scholarly journals Drug Resistance Mechanism among Acinetobacter Species

2021 ◽  
Author(s):  
S. Jayashree ◽  
K.G. Rajeshwari ◽  
Mita D. Wadekar
Keyword(s):  
Drug Resistance ◽  
Resistance Mechanism ◽  
Multidrug Resistant ◽  
Hospital Environment ◽  
Diffusion Method ◽  
Multi Drug Resistance ◽  
Intrinsic Resistance ◽  
Acinetobacter Species ◽  
Beta Lactamases ◽  
Resistant Strains

Acinetobacter species cause infections that are difficult to control due to multi-drug resistance and are noted for their intrinsic resistance to antibiotics and for their ability to acquire genes encoding resistance for the production of beta-lactamases and Aminoglycoside-modifying enzymes. MBLs are molecular class B and functional group 3 beta-lactamases which have the capability of hydrolyzing all β-lactams except the Monobactam, Aztreonam. Of several MBLs, only IMP, VIM and SIM types have been detected in these species. To analyze the antibiotic resistance patterns among Acinetobacter isolates and to detect Carbapenemase and MBL among MDR Acinetobacter isolates. The descriptive study of all phenotypically identified strains and multidrug-resistant strains of Acinetobacter species was conducted. A total of 303 isolates were isolated from various samples. They were processed and identified by standard Microbiological procedures. The antibiotics susceptibility testing was performed by Kirby- Bauer disc diffusion method using CLSI guidelines. Carbapenemase production was detected by employing 3 phenotypic test methods (MHT, CDM and DDST). Of 6355 samples processed, 303 were found to be Acinetobacter species, among those 50 were multidrug-resistant strains. The highest isolation of MDR Acinetobacter was from endotracheal tube tip (42%) and pus sample (32%). The majority of MDR Acinetobacter infection was found in male patients 36 (72%) compared to female patients 14 (28%). The majority of the strains were isolated from patients >/ 60 years of age group (%). A number of these isolates were more from ICU wards (30%) followed by Surgery wards (24%). Higher resistance for the Piperacillin/tazobactam ((82%), followed by Ceftazidime (80%), Imipenem (76%) etc. and the most susceptible drug was found to be the Tigecycline (82%) followed by Colistin (80%). Carbapenemase production was detected by MHT and 24 (48%) isolates were MHT positive. MBL production was detected by CDM and 34 (68%) isolates were CDM positive and by DDST 30 (60%) isolates were positive. Acinetobacter species are increasingly important nosocomial pathogens and are capable of rapid adaptation to the hospital environment. The variety of potential source of contamination or infection with these species in the hospital environment makes control of outbreaks caused by these difficult.

scholarly journals Phenotypic Characterization of Extended-Spectrum Beta-Lactamases and Metallo-Beta-Lactamase of Multi Drug Resistant Acinetobacter baumannii Causing Nosocomial Infections in Erbil City

2020 ◽  
Vol 30 (4) ◽  
pp. 51
Author(s):  
Sakar Bakr Smail ◽  
Kamal I. AL-OTRACHI
Keyword(s):  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Phenotypic Characterization ◽  
Multi Drug Resistance ◽  
Beta Lactamase ◽  
Beta Lactamases ◽  
Extended Spectrum ◽  
Extended Spectrum Beta Lactamases

Background: Resistance to broad‑spectrum beta‑lactams, mediated by extended‑spectrum beta‑lactamases, and metallo‑beta‑lactamase enzymes, is an increasing problem worldwide. The main aim is to study phenotypic characterization of extended‑spectrum beta‑lactamases and metallo‑beta‑lactamase multidrug resistant Acinetobacter baumannii in Erbil City. Materials and Methods: A total of 112 Acinetobacter baumannii isolations were collected from patients of all age groups from clinical specimens sputum, blood, pus, wound swab, urine and body fluids (Pleural fluid and cerebrospinal fluid) collected from different medical wards and intensive care unit departments of hospitals in Erbil City for a period of one year from march 2018--march 2019. Isolates were tested for the presence of extended‑spectrum beta‑lactamases and metallo‑beta‑lactamase. Detection of extended‑spectrum beta‑lactamases was done by the combined disk diffusion method according to Clinical and Laboratory Standards Institute guidelines, while metallo‑beta‑lactamase was detected by meropenem and imipenem combined with ethylenediaminetetraacetic acid disk method. Results: 25% (28) Acinetobacter baumannii isolates were positive for extended‑spectrum beta‑lactamases, while 100 % (112) were metallo‑beta‑lactamase producers. Conclusion: Acinetobacter baumannii is becoming a global medical challenge due to the emergence of multi-drug resistance. Newer beta lactamase is a matter of concern as they are developing rapidly and lead to treatment failure. Carbapenems are known to be effective therapeutic agents for Acinetobacter baumannii infections and its resistance limits the use to polymyxins and colistin. Several new medicines are still in research and combination of drug therapy is being currently used in the hospitals together with ours to treat multidrug resistant Acinetobacter baumannii infections.

scholarly journals Antibiotic Resistance of Uropathogens Isolated from Patients Hospitalized in District Hospital in Central Poland in 2020

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 447
Author(s):  
Barbara Kot ◽  
Agata Grużewska ◽  
Piotr Szweda ◽  
Jolanta Wicha ◽  
Urszula Parulska
Keyword(s):  
Antibiotic Resistance ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Beta Lactamases ◽  
E Coli ◽  
Central Poland ◽  
Resistance Patterns ◽  
Extended Spectrum Beta Lactamases ◽  
Tract Infections

The aim of this study was to determine antibiotic resistance patterns and the prevalence of uropathogenes causing urinary tract infections (UTIs) in patients hospitalized in January–June 2020 in central Poland. Antimicrobial susceptibility testing was performed using the disk-diffusion method. Escherichia coli (52.2%), Klebsiella pneumoniae (13.7%), Enterococcus faecalis (9.3%), E. faecium (6.2%), and Proteus mirabilis (4,3%) were most commonly isolated from urine samples. E. coli was significantly more frequent in women (58.6%) (p = 0.0089) and in the age group 0–18, while K. pneumoniae was more frequent in men (24.4%) (p = 0.0119) and in individuals aged 40–60 and >60. Gram-negative species showed resistance to ampicillin. K. pneumoniae were resistant to amoxicillin plus clavulanic acid (75.0%), piperacillin plus tazobactam (76.2%), cefotaxime (76.2%), cefuroxime (81.0%), ciprofloxacin (81.0%), and trimethoprim plus sulphamethoxazole (81.0%). Carbapenems were effective against all E. coli and P. mirabilis. Some K. pneumoniae (13.6%) produced metallo-β-lactamases (MBLs). E. coli (22.6%), K. pneumoniae (81.8%), and all E. faecium were multidrug-resistant (MDR). Some E. coli (26.2%), K. pneumoniae (63.6%), and P. mirabilis (14.3%) isolates produced extended-spectrum beta-lactamases (ESBL). Vancomycin-resistant E. faecium was also found. This study showed that the possibilities of UTIs therapy using available antibiotics become limited due to the increasing number of antibiotic-resistant uropathogens.

scholarly journals Constraints of Drug Resistance in Mycobacterium tuberculosis - Prospects for Pharmacological Reversion of Susceptibility to Antibiotics

2017 ◽  
Vol 8 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Aleksandr I. Ilin ◽  
Murat E. Kulmanov ◽  
Ilya S. Korotetskiy ◽  
Marina V. Lankina ◽  
Gulshara K. Akhmetova ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Genetic Heterogeneity ◽  
Multidrug Resistant ◽  
Resistance Mutations ◽  
General Increase ◽  
Drug Induced ◽  
Mdr Tb ◽  
Resistant Strains

Emergence of multidrug resistant strains ofMycobacterium tuberculosis(MDR-TB) threatens humanity. This problem was complicated by the crisis in development of new anti-tuberculosis antibiotics. Induced reversion of drug resistance seems promising to overcome the problem. Successful clinical trial of a new anti-tuberculosis nanomolecular complex FS-1 has demonstrated prospectively of this approach in combating MDR-TB. Several clinical MDR-TB cultures were isolated from sputum samples prior and in the process of the clinical trial. Every isolate was tested for susceptibility to antibiotics and then they were sequenced for comparative genomics. It was found that the treatment with FS-1 caused an increase in the number of antibiotic susceptible strains among Mtb isolates that was associated with a general increase of genetic heterogeneity of the isolates. Observed impairing of phthiocerol dimycocerosate biosynthesis by disruptive mutations inppsACDsubunits indicated a possible virulence remission for the sake of persistence. It was hypothesized that the FS-1 treatment eradicated the most drug resistant Mtb variants from the population by aggravating the fitness cost of drug resistance mutations. Analysis of distribution of these mutations in the global Mtb population revealed that many of them were incompatible with each other and dependent on allelic states of many other polymorphic loci. The latter discovery may explain the negative correlation between the genetic heterogeneity of the population and the level of drug tolerance. To the best of our knowledge, this work was the first experimental confirmation of the drug induced antibiotic resistance reversion by the induced synergy mechanism that previously was predicted theoretically.

scholarly journals Prevalence of Extended Spectrum Beta Lactamases (ESBL) and Metallo Beta Lactamases (MBL) Mediated Resistance in Gram Negative Bacterial Pathogens

2018 ◽  
Vol 4 ◽  
pp. 49-54 ◽  
Author(s):  
Pramila Pathak ◽  
Nandalal Jaishi ◽  
Binod Kumar Yadav ◽  
Pradeep Kumar Shah
Keyword(s):  
Drug Resistance ◽  
Hospital Setting ◽  
Multi Drug Resistance ◽  
Microbiological Analysis ◽  
Bacterial Isolates ◽  
Biochemical Tests ◽  
Gram Negative ◽  
Beta Lactamases ◽  
Clinical Specimens ◽  
Extended Spectrum

Objectives: This study was conducted to determine the prevalence of multi-drug resistance (MDR) along with Extended Spectrum β-lactamase (ESBL) and Metallo β-lactamase (MBL) producing gram negative bacterial isolates among the patients attending Shahid Gangalal National Heart Centre, Kathmandu, Nepal.Methods: This cross-sectional study was carried out from June to December; 2016. Altogether 977 clinical specimens were processed for analysis of bacteriological profile and the isolates were identified by culture, morphological and biochemical tests. Antibiotic susceptibility testing of the isolates was performed by Kirby Bauer disc diffusion methods following Clinical and Laboratories Standard Institute guideline and the isolates were tested for ESBL and MBL by combined disk method.Results: out of 977 clinical specimens, 254 (25.99%) were found to be gram negative bacterial isolates, among them Klebsiella pneumoniae 83 (32.67%) was the most predominant organism followed by E. coli 51 (20.07%), Pseudomonas aeruginosa 36 (14.17%), K. oxytoca 32 (12.59%), Proteus mirabilis 13 (5.11%) and P. vulgaris 13 (5.11%), Acinetobacter spp. 11 (4.33%), Citrobacter spp. 10 (3.93%) and Enterobacter spp. 5 (1.96%) respectively. 83 (32.67%) isolates were found to be MDR, 38(14.96%) were positive for ESBL while 19 (7.48%) were MBL producer.Conclusion: The determent drug resistance among ESBL and MBL producers, reflect the extensive use of antibiotics possessing difficulties in therapeutic potions in hospital setting which might be overcome by proper microbiological analysis of pathogenic isolates and judicious use of antibiotics for emergence of resistance strains.

scholarly journals Cockroaches as a Source of High Bacterial Pathogens with Multidrug Resistant Strains in Gondar Town, Ethiopia

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Feleke Moges ◽  
Setegn Eshetie ◽  
Mengistu Endris ◽  
Kahsay Huruy ◽  
Dagnachew Muluye ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Bacterial Species ◽  
Multidrug Resistant ◽  
Resistance Rate ◽  
Control Measures ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Gondar Town ◽  
Resistant Strains ◽  
And Control

Background. Cockroaches are source of bacterial infections and this study was aimed to assess bacterial isolates and their antimicrobial profiles from cockroaches in Gondar town, Ethiopia.Methods. A total of 60 cockroaches were collected from March 1 to May 30, 2014, in Gondar town. Bacterial species were isolated from external and internal parts of cockroaches. Disk diffusion method was used to determine antibiotic susceptibility patterns. Data were entered and analyzed by using SPSS version 20;Pvalues <0.005 were considered as statistically significant.Results. Of 181 identified bacteria species, 110 (60.8%) and 71 (39.2%) were identified from external and internal parts of cockroaches, respectively.Klebsiella pneumoniae32 (17.7%),Escherichia coli29 (16%), andCitrobacterspp. 27 (15%) were the predominant isolates. High resistance rate was observed to cotrimoxazole, 60 (33.1%), and least resistance rate was noted to ciprofloxacin, 2 (1.1%). Additionally, 116 (64.1%) of the isolates were MDR strains;Salmonellaspp. were the leading MDR isolates (100%) followed byEnterobacter(90.5%) andShigellaspp. (76.9%).Conclusion. Cockroaches are the potential source of bacteria pathogens with multidrug resistant strains and hence effective preventive and control measures are required to minimize cockroach related infections.

scholarly journals UDP-Glycosyltransferases and Albendazole Metabolism in the Juvenile Stages of Haemonchus contortus

2020 ◽  
Vol 11 ◽  
Author(s):  
Pavlína Kellerová ◽  
Martina Navrátilová ◽  
Linh Thuy Nguyen ◽  
Diana Dimunová ◽  
Lucie Raisová Stuchlíková ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Resistant Strain ◽  
Haemonchus Contortus ◽  
Resistance Mechanism ◽  
Constitutive Expression ◽  
Primary Metabolite ◽  
Resistance Development ◽  
Enhanced Solubility ◽  
Juvenile Stages ◽  
Resistant Strains

The nematode Haemonchus contortus, a gastrointestinal parasite of ruminants, can severely burden livestock production. Although anthelmintics are the mainstay in the treatment of haemonchosis, their efficacy diminishes due to drug-resistance development in H. contortus. An increased anthelmintics inactivation via biotransformation belongs to a significant drug-resistance mechanism in H. contortus. UDP-glycosyltransferases (UGTs) participate in the metabolic inactivation of anthelmintics and other xenobiotic substrates through their conjugation with activated sugar, which drives the elimination of the xenobiotics due to enhanced solubility. The UGTs family, in terms of the biotransformation of commonly used anthelmintics, has been well described in adults as a target stage. In contrast, the free-living juvenile stages of H. contortus have attracted less attention. The expression of UGTs considerably varies throughout the life cycle of the juvenile nematodes, suggesting their different roles. Furthermore, the constitutive expression in a susceptible strain with two resistant strains shows several resistance-related changes in UGTs expression, and the exposure of juvenile stages of H. contortus to albendazole (ABZ) and ABZ-sulfoxide (ABZSO; in sublethal concentrations) leads to the increased expression of several UGTs. The anthelmintic drug ABZ and its primary metabolite ABZSO biotransformation, tested in the juvenile stages, shows significant differences between susceptible and resistant strain. Moreover, higher amounts of glycosidated metabolites of ABZ are formed in the resistant strain. Our results show similarly, as in adults, the UGTs and glycosidations significant for resistance-related differences in ABZ biotransformation and warrant further investigation in their individual functions.

scholarly journals Drug Resistance and Biofilm Production among Pseudomonas aeruginosa Clinical Isolates in a Tertiary Care Hospital of Nepal

2019 ◽  
Vol 21 (2) ◽  
pp. 110-116
Author(s):  
Rajani Shrestha ◽  
N. Nayak ◽  
D.R. Bhatta ◽  
D. Hamal ◽  
S.H. Subramanya ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Drug Resistance ◽  
Biofilm Formation ◽  
Tertiary Care ◽  
Clinical Problem ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Care Hospital ◽  
Microbiological Methods

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.

scholarly journals Impact of an Intervention to Control Imipenem-Resistant Acinetobacter baumannii and Its Resistance Mechanisms: An 8-Year Survey

2021 ◽  
Vol 11 ◽  
Author(s):  
Lida Chen ◽  
Pinghai Tan ◽  
Jianming Zeng ◽  
Xuegao Yu ◽  
Yimei Cai ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Acinetobacter Baumannii ◽  
Bacterial Resistance ◽  
Efflux Pump ◽  
Resistance Mechanism ◽  
Resistance Mechanisms ◽  
Multi Drug Resistance ◽  
Minimal Inhibitory Concentrations ◽  
Resistance Rates ◽  
The Impact

BackgroundThis study aimed to examine the impact of an intervention carried out in 2011 to combat multi-drug resistance and outbreaks of imipenem-resistant Acinetobacter baumannii (IRAB), and to explore its resistance mechanism.MethodsA total of 2572 isolates of A. baumannii, including 1673 IRAB isolates, were collected between 2007 and 2014. An intervention was implemented to control A. baumannii resistance and outbreaks. Antimicrobial susceptibility was tested by calculating minimal inhibitory concentrations (MICs), and outbreaks were typed using pulsed-field gel electrophoresis (PFGE). Resistance mechanisms were explored by polymerase chain reaction (PCR) and whole genome sequencing (WGS).ResultsFollowing the intervention in 2011, the resistance rates of A. baumannii to almost all tested antibiotics decreased, from 85.3 to 72.6% for imipenem, 100 to 80.8% for ceftriaxone, and 45.0 to 6.9% for tigecycline. The intervention resulted in a decrease in the number (seven to five), duration (8–3 months), and departments (five to three) affected by outbreaks; no outbreaks occurred in 2011. After the intervention, only blaAMPC (76.47 to 100%) and blaTEM–1 (75.74 to 96.92%) increased (P &lt; 0.0001); whereas blaGES–1 (32.35 to 3.07%), blaPER–1 (21.32 to 1.54%), blaOXA–58 (60.29 to 1.54%), carO (37.50 to 7.69%), and adeB (9.56 to 3.08%) decreased (P &lt; 0.0001). Interestingly, the frequency of class B β-lactamase genes decreased from 91.18% (blaSPM–1) and 61.03% (blaIMP–1) to 0%, while that of class D blaOXA–23 increased to 96.92% (P &lt; 0.0001). WGS showed that the major PFGE types causing outbreaks each year (type 01, 11, 18, 23, 26, and 31) carried the same resistance genes (blaKPC–1, blaADC–25, blaOXA–66, and adeABC), AdeR-S mutations (G186V and A136V), and a partially blocked porin channel CarO. Meanwhile, plasmids harboring blaOXA–23 were found after the intervention.ConclusionThe intervention was highly effective in reducing multi-drug resistance of A. baumannii and IRAB outbreaks in the long term. The resistance mechanisms of IRAB may involve genes encoding β-lactamases, efflux pump overexpression, outer membrane porin blockade, and plasmids; in particular, clonal spread of blaOXA–23 was the major cause of outbreaks. Similar interventions may also help reduce bacterial resistance rates and outbreaks in other hospitals.

scholarly journals Occurrence of NDM-1 and VIM-2 Co-Producing Escherichia coli and OprD Alteration in Pseudomonas aeruginosa Isolated from Hospital Environment Samples in Northwestern Tunisia

Diagnostics ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1617
Author(s):  
Raouaa Maaroufi ◽  
Olfa Dziri ◽  
Linda Hadjadj ◽  
Seydina M. Diene ◽  
Jean-Marc Rolain ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Bacterial Resistance ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Hospital Environment ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Disk Diffusion Method

Hospital environments constitute the main reservoir of multidrug-resistant bacteria. In this study we aimed to investigate the presence of Gram-negative bacteria in one Northwestern Tunisian hospital environment, and characterize the genes involved in bacterial resistance. A total of 152 environmental isolates were collected from various surfaces and isolated using MacConkey medium supplemented with cefotaxime or imipenem, with 81 fermenter bacteria (27 Escherichia coli, and 54 Enterobacter spp., including 46 Enterobacter cloacae), and 71 non-fermenting bacteria (69 Pseudomonas spp., including 54 Pseudomonas aeruginosa, and 2 Stenotrophomonas maltophilia) being identified by the MALDI-TOF-MS method. Antibiotic susceptibility testing was performed by disk diffusion method and E-Test was used to determine MICs for imipenem. Several genes implicated in beta-lactams resistance were characterized by PCR and sequencing. Carbapenem resistance was detected among 12 isolates; nine E. coli (blaNDM-1 (n = 8); blaNDM-1 + blaVIM-2 (n = 1)) and three P. aeruginosa were carbapenem-resistant by loss of OprD porin. The whole-genome sequencing of P. aeruginosa 97H was determined using Illumina MiSeq sequencer, typed ST285, and harbored blaOXA-494. Other genes were also detected, notably blaTEM (n = 23), blaCTX-M-1 (n = 10) and blaCTX-M-9 (n = 6). These new epidemiological data imposed new surveillance strategies and strict hygiene rules to decrease the spread of multidrug-resistant bacteria in this area.

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