scholarly journals The Investigation of OXA-48 and Sub-Derivatives in Klebsiella pneumoniae Strains and Phenotypic Reflection

ANKEM Dergisi ◽  
2021 ◽  
Author(s):  
Arzu Uyanık Parlak ◽  
Hüseyin Güdücüoğlu ◽  
Mehmet Parlak ◽  
Yasemin Bayram ◽  
Barış Otlu

The number of infections caused by carbapenem-resistant Gram negative bacteria is increasing among nosocomial infections. These bacteria are a serious threat to health because they are usually resistant to other antibiotics. This study was aimed to determine the carbapenemase resistance of OXA-48 and its subderivatives in Klebsiella pneumoniae isolates isolated from various clinical samples by phenotypic and genotypic methods and to investigate the presence of OXA-48 gene region genotypically in isolates without resistance. A total of 127 K.pneumoniae strains isolated from patients treated in various clinics and intensive care units were included in this study from March 2015 to March 2016. The isolates were identified and susceptibilities were tested using BD Phoenix automated system and also with Kirby-Bauer disk diffusion method. The presence of resistance was examined phenotypically with the disk of temosillin, which is considered to indicate the presence of OXA-48 type enzymes. The presence of OXA-48 type enzyme was investigated by “in-house” polymerase chain reaction (PCR) in all isolates and the presence of OXA-48 variant was investigated by DNA sequencing analysis on positive isolates. Carbapenem resistance rate was 35 % and ESBL positivity was determined as 46 %. The sensitivity of temocillin disk method in the identification of OXA-48 gene presence in K. pneumoniae strains was found to be 88 %, and specificity 89 %. Ertapenem was the best carbapenem with sensitivity and specificity balance to detect carbapenem resistance caused by OXA-48. The presence of blaOXA-48 gene region was 80 % in K. pneumoniae isolates detected as resistant to carbapenems by an automated system. All sequences obtained by DNA sequence analysis of 42 OXA-48 positive isolates were OXA-48 and there was no variant OXA-48 gene among the sequences. It was observed that the phenotypic reflection of resistance did not occur immediately in three isolates genotypically having OXA-48 gene region. The presence of blaOXA-48 gene region in carbapenems-resistant K.pneumoniae isolates is common. In addition, in some isolates having OXA-48 gene region, should be kept in mind in patients who do not recover despite treatment, due to phenotypic reflection of resistance does not occur immediately

2020 ◽  
pp. 517-527
Author(s):  
Sarab Murad Kadum

A total of 157 clinical samples were collected from different clinical specimens (urine, sputum, blood, swabs, and cannula) from several hospitals in Iraq. Among the samples, 51 isolates (32.48%) of Klebsiella pneumoniae were identified according to morphologicaland cultural characteristics as well as the Enterosystem 18R test. Higher numbers of K. pneumoniae isolates were observed in urine samples (26, 52%) than the other samples, and in females (70.6%) than males (29.4%) (female: male ratio of about 2.4:1). Antibiotic susceptibility of K. pneumoniae against 12 commonly used antibiotics was determined through the disc-diffusion method. The results revealed a higher resistance rate in 51 isolates (100%) against Cephalexin, followed by Ceftazidime (50, 98%), while the lowest resistance rate (24, 47%) was against each of Imipenem and Meropenem. Also, the investigation of the minimum inhibitory concentration (MIC) of Colistin using E-test (strips) demonstrated that 33 isolates were resistance, as compared to 31 using the disk diffusion assay. DNA was extracted from K. pneumoniae isolates and molecularly tested using polymerase chain technique (PCR) with a specific primer and 108 bp product to detect the rpoB gene that represents this bacteria . Also, all of the 51 isolates of K. pneumoniae identified by the rpoB gene were detected for the expression of the Colistin drug resistance gene mgr-B , which was amplified (347 bp) using a specific primer. Colistin resistance gene mgr-B was amplified and sequenced from the twenty isolates. Only 6 isolates appeared with a single nucleotide substitution; G instead A, A instead G, C instead G and G instead C. Also, this study tested biofilm formation from K. pneumoniae isolates , using the microtiter plate method, in association with Colistin and Carbapenem resistant. The Colistin and Carbapenem resistance pattern was compared to the ability of biofilm-formation as weak formation versus strong and also, Multi-drug resistant isolates were more common among weak versus strong biofilm formers.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Kiana Karimi ◽  
Omid Zarei ◽  
Parinaz Sedighi ◽  
Mohammad Taheri ◽  
Amin Doosti-Irani ◽  
...  

Aim. Klebsiella pneumoniae (K. pneumoniae) is an encapsulated Gram-negative bacterium that can lead to 14–20% of nosocomial infections. The ability of biofilm formation in this bacterium decreases the host immune response and antibiotic efficacy. This may impose a huge impact on patients and healthcare settings. This study aimed to evaluate the antibiotic resistance pattern and biofilm formation in K. pneumoniae strains isolated from two major Hamadan hospitals, west of Iran. Methods. A total of 83 K. pneumoniae strains were isolated from clinical samples of patients in different wards of Hamadan hospitals from September 2018 to March 2019. Determination of antimicrobial susceptibility was performed using the disk diffusion method. Biofilm formation was evaluated by the crystal violet method. Data were analyzed by the SPSS software and chi-square test. Results. The results showed that clinical samples included 18 urinary tract samples (22%), 6 wound samples (7%), 6 blood samples (7%), 17 tracheal tube aspiration samples (20%), 32 throat cultures (38%), 2 sputum samples (2.5%), and 2 abscess drain cultures (2.5%). High-level resistance to cefotaxime was detected in 92%, and all of isolates were susceptible to colistin. Biofilm formation was seen in 62 (75%) isolates. Strong biofilm formation was observed in 17 (20%) strains. A significant correlation was seen between biofilm formation and antibiotic resistance ( P value <0.05). Conclusion. Our findings emphasize the need for proper diagnosis, control, and treatment of infections caused by K. pneumoniae especially in respiratory tract infections due to the strong biofilm formation and high antibiotic resistance in these strains.


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.


2007 ◽  
Vol 28 (8) ◽  
pp. 941-944 ◽  
Author(s):  
Thean Yen Tan ◽  
Karen Poh ◽  
Siew Yong Ng

Objective.To investigate the molecular epidemiology of carbapenem-resistantAcinetobacter baumannii-calcoaceticuscomplex isolates in a tertiary care hospital where the prevalence of carbapenem resistance among these organisms is high.Design.The study was a prospective, observational study performed during an 8-month period (May 1 through December 31, 2004).A. baumanniiisolates recovered from all clinical samples during the study period were included in the study. Antibiotic susceptibility testing was performed using the disk diffusion method, and all carbapenem-resistant strains were typed by a polymerase chain reaction-based typing method.Setting.An 800-bed hospital in Singapore.Results.More than half of recovered isolates were clonally unrelated, with the remaining isolates grouped into 4 genotypes.Conclusions.The results of the study suggest that the high prevalence of carbapenem resistance amongAcinetobacterorganisms in this institution is not caused by the spread of a predominant clone and that other factors may need to be investigated.


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.


Author(s):  
Mariona Xercavins ◽  
Elena Jiménez ◽  
Emma Padilla ◽  
Montserrat Riera ◽  
Núria Freixas ◽  
...  

Abstract Background Klebsiella pneumoniae has been responsible for a large number of clonal hospital outbreaks. However, some epidemiological changes have been observed since the emergence of CTX-M enzymes in K. pneumoniae. Aim To analyse the transmission dynamics of Extended Spectrum β-Lactamase-producing Klebsiella pneumoniae (ESBL-Kp) in an acute care hospital. Methods In 2015 a prospective cohort study was conducted. All new consecutive adult patients with ESBL-Kp isolates in all clinical samples were included. Patients with a previous known infection/colonization by ESBL-Kp and patients in high risk areas (e.g., intensive care units) were excluded. Cross-transmission was defined as the carriage of a clonally-related ESBL-Kp between newly diagnosed patients who shared the same ward for ≥48 h with another case, within a maximum time window of 4 weeks. ESBL-production was confirmed using the double-disk diffusion method and PCR. Clonal relationships were investigated by rep-PCR and multilocus sequence typing (MLST). Results Sixty ESBL-Kp isolates from 60 patients were included and analysed. Infections and colonizations were classified as hospital-acquired (52%), healthcare-related (40%) or community-acquired (8%). High genetic diversity was detected. When epidemiological clinical data were combined with the rep-PCR, the patterns identified did not show any cases of cross-transmission. ESBL-Kp were detected in 12.5% of environmental samples. No clonal relationship could be established between environmental reservoirs and patients. The genetic mechanism detected in all strains was associated with blaCTX-M genes, and 97% were CTX-M-15. Conclusions The dynamics of ESBL-K. pneumoniae isolated in our setting could not be explained by clonal transmission from an index patient. A polyclonal spread of ESBL-Kp was identified.


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.


Author(s):  
Saeed Khoshnood ◽  
Mohsen Heidary ◽  
Ali Hashemi ◽  
Fatemeh Shahi ◽  
Morteza Saki ◽  
...  

Background: Increasing prevalence of multiple antibiotic resistance in Klebsiella pneumoniae strains confines the therapeutic options used to treat bacterial infections. Objective: We aimed in this study to investigate the role of AcrAB, qepA efflux pump, and AAC(6′)-Ib-cr enzyme in ciprofloxacin resistance and to detect the RAPD-PCR fingerprint of K. pneumoniae isolates. Methods: In total, 117 K. pneumoniae isolates were collected from hospitalized patients in three hospitals in Tehran, Iran from August 2013 to March 2014. Antimicrobial susceptibility tests were performed by the disk diffusion method. Molecular identification and expression level of encoding quinolone resistance genes, acrA, acrB, qepA, and aac(6')-Ib-cr, was per-formed by PCR and real-time PCR assays, respectively. All the K. pneumoniae isolates containing these genes was used simultaneously for RAPD-PCR typing. Results: Colistin and carbapenems were the most efficient antibiotics against the clinical isolates of K. pneumoniae. PCR assay demonstrated that among the 117 isolates, 110 (94%) and 102 (87%) were positive for acrA and acrB gene, and for qepA and aac(6′)-Ib-cr genes, 5 (4%) and 100 (85%) isolates were detected, respectively. Determination of AcrAB pump expression in 21% of strains demonstrated an increased expression, and the mean increase expression for acrB genes was 0.5-81. The results of RAPD-PCR reflected that in 95% CI, all isolates belong to a clone. Conclusion: A high prevalence of genes encoding quinolone resistance in K. pneumoniae was detected in clinical samples. Therefore, control of infection and prevention of drug-resistant bacteria spread need careful management of medication and identification of resistant isolates.


2019 ◽  
Vol 13 (S11) ◽  
Author(s):  
Hera Nirwati ◽  
Kian Sinanjung ◽  
Fahrina Fahrunissa ◽  
Fernando Wijaya ◽  
Sarastia Napitupulu ◽  
...  

Abstract Background Klebsiella pneumoniae (K. pneumoniae) is a common cause of health-care associated infections (HAIs) and has high levels of antibiotic resistance. These bacteria are well-known for their ability to produce biofilm. The purpose of this study was to identify the antibiotic resistance pattern and biofilm-producing capacity of K. pneumoniae isolated from clinical samples in a tertiary care hospital in Klaten, Indonesia. Methods K. pneumoniae was isolated from inpatients in Soeradji Tirtonegoro Hospital Klaten from June 2017 to May 2018. Identification of K. pneumoniae isolate was done by analyzing colony morphology, microscopic examination, and by performing biochemical testing. Testing of antibiotics susceptibility and biofilm-producing capacity used the Kirby-Bauer disk diffusion method and adherence quantitative assays, respectively. Results A total of 167 (17.36%) K. pneumoniae isolates were isolated from 962 total clinical bacterial isolates during the study. Most of them were collected from patients aged more than 60 years old and were mainly obtained from respiratory specimens (51.50%). Most of K. pneumoniae isolates were extensively resistant to antibiotics. A more favorable profile was found only towards meropenem, amikacin, and piperacillin-tazobactam, showing 1.20%; 4.79% and 10.53% of resistance, respectively. The overall proportion of multidrug-resistant K. pneumoniae isolates was 54.49%. In addition, 148 (85.63%) isolates were biofilm producers, with 45 (26.95%) isolates as strong, 48 (28.74%) isolates as moderate, and 50 (29.94%) isolates as weak biofilm producers. Conclusion Most of the K. pneumoniae isolates demonstrated resistance to a wide range of antibiotics and are biofilm producers.


Sign in / Sign up

Export Citation Format

Share Document