Nalumon Thadtapong ◽  
Soraya Chaturongakul ◽  
Sunhapas Soodvilai ◽  
Padungsri Dubbs

Resistance to the last-line antibiotics against invasive Gram-negative bacterial infection is a rising concern in public health. Multidrug resistant (MDR) Acinetobacter baumannii Aci46 can resist colistin and carbapenems with a minimum inhibitory concentration of 512 µg/mL as determined by microdilution method and shows no zone of inhibition by disk diffusion method. These phenotypic characteristics prompted us to further investigate the genotypic characteristics of Aci46. Next generation sequencing was applied in this study to obtain whole genome data. We determined that Aci46 belongs to Pasture ST2 and is phylogenetically clustered with international clone (IC) II as the predominant strain in Thailand. Interestingly, Aci46 is identical to Oxford ST1962 that previously has never been isolated in Thailand. Two plasmids were identified (pAci46a and pAci46b), neither of which harbors any antibiotic resistance genes but pAci46a carries a conjugational system (type 4 secretion system or T4SS). Comparative genomics with other polymyxin and carbapenem-resistant A. baumannii strains (AC30 and R14) identified shared features such as CzcCBA, encoding a cobalt/zinc/cadmium efflux RND transporter, as well as a drug transporter with a possible role in colistin and/or carbapenem resistance in A. baumannii. Single nucleotide polymorphism (SNP) analyses against MDR ACICU strain showed three novel mutations i.e., Glu229Asp, Pro200Leu, and Ala138Thr, in the polymyxin resistance component, PmrB. Overall, this study focused on Aci46 whole genome data analysis, its correlation with antibiotic resistance phenotypes, and the presence of potential virulence associated factors.


Author(s):  
Hasan Cenk Mirza ◽  
Banu Sancak

Objective: Members of Enterobacterales can cause various diseases in humans. The objective of this study was to determine the genus/species distribution and antimicrobial susceptibilities of Enterobacterales isolated from blood cultures in Central Laboratory of Hacettepe University Hospital. Method: Enterobacterales isolated from blood between July-2014 and April-2018 were included in the study. MALDI-TOF MS was used for the identification of isolates. Antimicrobial susceptibilities were determined with automated system (VITEK 2 Compact for the isolates between 2014 and 2018; BD Phoenix for the isolates in 2018) and disk diffusion method. Results of antimicrobial susceptibility testing were interpreted according to EUCAST breakpoints. Results: In total, 1765 isolates belonging to the order Enterobacterales were isolated from blood cultures. The most common microorganisms were Escherichia coli (47.6%), Klebsiella (34.1%), Enterobacter (6%), Proteus (4.4%) and Serratia spp. (3.5%), respectively. The remaining isolates included Salmonella, Citrobacter, M. morganii, Pantoea, Raoultella and Providencia spp. The lowest resistance rates among E. coli, Klebsiella and Enterobacter spp. isolates were observed against meropenem and amikacin. However, 21.1% of Klebsiella isolates were resistant to meropenem. The most active antimicrobials against Proteus isolates were piperacillintazobactam and meropenem. Resistance was not observed against piperacillin-tazobactam and meropenem among Proteus isolates. The most active antimicrobial against Serratia isolates was trimethoprim/ sulfamethoxazole with a resistance rate of 0%. Resistance was not noted against ampicillin and trimethoprim/ sulfamethoxazole among Salmonella isolates, whereas 26.1% of isolates were resistant to ciprofloxacin. All Citrobacter isolates were susceptible to meropenem, amikacin and cefepime. Conclusion: Findings of our study may guide the selection of proper antimicrobials for the treatment of bacteremia caused by Enterobacterales. Furthermore, this study provides important epidemiological information regarding the distribution of members of Enterobacterales causing bacteremia.


2021 ◽  
Vol 8 (4) ◽  
pp. 247-253
Author(s):  
Ali Ozturk ◽  
Hadice Ozcinar ◽  
Bashar Mohammed Salih Ibrahim ◽  
Mehmet Bayraktar

Objective: This study aimed to determine the antibiotic resistance, inducible beta-lactamase (IBL), and Metallo beta-lactamase (MBL) rates in P. aeruginosa isolates. Material and Methods: In our study, 100 P. aeruginosa isolates obtained from various clinical samples were used. Antibiotic susceptibility was performed by using the Kirby-Bauer disk diffusion method. Carbapenem resistance to imipenem and meropenem was verified by the E test. The disk induction method was used to determine the IBL production while the Modified Hodge test, MBL E test, and combined imipenem/ EDTA disk were used to determine the production of MBL. Results: According to the results of antibiotic susceptibility tests, 58% of P. aeruginosa isolates were susceptible to all antipseudomonal drugs, while resistance rates to other drugs were as follows; ceftazidime 7%, cefoperazone sulbactam 8%, cefepime 13%, piperacillin 14%, piperacillin-tazobactam 12%, imipenem 9%, meropenem 11%, aztreonam 8%, amikacin 8%, gentamicin 13%, tobramycin 12%, netilmicin 19%, There was a 10% resistance to ciprofloxacin. 8% of the isolates were resistant to at least three drugs, of which two isolates were positive for MBL enzyme production. IBL production was detected in 86% of the isolates with the disk induction method. Conclusion: The results we obtained in our study are consistent with other researchers globally and in Turkey. It was concluded that there is a need for well-standardized phenotypic tests with defined evaluation criteria and further studies to verify these tests genotypically.


2021 ◽  
Author(s):  
SeyedSajjad Khoramrooz ◽  
Saba Eslami ◽  
Mohammad Motamedifar ◽  
Abdollah Bazargani ◽  
Kamiar Zomorodian

Abstract Background Acinetobacter baumannii is a global concern to cause the health-care-associated infections, due to multidrug resistance against available commercially antimicrobial agents. Regarding this, the present study was conducted to determine the antimicrobial susceptibility of A.baumannii isolates from clinical specimens in Shiraz, and explore the possible relationship of susceptibility patterns with the presence of integrons and related gene cassettes. Methods A.baumannii isolates were collected, and their susceptibility to various antibiotics was tested using Kirby-Bauer disk diffusion method. Also, molecular analyses were performed to detect the presence of OXA-51 like gene, class I, II and III integrons, and associated gene cassettes. Results Majority of isolates demonstrated resistance to imipenem(99.4%),piperacilin(98.2%),gentamycin (98.2%) meropenem (97.7%)ceftazidime(95.4%)amikacin(95.4%) and trimethoprim-sulfamethoxazole (90.8%). All strains showed multidrug-resistance to most of the tested antibiotics. The distribution analysis of integrons genes showed that 90.2%, 72.4% and 12.1% of isolates carried the intI 1, intI2 and intI3 genes, respectively. Moreover, two types of prevalent gene cassettes including aad and dfr were detected in Class 1 integron-carrying strains. Conclusions The current study showed the high prevalence of A.baumannii isolates harboring integrons in our investigated medical center, which may propel distribution of multidrug resistance event. The different types of gene cassette arrays in the present study spotlight the remarkable role of geographical issues in MDR isolates dissemination. This subject could attribute to choose appropriate therapeutic interventions in different areas. Obtained data highlighted the necessity for continuous surveillance to prevent distribution of multidrug resistance among A.baumannii strains in Iran.


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