scholarly journals A Study on High and Low level Drug Resistance Pattern Among Clinical Isolates of Enterococci .

2021 ◽  
Vol 14 (3) ◽  
pp. 1189-1196
Author(s):  
Reena Rajan ◽  
D Karthikeyan
Keyword(s):  
Drug Resistance ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Automated System ◽  
Diffusion Method ◽  
Low Level ◽  
Drug Resistance Pattern ◽  
Resistance To Penicillin ◽  
High Level ◽  
Level Resistance

Introduction: The combined abilities of colonisation and both inherent and acquired resistance have made Enterococci a significant human pathogen. Aims and Objectives: This study was done to determine the Minimum Inhibitory Concentration of various antibiotics against Enterococci and to correlate the phenotypic and genotypic characteristics of Enterococci with low level and high level drug resistance. Materials and Methods: A total of 774 isolates of Enterococci obtained from various clinical samples were subjected to antimicrobial susceptibility testing by Kirby Bauer Disk Diffusion method. The Minimum Inhibitory Concentration of various antibiotics were determined by Vitek 2 automated system, agar dilution and E test. Results: 15 out of 774 isolates showed the presence of vancomycin resistant genes by Multiplex PCR. 10 (90.91 %) isolates out of 11 E. faecalis with van A gene showed high level resistance to Penicillin (16-64 µg/ml). 8 (72.73 %) out of 11 isolates showed high level resistance to Gentamicin (512-1024 µg/ml). 6 (54.55 %) , out of 11 isolates were resistant to β lactams. One isolate of E. faecalis from urine with van B gene showed showed high level resistance to Penicillin (32 µg/ml), Linezolid (≥ 8µg/ml), high level resistance to Gentamicin (1024 µg/ml), Fluoroquinolones (≥ 8µg/ml) and Macrolides (≥ 8µg/ml). Conclusion: Isolates of Enterococci resistant to glycopeptides, penicillin, Betalactams and aminoglycosides have important clinical implications in the treatment for infection.

scholarly journals Antimicrobial Susceptibility Pattern of Salmonella spp. Isolated from Enteric Fever Patients in Nepal

2021 ◽  
Vol 13 (2) ◽  
pp. 388-400
Author(s):  
Anu Maharjan ◽  
Binod Dhungel ◽  
Anup Bastola ◽  
Upendra Thapa Shrestha ◽  
Nabaraj Adhikari ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Minimum Inhibitory Concentration ◽  
Nalidixic Acid ◽  
Antimicrobial Susceptibility ◽  
Enteric Fever ◽  
Inhibitory Concentration ◽  
Diffusion Method ◽  
Susceptibility Pattern ◽  
Salmonella Spp ◽  
Blood Samples

Introduction: Enteric fever, a systemic infection caused by Salmonella enterica Typhi and S. enterica Paratyphi is one of the most common infections in developing countries such as Nepal. Aside from irrational practices of antibiotic use, mutations in chromosomal genes encoding DNA gyrase and Topoisomerase IV and by plasmid mediated quinolone resistant (PMQR) genes are suggested mechanisms for the development of resistance to nalidixic acid and reduced susceptibility to ciprofloxacin. Regardless of high endemicity of enteric fever in Nepal, there is paucity of studies on prevalence and drug-resistance of the pathogen. Therefore, this study aimed to assess the antibiotic susceptibility pattern of Salmonella isolates and determine the minimum inhibitory concentration of ciprofloxacin. Methods: A total of 1298 blood samples were obtained from patients with suspected enteric fever, attending Sukraraj Tropical and Infectious Disease Hospital (STIDH) during March–August, 2019. Blood samples were inoculated immediately into BACTEC culture bottles and further processed for isolation and identification of Salmonella Typhi and S. Paratyphi. Axenic cultures of the isolates were further subjected to antimicrobial susceptibility testing (AST) by using the modified Kirby–Bauer disc diffusion method based on the guidelines by CLSI. The minimum inhibitory concentration (MIC) of ciprofloxacin was determined by agar-dilution method. Results: Out of 1298 blood cultures, 40 (3.1%) were positive for Salmonella spp. among which 29 (72.5%) isolates were S. Typhi and 11 (27.5%) isolates were S. Paratyphi A. In AST, 12.5% (5/40), 15% (6/40) and 20% (8/40) of the Salmonella isolates were susceptible to nalidixic acid, ofloxacin and levofloxacin, respectively, whereas none of the isolates were susceptible to ciprofloxacin. The MIC value for ciprofloxacin ranged from 0.06-16 µg/mL in which, respectively, 5% (2/40) and 52.5% (21/40) of the isolates were susceptible and resistant to ciprofloxacin. None of the isolates showed multidrug-resistance (MDR) in this study. Conclusion: This study showed high prevalence of quinolone-resistant Salmonella spp., while there was marked re-emergence of susceptibilities to traditional first option drugs. Hence, conventional first-line-drugs and third-generation cephalosporins may find potential usage as the empirical drugs for enteric fever. Although our reporting was free of MDR strains, extensive surveillance, augmentation of diagnostic facilities and treatment protocol aided by AST report are recommended for addressing the escalating drug-resistance in the country.

scholarly journals High level resistance to Erythromycin and Tetracycline and dissemination of resistance determinants among clinical enterococci in Kerman-Iran

2021 ◽  
Author(s):  
Nikta Ahmadpoor ◽  
Roya Ahmadrajabi ◽  
Sarvenaz Esfahani ◽  
Zoya Hojabri ◽  
Mohammad Hassan Moshafi ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Tetracycline Resistance ◽  
Resistance Mechanisms ◽  
Resistance Determinants ◽  
High Prevalence ◽  
Genes Encoding ◽  
High Level ◽  
O 31 ◽  
Level Resistance

Objectives: The purpose of this study was to investigate the distribution pattern of genes responsible for erythromycin and tetracycline resistance and their association with resistance phenotype in enterococci isolates. Materials and Methods: Eighty six Enterococcus faecalis and 26 E. faecium isolates were collected from two hospitals in Kerman-Iran. Minimum inhibitory concentration of erythromycin and tetracycline were determined and then, genes encoding resistance to erythromycin; erm (A-C), mef and msr -and tetracycline; tet (M), tet (O), tet (S), tet (K) and tet (L) – were investigated. Results: In all resistant isolates (n= 72, 64%), high level resistance to both tested antibiotics was found. The most prevalent erm gene was erm (B) (77.7%), followed by erm (A) (15.2%) and erm (C) (8.3%). Genes mediating erythromycin efflux, were detected in 70.8 % (mef) and 9.7% (msr) of resistant isolates. Regarding tetracycline, tet (M) was detected at the highest rate (50%), followed by tet (O) (31%) and tet (S) (11%). Export of tetracycline was found in 31% (tet (K)) and 12% (tet (L)) of isolates. Conclusion: High prevalence of high level resistance to both erythromycin and tetracycline was documented. The alteration at ribosomal level, had bigger role in erythromycin and tetracycline resistance than efflux systems. Concurrent resistance mechanisms were more involved in resistance to erythromycin than tetracycline.

Characteristics of drug resistance in HIV-1 CRF55_01B from ART-experienced patients in Guangdong, China

2020 ◽  
Vol 75 (7) ◽  
pp. 1925-1931 ◽  
Author(s):  
Yun Lan ◽  
Ruolei Xin ◽  
Weiping Cai ◽  
Xizi Deng ◽  
Linghua Li ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Drug Susceptibility ◽  
Public Health Issue ◽  
Resistance Mutations ◽  
Acquired Drug Resistance ◽  
Low Level ◽  
High Level ◽  
Hiv 1 ◽  
Level Resistance ◽  
Epidemiological Information

Abstract Background HIV-1 acquired drug resistance (ADR) has become a critical clinical and public health issue. Recently, HIV-1 CRF55_01B has been found more frequently in the MSM population. Objective To investigate the characteristics of HIV-1 drug resistance mutations (DRMs) and the extent of changes in drug susceptibility among ART-experienced CRF55_01B-infected adults of Guangdong. Methods ADR was tested for immediately in CRF55_01B-infected patients with virological failure. Demographic and epidemiological information was collected. DRMs and antiretroviral susceptibility were interpreted using the Stanford University HIV Drug Resistance Database HIVdb program. Results Overall, 162 (4.78%) CRF55_01B isolates were identified from 2013 to 2018. Among DRMs, M184V (43.83%) was the most frequent NRTI DRM, followed by K65R (23.46%), and V179E (98.77%) was the most frequent NNRTI DRM, followed by K103N (47.53%) and Y181C (14.81%). According to the HIVdb program, 79.01% of the CRF55_01B-infected patients carried mutations conferring low-level or higher drug resistance to any of the three classes of ART drugs. Among PI DRMs, only one mutation affording low-level resistance to nelfinavir was found (0.62%). Among NRTI DRMs, a high proportion of high-level resistance to lamivudine (58.64%) and emtricitabine (58.02%) was found. As regards NNRTIs, more than 75% of patients carried efavirenz and nevirapine DRMs. The percentages of high-level resistance were 70.99%, 63.58%, 22.22%, 17.90% and 4.32% for nevirapine, efavirenz, rilpivirine, doravirine and etravirine, respectively. Conclusions High frequencies of DRMs and resistance were observed among CRF55_01B-infected patients failing ART in Guangdong, and interventions may be considered to minimize ecological contributions to ART.

scholarly journals Overexpression of the MtrC-MtrD-MtrE Efflux Pump Due to an mtrR Mutation Is Required for Chromosomally Mediated Penicillin Resistance in Neisseria gonorrhoeae

2002 ◽  
Vol 184 (20) ◽  
pp. 5619-5624 ◽  
Author(s):  
Wendy L. Veal ◽  
Robert A. Nicholas ◽  
William M. Shafer
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Base Pair ◽  
Efflux Pump ◽  
Penicillin Resistance ◽  
Single Base ◽  
Base Pair Deletion ◽  
Resistance To Penicillin ◽  
Single Base Pair ◽  
High Level ◽  
Level Resistance

ABSTRACT The importance of the mtrCDE-encoded efflux pump in conferring chromosomally mediated penicillin resistance on certain strains of Neisseria gonorrhoeae was determined by using genetic derivatives of penicillin-sensitive strain FA19 bearing defined mutations (mtrR, penA, and penB) donated by a clinical isolate (FA6140) expressing high-level resistance to penicillin and antimicrobial hydrophobic agents (HAs). When introduced into strain FA19 by transformation, a single base pair deletion in the mtrR promoter sequence from strain FA6140 was sufficient to provide high-level resistance to HAs (e.g., erythromycin and Triton X-100) but only a twofold increase in resistance to penicillin. When subsequent mutations in penA and porIB were introduced from strain FA6140 into strain WV30 (FA19 mtrR) by transformation, resistance to penicillin increased incrementally up to a MIC of 1.0 μg/ml. Insertional inactivation of the gene (mtrD) encoding the membrane transporter component of the Mtr efflux pump in these transformant strains and in strain FA6140 decreased the MIC of penicillin by 16-fold. Genetic analyses revealed that mtrR mutations, such as the single base pair deletion in its promoter, are needed for phenotypic expression of penicillin and tetracycline resistance afforded by the penB mutation. As penB represents amino acid substitutions within the third loop of the outer membrane PorIB protein that modulate entry of penicillin and tetracycline, the results presented herein suggest that PorIB and the MtrC-MtrD-MtrE efflux pump act synergistically to confer resistance to these antibiotics.

Antimicrobial activities of different parts of two geographically distinct varieties of Jatropha curcas Linn. fruit in Pakistan

2021 ◽  
Vol 50 (2) ◽  
pp. 219-226
Author(s):  
Abdul Haq ◽  
Alam Khan ◽  
Zulfiqar Ali Malik ◽  
Mushtaq Ahmed ◽  
Samiullah Khan ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Minimum Inhibitory Concentration ◽  
Seed Coat ◽  
Jatropha Curcas ◽  
Inhibitory Concentration ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Seed Kernel ◽  
Subtilis Atcc ◽  
Bacillus Subtilis Atcc

Antimicrobial activities of deoiled seed kernel (mechanically pressed), fruit coat and seed coat of Jatropha curcas Linn. collected from two regions (Bannu and Peshawar) of Pakistan were investigated. The antimicrobial activities were carried out against Klebsiella pneumoniae (ATCC 43816), Escherichia coli (ATCC 10536), Staphylococcus aureus (ATCC 6538), Bacillus subtilis (ATCC 6633) and two clinical fungal isolates Aspergillus fumigatus and Candida albicans using agar well diffusion method. The antibacterial activities of Peshawar sample were found to be higher than Bannu, against selected strains. While antifungal activities of both samples were similar. Highest zone of inhibition 31.5 ± 0.7 mm was exhibited by n-hexane extract of deoiled seed kernel of Peshawar sample against Bacillus subtilis (ATCC 6633). The minimum inhibitory concentration of ethanolic extracts of deoiled seed kernel and seed coat of Peshawar sample was 31.25 - 25 mg/ml. Whereas, minimum inhibitory concentration of ethanolic and n-hexane extracts of Bannu sample was 62.5 - 125 mg/ml. The results suggested that antimicrobial potential of J. curcas Linn. varied with geographical distribution. The investigation of different varieties of medicinal plants belonging to the same species will greatly enhance the chances of best pharmaceuticals discovery. Bangladesh J. Bot. 50(2): 219-226, 2021 (June)

scholarly journals O05.4 Does high-level azithromycin resistance emerge from low-level resistance inneisseria gonorrhoeae?

2017 ◽  
Author(s):  
Michelle Cole ◽  
Anthony Underwood ◽  
Kate Templeton ◽  
Jill Shepherd ◽  
Gwenda Hughes ◽  
...  
Keyword(s):  
Low Level ◽  
High Level ◽  
Azithromycin Resistance ◽  
Level Resistance

scholarly journals STRUCTURE CHARACTERIZATION AND EVALUATION POTENTIAL OF ANTIMICROBIAL EXTRACTS FROM PHELLINUS LINTEUS AGAINST SKIN INFECTIOUS PATHOGENS, STAPHYLOCOCCUS EPIDERMIDIS ATCC12228 AND PROPIONIBACTERIUM ACNES DMST14916

2017 ◽  
Vol 9 (12) ◽  
pp. 78
Author(s):  
Surachai Techaoei ◽  
Pattaranut Eakwaropas ◽  
Khemjira Jarmkom ◽  
Warachate Khobjai
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Ethyl Acetate ◽  
Crude Extract ◽  
Staphylococcus Epidermidis ◽  
Inhibitory Concentration ◽  
Propionibacterium Acnes ◽  
Structure Characterization ◽  
Diffusion Method ◽  
Phellinus Linteus ◽  
Chemical Profile

Objective: The objective of this study was to investigate the antimicrobial activity of Phellinus linteus against skin infectious pathogens, Staphylococcus epidermidis ATCC12228 and Propionibacterium acnes DMST 14916.Methods: Fungal fruiting bodies were extracted with 95% ethanol and ethyl acetate, and then, vaporized. The antimicrobial activities were determined by the disc diffusion method against Propionibacterium acnes DMST 14916 and Staphylococcus epidermidis ATCC12228 skin infectious pathogens. A minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) for those crude extracts were determined. Finally, the chemical profile of crude extract was determined by using thin layer chromatography and GC-MS.Results: The result demonstrated that the ethanolic extraction had more active fractions with an MIC of 0.5 mg/ml against the growth of Propionibacterium acnes DMST 14916 and Staphylococcus epidermidis ATCC12228 and also showed a minimum inhibitory concentration (MBC) at a concentration of 1.0 mg/ml, while ethyl acetate-based solvents failed to develop on TLC according to Retention factor (Rf) values of 0.71-0.76. The GC-MS was applied to investigate the chemical profile of crude extract of Phellinus linteus, revealing a component of hexadecanoic acid and 9, 12-octadecadienoic acid.Conclusion: Phellinus linteus fruiting body extracts have great potential as antimicrobial compounds against Propionibacterium acnes DMST 14916 and Staphylococcus epidermidis ATCC12228. Thus, they can be used in the treatment of infectious diseases caused by bacterial pathogens. 

scholarly journals Antibiogram signatures of non-cholera causing Vibrio species recovered from environmental niches in Eastern Cape, South Africa.

2021 ◽  
Author(s):  
Oluwakemi Victoria Ayodele ◽  
Anthony Ifeanyi Okoh
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Nalidixic Acid ◽  
Vibrio Parahaemolyticus ◽  
Inhibitory Concentration ◽  
Vibrio Vulnificus ◽  
Diffusion Method ◽  
Morbidity Rate ◽  
Antibiotic Resistant ◽  
Mortality And Morbidity ◽  
Vibrio Fluvialis

Abstract Background: The use of antibiotics globally has helped reduce mortality and morbidity rate due to its ability to effectively treat bacterial infections in both humans and animals. However, the menace of antimicrobial resistance has become a challenge to public health due to its increased mortality and morbidity rate. This study determined the antibiogram pattern of non-cholera causing Vibrio species against a panel of 11 antibiotics that are wildly used for treatment. Multiple antibiotic resistance phenotype, multiple antibiotic resistant indices and minimum inhibitory concentration (MIC) of test antibiotics were also determined.Results: Polymerase chain reaction (PCR) was used to confirm 100 isolates of Vibrio parahaemolyticus, 82 and 46 isolates of Vibrio vulnificus and Vibrio fluvialis respectively, collected from the culture collections of the Applied and Environmental Microbiology Research Group (AEMREG), University of Fort Hare. Thereafter, disc diffusion method was used to determine the antibiogram pattern of target non-cholera causing Vibrio species against a panel of 11 antibiotics that are of clinical importance. The highest rate of Vibrio parahaemolyticus resistance was observed against tetracycline (22 %) and nalidixic acid (16 %). Vibrio fluvialis also displayed highest rate of resistance against tetracycline (28 %) and nalidixic acid (28 %), while Vibrio vulnificus isolates exhibited highest rate resistance against imipenem (40 %) and tetracycline (22 %). A total of 38 MARP patterns were observed and the MAR indices ranged between 0.3 and 0.8. Against the resistant Vibrio parahaemolyticus and Vibrio fluvialis isolates, minimum inhibitory concentration ranged from 16 µg/ml to 2048 µg/ml for both tetracycline and nalidixic acid, while against Vibrio vulnificus isolates, minimum inhibitory concentration ranged from 8 µg/ml to 256 µg/ml for both imipenem and nalidixic acid. Conclusions: Results obtained from this study is an indication that antibiotic resistant bacteria that could pose as threat to health of humans and animals are present in the environment.

scholarly journals Mono-/Bis-Alkenoic Acid Derivatives From an Endophytic Fungus Scopulariopsis candelabrum and Their Antifungal Activity

2022 ◽  
Vol 9 ◽  
Author(s):  
Jun Tang ◽  
Xueshuang Huang ◽  
Ming-Hang Cao ◽  
Zhiyan Wang ◽  
Zhiyin Yu ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
High Resolution Mass Spectrometry ◽  
2D Nmr ◽  
Positive Control ◽  
Diffusion Method ◽  
Exserohilum Turcicum ◽  
Chemical Structures ◽  
Alkenoic Acid

During a screening for antifungal secondary metabolites, six new mono-/bis-alkenoic acid derivatives (2–7) and one known alkenoic acid derivative (1) were isolated from an endophytic fungi Scopulariopsis candelabrum. Their chemical structures were identified by 1H-NMR, 13C-NMR, 2D NMR, and high-resolution mass spectrometry, as well as comparisons with previously reported literatures. Among them, fusariumesters C‒F (2–5) are bis-alkenoic acid derivatives dimerized by an ester bond, while acetylfusaridioic acid A (6) and fusaridioic acid D (7) are alkenoic acid monomers. All the isolates were submitted to an antifungal assay against Candida albicans and the corn pathogen Exserohilum turcicum using the filter paper agar diffusion method. As a result, only compound 1 decorating with β-lactone ring turned out to be active against these two tested fungi. The broth microdilution assay against Candida albicans showed the minimum inhibitory concentration (MIC) value of 1 to be 20 μg/ml, while the minimum inhibitory concentration value of the positive control (naystatin) was 10 μg/ml. And the half maximal inhibitory concentration (IC50) value (21.23 μg/ml) of 1 against Exserohilum turcicum was determined by analyzing its inhibition effect on the mycelial growth, using cycloheximide (IC50 = 46.70 μg/ml) as the positive control.

Sign in / Sign up

Export Citation Format

Share Document