scholarly journals Antimicrobial Resistance and Genomic Characterization of Six New Sequence Types in Multidrug-Resistant Pseudomonas aeruginosa Clinical Isolates from Pakistan

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1386
Author(s):  
Sidra Irum ◽  
Kanwal Naz ◽  
Nimat Ullah ◽  
Zeeshan Mustafa ◽  
Amjad Ali ◽  
...  

Pseudomonas aeruginosa (P. aeruginosa) is a major bacterial pathogen associated with a variety of infections with high mortality rates. Most of the clinical P. aeruginosa isolates belong to a limited number of genetic subgroups characterized by multiple housekeeping genes’ sequences (usually 5–7) through the Multi-Locus Sequence Typing (MLST) scheme. The emergence and dissemination of novel multidrug-resistant (MDR) sequence types (ST) in P. aeruginosa pose serious clinical concerns. We performed whole-genome sequencing on a cohort (n = 160) of MDR P. aeruginosa isolates collected from a tertiary care hospital lab in Pakistan and found six isolates belonging to six unique MLST allelic profiles. The genomes were submitted to the PubMLST database and new ST numbers (ST3493, ST3494, ST3472, ST3489, ST3491, and ST3492) were assigned to the respective allele combinations. MLST and core-genome-based phylogenetic analysis confirmed the divergence of these isolates and positioned them in separate branches. Analysis of the resistome of the new STs isolates revealed the presence of genes blaOXA-50, blaPAO, blaPDC, blaVIM-2, aph(3′)-IIb, aac(6′)-II, aac(3)-Id, fosA, catB7, dfrB2, crpP, merP and a number of missense and frame-shift mutations in chromosomal genes conferring resistance to various antipseudomonal antibiotics. The exoS, exoT, pvdE, rhlI, rhlR, lasA, lasB, lasI, and lasR genes were the most prevalent virulence-related genes among the new ST isolates. The different genotypic features revealed the adaptation of these new clones to a variety of infections by various mutations in genes affecting antimicrobial resistance, quorum sensing and biofilm formation. Close monitoring of these antibiotic-resistant pathogens and surveillance mechanisms needs to be adopted to reduce their spread to the healthcare facilities of Pakistan. We believe that these strains can be used as reference strains for future comparative analysis of isolates belonging to the same STs.

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S440-S440
Author(s):  
Jorge A Ramos-Castaneda ◽  
Matthew L Faron ◽  
Joshua Hyke ◽  
Blake W Buchan ◽  
Rahul Nanchal ◽  
...  

Abstract Background New evidence shows the relevance of sink drains in the horizontal transmission of multidrug-resistant organisms. We recently demonstrated that a peroxide-based disinfectant (product B) was better than bleach at disinfecting sink drains; however, we did not determine the duration of this effect. In this study, we evaluate the duration of bacterial reduction in sink drains treated with product B and compared it to an enhanced hydrogen peroxide agent (product A). Methods Testing was performed in a 26-bed medical intensive care unit at a 566-bed tertiary care hospital in Milwaukee, WI. Two disinfectants were compared: product A (hydrogen peroxide, octanoic acid, and peroxyacetic acid; Virasept, Ecolab) and product B (hydrogen peroxide-based disinfectant; Peroxide Multi Surface Cleaner and Disinfectant, Ecolab). Sinks were randomly assigned to product A, product B, and control (no disinfection). On day 0, baseline cultures were obtained and disinfectant agents were applied. On post-intervention days 1, 3, 5, and, 7, samples from each drain were collected using E-swabs (Copan, Italy). Quantitation of Gram-negative burden was determined by serial dilution in saline plated to MacConkey agar and dilutions that contained 20–200 colonies were used for bacterial colony-forming units (CFU). Multivariate multiple linear regression and analysis of variance were used to compare mean Ln(1+CFU) between groups using R v3.5.0. Environmental sampling, cultures, and statistical analyses were performed blinded to the disinfected used. Results All three groups had similar CFU counts at baseline (P > 0.05). On day 1, a statistically significant reduction in bacterial CFUs was observed in the group treated with product A compared with sinks treated with product B (P = 0.04) or the control group (P < 0.01). The same differences were observed on day 3 post-intervention. There were no significant reductions on days 5 and 7. Conclusion Product A was the most effective product at disinfecting sink drains but its effect disappeared at 5 days post-disinfection. These results suggest that treating sink drains every 5 days with a hydrogen peroxide mixture would be ideal for healthcare facilities dealing with sink drain contamination. Disclosures All authors: No reported disclosures.


2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Silpi Basak ◽  
Priyanka Singh ◽  
Monali Rajurkar

Background and Objective. Antimicrobial resistance is now a major challenge to clinicians for treating patients. Hence, this short term study was undertaken to detect the incidence of multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR) bacterial isolates in a tertiary care hospital.Material and Methods. The clinical samples were cultured and bacterial strains were identified in the department of microbiology. The antibiotic susceptibility profile of different bacterial isolates was studied to detect MDR, XDR, and PDR bacteria.Results. The antibiotic susceptibility profile of 1060 bacterial strains was studied. 393 (37.1%) bacterial strains were MDR, 146 (13.8%) strains were XDR, and no PDR was isolated. All (100%) Gram negative bacterial strains were sensitive to colistin whereas all (100%) Gram positive bacterial strains were sensitive to vancomycin.Conclusion. Close monitoring of MDR, XDR, or even PDR must be done by all clinical microbiology laboratories to implement effective measures to reduce the menace of antimicrobial resistance.


2019 ◽  
Vol 21 (2) ◽  
pp. 110-116
Author(s):  
Rajani Shrestha ◽  
N. Nayak ◽  
D.R. Bhatta ◽  
D. Hamal ◽  
S.H. Subramanya ◽  
...  

Clinical isolates of Pseudomonas aeruginosa often exhibit multidrug resistance due to their inherent ability to form biofilms. Drug resistance in Ps. aeruginosa is a major clinical problem, especially in the management of patients with nosocomial infections and those admitted to ICUs with indwelling medical devices. To evaluate the biofilm forming abilities of the clinical isolates of Ps. aeruginosa and to correlate biofilm formation with antibiotic resistance. A total of 90 consecutive isolates of Ps. aeruginosa obtained from various specimens collected from patients visiting the Manipal Teaching Hospital, Pokhara, Nepal between January 2018 - October 2018 were studied. Isolates were identified by standard microbiological methods. Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion method. All the isolates were tested for their biofilm forming abilities by employing the tissue culture plate assay. Of the 90 Ps. aeruginosa isolates, maximum i.e 42 (46.6%) were from patients in the age group of > 50 years. Majority (30; 33.3%) of the isolates were obtained from sputum samples. However, percentage isolation from other specimens like urine, endotracheal tube (ETT), pus, eye specimens and blood were 18.9%, 16.7%, 16.7%, 7.8% and 6.7% respectively. All the isolates were sensitive to polymixin B and colistin, 91.1% of the organisms were sensitive to imipenem, and more than 80% to aminoglycosides (80% to gentamicin, 83.3% to amikacin). A total of 29 (32.2%) organisms were biofilm producers. Maximum numbers of biofilm producing strains were obtained from ETT (8 of 15; 53.3%), pus (8 of 15; 53.3%) and blood (2 of 6; 33.3%) i.e from all invasive sites. None of the isolates from noninvasive specimens such as conjunctival swabs were biofilm positive. Significantly higher numbers of biofilm producers (23 of 29; 79.3%) were found to be multidrug resistant as compared to non-biofilm (6 of 61; 9.8%) producers (p=0.000). Ps. aeruginosa colonization leading to biofilm formation in deep seated tissues and on indwelling devices is a therapeutic challenge as majority of the isolates would be recalcitrant to commonly used antipseudomonal drugs. Effective monitoring of drug resistance patterns in all Pseudomonas clinical isolates should be a prerequisite for successful patient management.


Author(s):  
Hemin E. Othman ◽  
Eric L. Miller ◽  
Jaladet Ms. Jubrael ◽  
Ian S. Roberts

Introduction: The exoU gene, a marker for highly virulent strains of Pseudomonas aeruginosa, is the major contributor to a wide variety of healthcare-associated infections. Methods: In this study, the antibiotic susceptibility profile, prevalence and genotyping of exoU+ P. aeruginosa were demonstrated. A total of 101 isolates of P. aeruginosa were analysed from different clinical and environmental sources. Results: The antibiotic susceptibility profile classified these isolates as extensively drug resistant (35.6%), multidrug resistant (40.5%) and non-multidrug resistant (23.7%). The prevalence of exoU gene was screened by PCR and 23 exoU+ genotypes were detected which all were clinical isolates. Multilocus sequence typing (MLST) analysis of seven loci assigned these exoU+ genotypes to 21 sequence types (STs) from which 16 new STs were identified. The prevalent STs were ST-308 and ST-235. Phylogenetic analysis using the concatenated nucleotide sequences of the seven housekeeping genes, exoUand the ITS region differentiated these exoU+ strains into five main groups. However, distinct evolutionary origins for some new sequence types were also indicated. Conclusions: The studied isolates showed the coexistence of exoU- and exoU+ genotypes of clinical P. aeruginosa in Kurdistan with a majority of MDR and XDR pattern. The prevalent STs found in other hospitals worldwide and at the international level.


2013 ◽  
Vol 14 (1) ◽  
pp. 28-32 ◽  
Author(s):  
Azizun Nahar ◽  
Shaheda Anwar ◽  
Md. Ruhul Amin Miah

Purpose: The purpose of this study was to detect biofilm formation in clinical isolates of Acinetobacter species and to observe correlation between biofilm formation and antimicrobial resistance among Acinetobacter isolates. Methods: Two hundred fifty six clinical samples collected from patients who were admitted in Intensive Care Unit (ICU) and on device, patients from Surgery, Medicine, Gynae & Obs and Urology department of Bangabandhu Sheikh Mujib Medical University (BSMMU) and from Burn unit of Dhaka Medical College Hospital were included in this study. Biofilm formation and antibiotyping were performed for the isolates of Acinetobacter species recovered from clinical samples including tracheal aspirates, blood, urine, wound swab, pus, throat swab, endotracheal tubes, burn samples, ascitic fluid, sputum, aural swab, oral swab, cerebrospinal fluid, and catheter tip. Correlation of biofilm formation with antimicrobial resistance pattern among Acinetobacter isolates were also observed in this study. Result: A total of 256 various specimens were studied of which 95 Intensive Care Unit (ICU) and 161 Non ICU samples. Out of 95 ICU and 161 Non ICU samples, Acinetobacter species were isolated from 32 (33.7%) and 20(12.4%) respectively. From 32 ICU and 20 Non ICU Acinetobacter isolates, 28 (87.5%) and 11 (55%) were biofilm producers. Biofilm forming capacity of Acinetobacter species was significantly (p<0.008) greater in ICU than in Non ICU isolates. In both ICU and Non ICU isolates, biofilm forming Acinetobacter species were 100% resistant to amoxicillin, ceftriaxone, ceftazidime, cefotaxime, cefuroxime, and aztreonam. Resistance to antibiotics such as gentamicin, amikacin, netilmicin, ciprofloxacin and imipenem was higher among biofilm forming Acinetobacter isolates in ICU than Non ICU isolates. Susceptibility to colistin was 100% in Non ICU isolates but in ICU it showed 7.1% resistance. Conclusions: This investigation showed that most of the clinical isolates of Acinetobacter species were biofilm producers especially from ICU samples and they were multidrug resistant. Even polymixin resistant Acinetobacter isolates are slowly emerging. This is very alerming for us that biofilm forming multidrug resistant Acinetobacter species represents a severe threat in the treatment of hospitalized patients. So, antibiotic policy and guidelines are essential to eliminate major outbreak in future.DOI: http://dx.doi.org/10.3329/jom.v14i1.14533 J MEDICINE 2013; 14 : 28-32


2012 ◽  
Vol 4 (01) ◽  
pp. 039-042 ◽  
Author(s):  
Simit H Kumar ◽  
Anuradha S De ◽  
Sujata M Baveja ◽  
Madhuri A Gore

ABSTRACT Introduction: The production of Metallo-β-lactamases (MBLs) is one of the resistance mechanisms of Pseudomonas aeruginosa and Acinetobacter species. There is not much Indian data on the prevalence of MBLs in burns and surgical wards. Materials and Methods: A total of 145 non-duplicate isolates of carbapenem-resistant Pseudomonas aeruginosa and Acinetobacter species, isolated from pus/wound swabs and endotracheal secretions from burns and surgical wards, were tested for MBL production by modified ethylene diamine tetra acetic acid (EDTA) disc synergy and double disc synergy tests. Results: Prevalence of MBLs was 26.9% by both the above tests. All MBL-positive isolates were multidrug resistant. Only 6.06% (2/33) P.aeruginosa and 16.67% (1/06) Acinetobacter species were susceptible to piperacillin-tazobactam and netilmycin, respectively. These patients had multiple risk factors like >8 days hospital stay, catheterization, IV lines, previous antibiotic use, mechanical ventilation, etc. Graft application and surgical intervention were significant risk factors in MBL-positive patients. Overall mortality in MBL-positive patients was 34.21%. Conclusion: Emergence of MBL-producing Pseudomonas aeruginosa and Acinetobacter species in this hospital is alarming, which reflect excessive use of carbapenems and at the same time, pose a therapeutic challenge to clinicians as well as to microbiologists. Therefore, a strict antibiotic policy and implementation of proper infection control practices will go a long way to prevent further spread of MBLs. Detection of MBLs should also become mandatory in all hospitals.


2020 ◽  
Author(s):  
Nousheen Iqbal ◽  
Muhammad Irfan ◽  
Mustafa bin Ali Zuabairi ◽  
Maaha Ayub ◽  
Safia Awan ◽  
...  

Abstract Background:There is limited data available about allergic bronchopulmonary aspergillosis (ABPA) from Pakistan. The aim of the study was to describe the radiological and microbiological profile of ABPA patients presenting to outpatient pulmonary clinic of a tertiary care hospital, Karachi, Pakistan.MethodsA retrospective study was conducted on ABPA patients who presented to pulmonary outpatient clinic, Aga Khan University Hospital, Karachi, Pakistan from January 2017 to December 2018. Data was collected on microbiology and radiology features on predesigned proforma.ResultsA total 7759 asthmatic patients presented at outpatient pulmonology clinic during study period. Of the 245 patients labeled as ABPA, 167 patients fulfilled the inclusion criteria and 91 (54.5%) were female (mean age 41.9 ± 13.0 years). High resolution CT scan (HRCT) chest was available in 126 patients. Of these, 104 (82.5%) patients had bronchiectasis. Central bronchiectasis was noted in 98 (94.2%), mucus plugging in 71 (56.3%) and hyperinflation was seen in 30 (23.4%) patients. Microbiological testing was available in 103/167 (61.7%) patients. The most common bacterial pathogen was Pseudomonas aeruginosa 32 (31.1%) followed by Hemophilus influenzae 16 (15.5%) and Moraxella catarrhalis 7(9.7%). Aspergillus fumigatus 17(23.6%) was the most common mold followed by Aspergillus flavus 16 (22.2%) and Aspergillus niger 11 (15.3%). Co infection (bacterial and fungal) was found in 18 (17.45%) patients.ConclusionBronchiectasis was frequently observed in our cohort of patients with ABPA. Pseudomonas aeruginosa was found to be common among bacterial pathogens. Isolation of fungus is not uncommon in these patients.


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