scholarly journals Prevalence of β-lactamase-encoding genes and molecular typing of Acinetobacter baumannii isolates carrying carbapenemase OXA-24 in children

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Neda Yousefi Nojookambari ◽  
Mehrzad Sadredinamin ◽  
Razieh Dehbanipour ◽  
Zohreh Ghalavand ◽  
Gita Eslami ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Genetic Relatedness ◽  
Medical Center ◽  
Resistance Rate ◽  
Diffusion Method ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests ◽  
Encoding Genes

Abstract Background β-Lactam antibiotics have been broadly used for the treatment of Acinetobacter baumannii infections, resulting in development of β-lactam inactivating β-lactamases. Here, we described antibiotic resistance rate, prevalence of β-lactamase-encoding genes, and clonal relationships of A. baumannii strains isolated from children referred to Children’s Medical Center in Tehran, Iran, during 2019–2020. Methods A total of 60 non-replicate A. baumannii isolates were recovered from clinical specimens of pediatric patients. Antibiotic susceptibility testing was done by the disc diffusion method. Colistin susceptibility of isolates was performed by the broth microdilution method. β-lactamase-encoding genes were characterized by PCR. The presence of ISAba1 element upstream of the several oxacillinase genes was also checked. Genetic relatedness of isolates was determined by using random amplification of polymorphic DNA (RAPD) typing. Results The antimicrobial susceptibility tests showed that 83.3% of A. baumannii isolates were MDR, and 40% XDR. Both MDR and XDR A. baumannii isolates were susceptible to colistin. The frequency of blaOXA-51-like, blaOXA-23-like, blaTEM, blaOXA-24-like, blaPER, blaSHV, blaCTX-M, blaOXA-58-like, and blaIMP was 100, 93.33, 60, 36.67, 28.33, 8.33, 5, 3.33, and 1.67%, respectively. Coexistence of ISAba1/blaOXA-23-like and ISAba1/blaOXA-51-like was observed in 65% and 85% of isolates, respectively. RAPD analysis revealed 4 common types and 2 single types of A. baumannii isolates. Conclusions The multiple clones harboring blaOXA-23-like, ISAba1-blaOXA-51-like, and ISAba1-blaOXA-23-like were responsible for the spread of A. baumannii isolates in our clinical wards. Dissemination of the well-established clones is worrisome and would become therapeutic challenges due to the possible transferring genetic elements associated with resistance.

scholarly journals Molecular Detection of Carbapenemase-Encoding Genes in Multidrug-Resistant Acinetobacter baumannii Clinical Isolates in South Africa

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yaw Adjei Anane ◽  
Teke Apalata ◽  
Sandeep Vasaikar ◽  
Grace Emily Okuthe ◽  
Sandile Songca
Keyword(s):  
South Africa ◽  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Clinical Samples ◽  
Eastern Cape ◽  
Healthcare Facilities ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
High Level ◽  
Encoding Genes

Introduction. Carbapenem-resistant Acinetobacter baumannii has been responsible for an increasing number of hospital-acquired infections globally. The study investigated the prevalence of carbapenemase-encoding genes in clinical multidrug-resistant A. baumannii strains. Materials and Methods. A total of 100 nonduplicate multidrug-resistant A. baumannii strains were cultured from clinical samples obtained from healthcare facilities in the O. R. Tambo district. The strains were confirmed by detecting the intrinsic blaOXA-51-like gene. Antimicrobial susceptibility testing was performed by VITEK® 2 and autoSCAN-4 systems. The MIC of imipenem and meropenem was rechecked by E-test. Colistin MIC was confirmed by the broth microdilution method. Real-time PCR was performed to investigate the presence of carbapenemase-encoding genes. Results. Most strains showed high resistance rates (>80%) to the antibiotics tested. Resistance to amikacin, tetracycline, and tigecycline were 50%, 64%, and 48%, respectively. All strains were fully susceptible to colistin. The blaOXA-51-like was detected in all strains whilst blaOXA-23-like, blaOXA-58-like, blaOXA-24-like, blaIMP-1, blaVIM, and blaNDM-1 were found in 70%, 8%, 5%, 4%, 3%, and 2% of strains, respectively. None of the tested strains harboured the genes blaSIM and blaAmpC. The coexistence of blaOXA-23-like, and blaIMP-1 or blaOXA-58-like was detected in 1% and 2% strains, respectively. A distinct feature of our findings was the coharbouring of the genes blaOXA-23-like, blaOXA-58-like, and blaIMP-1 in 2% strains, and this is the first report in the Eastern Cape Province, South Africa. The intI1 was carried in 80% of tested strains whilst ISAba1/blaOXA-51-like and ISAba1/blaOXA-23-like were detected in 15% and 40% of the strains, respectively. The detection of blaOXA-23-like, ISAba1/blaOXA-51-like, ISAba1/blaOXA-23-like, and blaOXA-23-like, blaOXA-58-like, and blaIMP-1 carbapenemases in strains had a significant effect on both imipenem and meropenem MICs. Conclusions. Results showed a high level of oxacillinases producing A. baumannii circulating in our study setting, highlighting the need for local molecular surveillance to inform appropriate management and prevention strategies.

The prevalence and antimicrobial resistance of Haemophilus influenzae in prepubertal girls with vulvovaginitis

2020 ◽  
Author(s):  
Mingming Zhou ◽  
Liying Sun ◽  
Xuejun Chen ◽  
Chao Fang ◽  
Jianping Li ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Haemophilus Influenzae ◽  
Resistance Rate ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Ampicillin Resistance ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests ◽  
Resistance Rates ◽  
Prepubertal Girls

Abstract Background: To determine the prevalence of Haemophilus influenzae vulvovaginitis in prepubertal girls and the antimicrobial resistance of H.influenzae strains isolated from vulval specimens.Methods: Isolates of H.influenzae from vulval swabs of prepubertal girls with vulvovaginitis received at The Children's Hospital, Zhejiang University School of Medicine during 2016-2019 were studied. Vulval specimens were inoculated on Haemophilus selective chocolate agar. Antimicrobial susceptibility tests were performed using the disk diffusion method. A cefinase disk was used to detect β-lactamase. Results: A total of 4142 vulval specimens were received during the 4 years, 649 isolates of H. influenzae were isolated from 642 girls aged 6 months to 13 years, with a median of 5y. There were peaks of isolates from April to July seen in the vulval isolates. In total, the ampicillin resistance rate was 39.1% (250/640); 33.2% strains (211/636) were for β-lactamase-positive isolates, 6.6% strains (42/635) were β-lactamase-negative and ampicillin-resistant (BLNAR) isolates. The resistance rates of H. influenzae isolates to amoxycillin-clavulanic acid, ampicillin-sulbactam, cefuroxime, ceftriaxone, cefotaxime, meropenem, levofloxacin, sulfamethoxazole-trimethoprim, azithromycin, and chloramphenicol were 26.4%, 21.8%, 24.8%, 1.7%, 1.0%, 0.2%, 0%, 47.7%, 10.2%, and 1.1%, respectively. MDR was present in 41 (6.4%) of the 642 H. influenzae isolates, with the most prevalent MDR phenotype of ampicillin-sulfamethoxazole-trimethoprim-azithromycin resistance. Conclusions: H. influenzae is a common cause of vulvovaginitis in prepubertal girls. Laboratories should ensure that they include media appropriate for the isolation of H. influenzae. It’s worth noting of ampicillin resistance of H. influenzae in clinical management.

scholarly journals DETECTION OF AMINOGLYCOSIDE AND QUINOLONE RESISTANCE GENES AND EVALUATION OF POLYMYXIN B SUSCEPTIBILITY PROFILE IN ACINETOBACTER BAUMANNII CLINICAL ISOLATES IN TEHRAN, IRAN DURING 2015-2016

2018 ◽  
Vol 10 (1) ◽  
pp. e2018044 ◽  
Author(s):  
Mohsen Heidary
Keyword(s):  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Antimicrobial Susceptibility ◽  
Polymyxin B ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests

ABSTRACTAcinetobacter baumannii is an important opportunistic pathogen, responsible for approximately 10% of all gram-negative nosocomial infection. The main aims of this study were to detect aminoglycoside and quinolone resistance genes among clinical isolates of A. baumannii and determine the antimicrobial susceptibility profiles. Current study was performed from February 2015 to April 2016, at two teaching hospitals. One-hundred A. baumannii isolates were collected from different clinical samples. Antimicrobial susceptibility tests were done by disk diffusion method according to CLSI guidelines. Detection of the qnrA, anrB, qnrS, aac(3)-IIa, and aac(6′)-Ib genes was done by PCR assay. The results of antibiotic susceptibility tests indicated that polymyxin B was the most effective drug against isolates of A. baumannii and the isolates were most resistant to cefepime (97%), ceftriaxone (95%), and amikacin (82%). The aac(3)-IIa, aac(6′)-Ib, and qnrA genes were found in 45%, 50%, and 50% of isolates, respectively. However, qnrB and qnrS genes could not be detected in any A. baumannii isolate.This study showed that there is a high level of resistance genes among clinical isolates of A. baumannii circulating in hospitals in Iran. This high prevalence rate highlights the necessity for establishing rapid diagnostic assays, more antimicrobial susceptibility tests, continuous antibiotic resistance monitoring.Keywords: Acinetobacter baumannii, Aminoglycoside, Quinolone, Iran

scholarly journals Characterization of SCCmec, spa types and Multi Drug Resistant of methicillin-resistant Staphylococcus aureus isolates among inpatients and outpatients in a referral hospital in Shiraz, Iran

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Zahra Hashemizadeh ◽  
Nahal Hadi ◽  
Samane Mohebi ◽  
Davood Kalantar-Neyestanaki ◽  
Abdollah Bazargani
Keyword(s):  
Staphylococcus Aureus ◽  
Diffusion Method ◽  
Biochemical Tests ◽  
Spa Typing ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Tertiary Hospitals ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests ◽  
Spa Types

Abstract Objectives Molecular typing such as spa typing is used to control and prevent Staphylococcus aureus widespread in hospitals and communities. Hence, the aim of this study was to find the most common types of S. aureus strain circulating in Shiraz via spa and SCCmec typing methods. Results Total of 159 S. aureus isolates were collected from two tertiary hospitals in Shiraz. Isolates were identified by biochemical tests. Antimicrobial susceptibility tests were performed by standard disk diffusion method and then genetic analysis of bacteria was performed using SCCmec and spa typing. In this study 31.4% of the isolates were methicillin-resistant S. aureus. The majority of isolates were SSCmec type III. Spa type t030 was the most prominent type among MRSA strains. For the first time in Iran, spa003, t386, t1877, t314, t186, t1816, t304, t325, t345 were reported in this study. It was shown that there is a possibility that these spa types are native to this region. Our findings showed that SCCmec II, III and IV disseminate from hospital to community and vice versa. Thus, effective monitoring of MRSA in hospital and community is necessary.

scholarly journals Clonal spread of PER-1 and OXA-23 producing extensively drug resistant Acinetobacter baumannii during an outbreak in a burn intensive care unit in Tunisia

2020 ◽  
Author(s):  
Aymen Mabrouk ◽  
Yosra Chebbi ◽  
Anis Raddaoui ◽  
Asma Krir ◽  
Amen Allah Messadi ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Acinetobacter Baumannii ◽  
Genetic Relatedness ◽  
Burn Patients ◽  
Drug Resistant ◽  
Extensively Drug Resistant ◽  
Total Dna ◽  
Clonal Spread ◽  
Encoding Genes

AbstractExtensively drug resistant Acinetobacter baumannii (XDR-Ab), has emerged as an important pathogen in several outbreaks. The aim of our study was to investigate the eventual genetic relatedness of XDR-Ab strains recovered from burn patients and environment sites in the largest Tunisian Burn Intensive Care Unit (BICU) and to characterize β-lactamase encoding genes in these strains. Between March 04th, 2019 and April 22nd, 2019 an outbreak of XDR-Ab was suspected. Environmental screening was done. All isolates were screened by simplex PCR for β-lactamase genes. Genetic relatedness was determined by pulsed field gel electrophoresis (PFGE) of ApaI-digested total DNA. During the study period, 21 strains of A. baumannii were isolated in burn patients, mainly in blood culture (n = 7) and central vascular catheter (n = 6). All strains were susceptible to colistin but resistant to imipenem (n = 23), ciprofloxacin (n = 23), amikacin (n = 22), tigecyclin (n = 5) and rifampicin (n = 4). The blaOXA-51-like, blaOXA23, and blaADC genes were present in all strains. These resistance determinants were associated with blaPER-1 in 10 strains. The ISAba1 was inserted upstream of blaOXA-23 in all isolates. PFGE revealed two major clusters A (n = 11) and B (n = 5). This is the first description in Tunisia of clonally related PER-1 producing XDR-Ab in burn patients with probable environmental origin.

scholarly journals Categorizing susceptibility of clinical isolates of Candida auris to amphotericin B, caspofungin, and fluconazole utilizing the CLSI M44-A2 disk diffusion method

2021 ◽  
Author(s):  
Natalie S. Nunnally ◽  
Tajah Damm ◽  
Shawn R. Lockhart ◽  
Elizabeth L. Berkow
Keyword(s):  
Amphotericin B ◽  
Accurate Method ◽  
Clinical Isolates ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Broth Microdilution ◽  
Candida Auris ◽  
Disk Diffusion Method ◽  
Microdilution Method ◽  
Broth Microdilution Method

We evaluated the CLSI M44ed3E disk diffusion method in comparison with the CLSI M27ed4 broth microdilution method for caspofungin and fluconazole and the Etest method for amphotericin B to categorize susceptibility of 347 clinical isolates of Candida auris. Utilizing the zone diameter cutoffs established here we observed the overall categorial agreement between the two methods. For caspofungin, concordant results were observed for 98% of isolates with <1% very major and 1% major errors. For fluconazole, concordant results were observed for 91% of isolates with 1% very major and 8% major errors. For amphotericin B, concordant results were observed for 74% of isolates with <1% very major errors and 25% major errors. The disk diffusion approach provides an accurate method for determining the susceptibility of C. auris for caspofungin and fluconazole, and for identification of at least 75% of amphotericin B-susceptible isolates.

scholarly journals Major Bloodstream Infection-Causing Bacterial Pathogens and Their Antimicrobial Resistance in South Korea, 2017–2019: Phase I Report From Kor-GLASS

2022 ◽  
Vol 12 ◽  
Author(s):  
Dokyun Kim ◽  
Eun-Jeong Yoon ◽  
Jun Sung Hong ◽  
Min Hyuk Choi ◽  
Hyun Soo Kim ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Phase I ◽  
Bloodstream Infection ◽  
Molecular Mechanisms ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Glass Target ◽  
Blood Specimens

To monitor national antimicrobial resistance (AMR), the Korea Global AMR Surveillance System (Kor-GLASS) was established. This study analyzed bloodstream infection (BSI) cases from Kor-GLASS phase I from January 2017 to December 2019. Nine non-duplicated Kor-GLASS target pathogens, including Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, Streptococcus pneumoniae, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter spp., and Salmonella spp., were isolated from blood specimens from eight sentinel hospitals. Antimicrobial susceptibility testing, AMR genotyping, and strain typing were carried out. Among the 20,041 BSI cases, 15,171 cases were caused by one of the target pathogens, and 12,578 blood isolates were collected for the study. Half (1,059/2,134) of S. aureus isolates were resistant to cefoxitin, and 38.1% (333/873) of E. faecium isolates were resistant to vancomycin. Beta-lactamase-non-producing ampicillin-resistant and penicillin-resistant E. faecalis isolates by disk diffusion method were identified, but the isolates were confirmed as ampicillin-susceptible by broth microdilution method. Among E. coli, an increasing number of isolates carried the blaCTX–M–27 gene, and the ertapenem resistance in 1.4% (30/2,110) of K. pneumoniae isolates was mostly (23/30) conferred by K. pneumoniae carbapenemases. A quarter (108/488) of P. aeruginosa isolates were resistant to meropenem, and 30.5% (33/108) of those carried acquired carbapenemase genes. Over 90% (542/599) of A. baumannii isolates were imipenem-resistant, and all except one harbored the blaOXA–23 gene. Kor-GLASS provided comprehensive AMR surveillance data, and the defined molecular mechanisms of resistance helped us to better understand AMR epidemiology. Comparative analysis with other GLASS-enrolled countries is possible owing to the harmonized system provided by GLASS.

scholarly journals Dissemination of Plasmid-Mediated Aminoglycoside-Modifying Enzymes Among MDR Acinetobacter baumannii Isolates from a Tertiary Care Egyptian Hospital

2020 ◽  
Vol 14 (1) ◽  
pp. 98-106
Author(s):  
Mahmoud M. Tawfick ◽  
Hamada F. Rady ◽  
Mervat I. El-Borhamy ◽  
Anwar D. Maraqa
Keyword(s):  
Acinetobacter Baumannii ◽  
Tertiary Care ◽  
Multidrug Resistant ◽  
Resistance Rate ◽  
Care Hospital ◽  
Aminoglycoside Resistance ◽  
Antimicrobial Susceptibility Pattern ◽  
Pcr Method ◽  
Resistance Rates ◽  
Encoding Genes

Background: Acinetobacter baumannii is one of the most challenging multidrug-resistant (MDR) nosocomial pathogens worldwide. Aminoglycosides are used for the treatment of A. baumannii infections, however, resistance to aminoglycosides is currently emerging, limiting therapeutic choices. Objective: In this study, the prevalence of aminoglycoside resistance and plasmid-mediated mechanisms of aminoglycoside resistance were investigated in A. baumannii clinical isolates collected from ICU patients at a tertiary care hospital in Egypt. Methods: The automated Vitek 2 system was used to identify A. baumannii species and determination of the antimicrobial susceptibility pattern. The identification of A. baumannii was confirmed by the detection of the blaOXA-51-like gene intrinsic to this species. Minimum Inhibitory Concentration (MIC) of gentamicin was determined using E-test following the CLSI breakpoints. Isolates were screened for the prevalence and diversity of the plasmid-carried aminoglycoside-modifying enzymes encoding genes aacC1, aadA1, aadB and aphA6. For genetic diversity analysis, the ERIC-PCR method was performed. Results: All A. baumannii isolates were MDR with high resistance rates to tested antimicrobials. The resistance rate to gentamicin was 92.9% with elevated MICs (≥ 32 μg/mL). The gentamicin-resistant isolates harboured one or more of the studied genes with the prevalence of aphA6 (81%). ERIC-based genotyping revealed that there was no evidence of A. baumannii clonal dissemination among isolates. Conclusion: The study concluded that MDR A. baumannii isolates were highly resistant to gentamicin. The plasmid-carried aminoglycoside-modifying enzymes encoding genes were disseminated among isolates with the AphA6 gene, which was the most prevalent one. The acquisition of more than one aminoglycoside resistance gene was associated with an elevated MIC of gentamicin. Thus, regular surveillance studies of the emerging resistance to antimicrobials and strict measures to control the dissemination of resistance determinants genes are warranted.

Sign in / Sign up

Export Citation Format

Share Document