Prevalence, Antibiogram and Molecular Characterization of Comunity-Acquired Methicillin-Resistant Staphylococcus Aureus in AWKA, Anambra Nigeria

Objectives:This study evaluated the prevalence, antibiogram and molecular features of CA-MRSA in Awka, Nigeria.Methods:Confirmation of MRSA was done by testing resistance to oxacillin (1µg), cloxacillin (5µg) and cefoxitin(30µg) on sterile Mueller Hinton agar supplemented with 4% sodium chloride. The MRSA strains were subjected to antimicrobial susceptibility testing using Kirby-Bauer disc diffusion method. Minimum inhibitory concentration was determined using agar dilution method. Penicillin binding protein 2a was detected through rapid latex agglutination assay while mecA gene was detected by polymerase chain reaction. A total of 142S. aureusisolates were obtained from 261 samples sourced from Staff, students and fomites of the Faculty of Pharmaceutical SciencesResult:The overall prevalence of MRSA was 22.6%. The carriage rate was higher in females (56.5%) than male (43.5%) and was highest in individuals of 20-30 years of age (57.65%). The MIC of the oxacillin sodium salt ranged from 4-32 μg/ml. The multi-antibiotic resistance indices show that 53.4% had Multiple Antibiotic Resistance Indexing (MARI) higher than 0.2. Penicillin binding protein 2a was detected in 8.4% of MRSA isolates, all from nasal carriage while mecA gene was detected in 5 of isolates.Conclusion:This study showed a very high prevalence of MRSA carriage among studied subjects.

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Department of Microbiology, Bangladesh Agricultural University, Mymensingh

Bangladesh Journal of Medical Microbiology ◽

10.3329/bjmm.v2i2.28839 ◽

2016 ◽

Vol 2 (2) ◽

pp. 3-6

Author(s):

Nahida Akther Zahan ◽

Md. Akram Hossain ◽

AKM Shamsuzzaman ◽

AKM Musa ◽

Md. Chand Mahamud ◽

...

Keyword(s):

Clinical Laboratory ◽

Methicillin Resistance ◽

Meca Gene ◽

Toxin Production ◽

Latex Agglutination ◽

Diffusion Method ◽

National Committee ◽

Dilution Method ◽

Agar Dilution Method ◽

Disk Diffusion Method

The study was done to detect different exotoxins among the strains of Staphylococcus aureus isolated in the department of Microbiology, Mymensingh Medical College in collaboration with the Department of Medicine under the Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh between the periods from July, 2006 to June, 2007. A total of 40 S. aureus isolates investigated in this study were identified by standard microbiological techniques. Antimicrobial susceptibility of the isolates to Oxacillin was carried out by disk diffusion method as per recommendation of the National Committee for Clinical Laboratory Standards. Any isolate showing resistance to Oxacillin was tested again by agar dilution method to determine minimum inhibitory concentration (MIC) of Methicillin. All strains were also tested for mecA gene by Polymerase Chain Reaction (PCR) for confirmation of Methicillin resistance. Enterotoxin (A-D) and Toxic Shock Syndrome Toxin-1 (TSST-1) were detected by Reverse Passive Latex Agglutination (RPLA) test. Out of 40 S. aureus isolates, 7 (17.5%) Methicillin Resistant S. aureus (MRSA), 1 (2.5%) Methicillin Sensitive S. aureus (MSSA) produced Staphylococcal Enterotoxin A (SE-A) and 1 MRSA isolate was positive for TSST-1. In case of combined toxin production among the S. aureus isolates, 2 (5%) MSSA were found to produce SE-A and SE-B, 2 (5%) MSSA produced SE-C and SE-D, and 1 (2.5%) MRSA, 1 (2.5%) MSSA produced SE-C and TSST-1.Bangladesh J Med Microbiol 2008; 02 (02): 3-6

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Microwave-Hydrothermal Rapid Synthesis of Cellulose/Ag Nanocomposites and Their Antibacterial Activity

Nanomaterials ◽

10.3390/nano8120978 ◽

2018 ◽

Vol 8 (12) ◽

pp. 978 ◽

Cited By ~ 10

Author(s):

Lian-Hua Fu ◽

Qing-Long Gao ◽

Chao Qi ◽

Ming-Guo Ma ◽

Jun-Feng Li

Keyword(s):

Antibacterial Activity ◽

Antimicrobial Properties ◽

Silver Ions ◽

Heating Time ◽

Diffusion Method ◽

Dilution Method ◽

Agar Dilution Method ◽

Human Beings ◽

Microwave Hydrothermal ◽

Wide Range

Silver-based antimicrobial nanomaterials are considered as the most promising antibacterial agents owing to their outstanding antimicrobial efficacy and their relatively low toxicity to human beings. In this work, we report on a facile and environment-friendly microwave-hydrothermal method to prepare cellulose/Ag nanocomposites using hemicellulose as the reductant. The influences of the microwave-hydrothermal heating time and temperature, as well as the hemicellulose concentration on the formation of cellulose nanocomposites, were investigated in detail. Experimental results indicated that the hemicellulose was an effective reductant for silver ions, with higher temperature and longer heating time favoring the formation of silver with higher crystallinity and mass content in the nanocomposites. Moreover, the antimicrobial properties of the as-prepared cellulose/Ag nanocomposites were explored using Gram-positive S. aureus ATCC 6538 and Gram-negative E. coli HB 101 by both disc diffusion method and agar dilution method, and the nanocomposites showed excellent antibacterial activity. These results demonstrate that the as-prepared cellulose/Ag nanocomposites, as a kind of antibacterial material, are promising for applications in a wide range of biomedical fields.

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Crystal structures of the transpeptidase domain of the Mycobacterium tuberculosis penicillin-binding protein PonA1 reveal potential mechanisms of antibiotic resistance

FEBS Journal ◽

10.1111/febs.13738 ◽

2016 ◽

Vol 283 (12) ◽

pp. 2206-2218 ◽

Cited By ~ 13

Author(s):

Ekaterina V. Filippova ◽

Karen J. Kieser ◽

Chi-Hao Luan ◽

Zdzislaw Wawrzak ◽

Olga Kiryukhina ◽

...

Keyword(s):

Antibiotic Resistance ◽

Mycobacterium Tuberculosis ◽

Crystal Structures ◽

Binding Protein ◽

Penicillin Binding Protein

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Evaluation of antibiotic resistance pattern and mecA gene frequency in methicillin-resistant Staphylococcus aureus strains collected from clinical specimens in Marand hospital and treatment centers, Iran

Tabari Biomedical Student Research Journal ◽

10.18502/tbsrj.v2i4.5469 ◽

2021 ◽

Author(s):

Abolfazl Jafari-Sales ◽

Zahra Sadeghi Deylamdeh ◽

Afsoon Shariat

Keyword(s):

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Methicillin Resistant Staphylococcus Aureus ◽

Meca Gene ◽

Disk Diffusion ◽

Diffusion Method ◽

Disk Diffusion Method ◽

Methicillin Resistant ◽

Medical Centers ◽

Wide Range

Introduction: Staphylococcus aureus causes a wide range of infections and as a multivalent pathogen is one of the causative agents of nosocomial and community infections. Therefore, the aim of this study was to identify and determine the pattern of antibiotic resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolates from patients in hospitals and medical centers in Marand city and also to evaluate the presence of mecA gene. Materials and Methods: In this cross-sectional descriptive study, 385 samples of S. aureus were collected from different clinical samples of patients in hospitals and medical centers of Marand city. S. aureus was identified using standard biochemical methods. Methicillin resistance was determined by disk diffusion method in the presence of oxacillin and cefoxitin. The pattern of antibiotic resistance of the strains was determined by disk diffusion method and according to CLSI recommendation and also PCR method was used to evaluate the frequency of MecA gene. Results: In the present study, out of 385 samples of S. aureus, 215 (55.84%) samples were methicillin resistant. PCR results for mecA gene showed that 110 samples had mecA gene. The highest antibiotic resistance was observed against penicillin (100%) and erythromycin (83.63%). Most MRSA were isolated from urine and wound samples. Conclusion: The results of this study indicate the prevalence of methicillin-resistant species and also the increase in antibiotic resistance of MRSA to various antibiotics. Therefore, in order to prevent increased resistance to other antibiotics, it is recommended to avoid inappropriate use of antibiotics.

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Comparison of methods for the determination of antimicrobial resistance in Campylobacter spp. human and the food chain isolates

Veterinární Medicína ◽

10.17221/2030-vetmed ◽

2008 ◽

Vol 52 (No. 4) ◽

pp. 169-174

Author(s):

M. Holasova ◽

R. Karpiskova ◽

S. Karpiskova ◽

V. Babak ◽

J. Schlegelova

Keyword(s):

Nalidixic Acid ◽

Antimicrobial Agents ◽

Disk Diffusion ◽

Diffusion Method ◽

Dilution Method ◽

Agar Dilution Method ◽

Disk Diffusion Method ◽

Microdilution Method ◽

Study Results ◽

Agar Dilution

With a microdilution method, using the commercial diagnostic test Sensititre Susceptibility Plates for Campylobacter MIC (Trek Diagnostic Systems, Cleveland, OH, USA), disk diffusion and agar dilution method, resistance to six antimicrobial agents were examined in a reference strain Campylobacter jejuni ATCC 33560 and 73 thermo-tolerant isolates of Campylobacter spp. For the microdilution method and all tested antimicrobial agents, our determined values of microbiological breakpoints of resistant strains were suggested as the minimum inhibitory concentration (MICR) for ciprofloxacin ≥ 0.5, erythromycin ≥ 4, gentamicin ≥ 4, nalidixic acid ≥ 32 and tetracycline ≥ 4 μg/ml. On the basis of our study results, strains resistant to clindamycin were MICR ≥ 2 μg/ml for the dilution methods and a zone diameter R Ã¢ÂÂ¤ 16 mm for the disk diffusion method. Comparison of the results of the resistance examination, a microdilution method and disk diffusion method with the reference agar dilution method, showed that all compared methods yielded identical results with the exception of the resistance determination in erythromycin and nalidixic acid. The errors were mostly the result of the interpretation criteria for MICR of agar dilution method and different conditions of cultivation used. However, the compared methods, provide results comparable with the reference method having greater convenience of measurement.

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Plasmid mediated colistin resistant mcr-1 and co-existence of OXA-48 among Escherichia coli from clinical and poultry isolates: first report from Nepal

Gut Pathogens ◽

10.1186/s13099-020-00382-5 ◽

2020 ◽

Vol 12 (1) ◽

Cited By ~ 1

Author(s):

Bijaya Muktan ◽

Upendra Thapa Shrestha ◽

Binod Dhungel ◽

Bagish Chandra Mishra ◽

Nabaraj Shrestha ◽

...

Keyword(s):

Escherichia Coli ◽

Resistance Gene ◽

Diffusion Method ◽

Dilution Method ◽

Agar Dilution Method ◽

Colistin Resistance ◽

Clinical Specimens ◽

E Coli ◽

Resistant Genes ◽

Rectal Swabs

Abstract Background Plasmid-mediated resistance to the last-resort drugs: carbapenems and colistin is an emerging public health threat. The studies on the prevalence and co-expression of resistant genes among livestock and human pathogens are rare in Nepal. This is the first study in Nepal exploring the prevalence and co-existence of colistin resistance gene, mcr-1 along with carbapenemase resistance gene, OXA-48 in Escherichia coli isolated from poultry and clinical specimens. Methods A total of 240 rectal swabs from chickens of five different poultry farms of Kathmandu valley and 705 mid-stream urine samples from human subjects attending Kantipur Hospital, Kathmandu were collected between August, 2018 and March, 2019. Rectal swabs and urine specimens were cultured. E. coli isolated from the specimens were screened for antimicrobial susceptibility testing (AST) using disk diffusion method’. Minimum inhibitory concentration (MIC) of colistin was determined by agar dilution method using 0.5 µg/ml to 32 µg/ml. The E. coli isolates were first screened for mcr-1 followed by screening for OXA-48 genes using conventional Polymerase chain reaction (PCR). Results Of the total samples analyzed, E. coli was isolated from 31.7% (76/240) of poultry and 7.9% (56/705) of clinical specimens. In AST, 80% (61/76) of E. coli from poultry and 79% (44/56) from clinical specimens were MDR. The phenotypic prevalence of colistin resistance in poultry specimens were 31.6% (24/76) and clinical specimens were 21.4% (12/56). In PCR assay, 27.6% (21/76) of poultry and 19.6% (11/56) of clinical isolates had colistin resistant mcr-1 gene. MICs value of E. coli isolates ranged from 4 to 32 (µg/ml) in both clinical and poultry isolates. Prevalence of co-existing carbapenem resistance gene, OXA-48, among colistin resistant mcr-1 positive isolates was 38% (8/21) in poultry specimens and 18.2% (2/11) in clinical specimens. Conclusions The high prevalence of colistin and carbapenem resistant genes, and their co-existence in plasmid DNA of E. coli isolates in this study suggests the possible spread to other animal, human and environmental pathogens. Molecular methods in addition to the conventional diagnostics in laboratories can help in early diagnosis, effective management and control of their potential transmission.

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Increasing antibiotic resistance in clinical isolates of Aeromonas strains in Taiwan.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.40.5.1260 ◽

1996 ◽

Vol 40 (5) ◽

pp. 1260-1262 ◽

Cited By ~ 71

Author(s):

W C Ko ◽

K W Yu ◽

C Y Liu ◽

C T Huang ◽

H S Leu ◽

...

Keyword(s):

United States ◽

Antibiotic Resistance ◽

The United States ◽

Clinical Isolates ◽

Dilution Method ◽

Agar Dilution Method ◽

Extended Spectrum ◽

Agar Dilution

A total of 234 clinical isolates of Aeromonas, primarily A. hydrophila, were collected for the present study. Most were isolates from blood. By the agar dilution method, more than 90% of the Aeromonas strains were found to be susceptible to moxalactam, ceftazidime, cefepime, aztreonam, imipenem, amikacin, and fluoroquinolones, but they were more resistant to tetracycline, trimethoprim-sulfamethoxazole, some extended-spectrum cephalosporins, and aminoglycosides than strains from the United States and Australia.

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Inaccuracy of the Disk Diffusion Method Compared with the Agar Dilution Method for Susceptibility Testing of Campylobacter spp.

Journal of Clinical Microbiology ◽

10.1128/jcm.01090-11 ◽

2011 ◽

Vol 50 (1) ◽

pp. 52-56 ◽

Cited By ~ 31

Author(s):

Mirva Lehtopolku ◽

Pirkko Kotilainen ◽

Pauli Puukka ◽

Ulla-Maija Nakari ◽

Anja Siitonen ◽

...

Keyword(s):

Susceptibility Testing ◽

Disk Diffusion ◽

Diffusion Method ◽

Dilution Method ◽

Agar Dilution Method ◽

Disk Diffusion Method ◽

Agar Dilution ◽

Campylobacter Spp

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Current Fluoroquinolone Susceptibility Criteria for Salmonella Needs Re-evaluation

Kathmandu University Medical Journal ◽

10.3126/kumj.v10i1.6909 ◽

2012 ◽

Vol 10 (1) ◽

pp. 66-71 ◽

Cited By ~ 1

Author(s):

D Acharya ◽

S Malla ◽

DR Bhatta ◽

N Adhikari ◽

SP Dumre

Keyword(s):

Nalidixic Acid ◽

Enteric Fever ◽

Susceptibility Testing ◽

Break Point ◽

Resistance Rate ◽

Diffusion Method ◽

Dilution Method ◽

Agar Dilution Method ◽

Disc Diffusion ◽

Zone Diameter

Background Disc diffusion technique is the routine susceptibility testing procedure for isolates of enteric fever, the most common clinical diagnosis among febrile patients in Nepal. Objective To evaluated the current fluoroquinolones (FQs) susceptibility criteria and nalidixic acid screening test in Salmonella enterica serovar Typhi and Paratyphi A. Methods S. Typhi and Paratyphi A strains isolated from 443 suspected enteric fever patients visiting National Public Health Laboratory (NPHL) during April through October 2008 were analyzed. All isolates were confirmed by standard microbiological procedures including serotyping. Antibiotic susceptibility testing was performed by using Kirby Bauer disc diffusion method and Clinical and Laboratory Standards Institute (CLSI) approved interpretive criteria. Agar dilution method was used to determine Minimum Inhibitory Concentration (MIC) of ciprofloxacin, ofloxacin and nalidixic acid. Result Out of 41 Salmonella isolates, 80.49% were nalidixic acid resistant, with S. Paratyphi A showing higher resistance rate (88.23%) compared to S. Typhi (75%). The difference in both MIC and zone diameter in nalidixic acid susceptible and nalidixic acid resistant isolates was found to be significant (P < 0.001) and decreased susceptibility to FQs was strongly correlated (sensitivity and specificity of 100%) with resistance to nalidixic acid. Regression analysis of MIC against zone diameter based on the current CLSI recommended guidelines suggests that accommodation of current susceptible and resistant MIC requires increase in the zone diameter of ciprofloxacin and ofloxacin. Conclusion Before using these drugs for management of enteric fever, appropriate identification of Salmonella isolates with reduced susceptibility to FQs is essential to limit the possible treatment failure and development of highly resistant strains. The current FQs susceptibility break point criteria for Salmonella need re-evaluation. KATHMANDU UNIVERSITY MEDICAL JOURNAL VOL.10 | NO. 1 | ISSUE 37 | JAN - MAR 2012 | 24-29DOI: http://dx.doi.org/10.3126/kumj.v10i1.6909

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Potential spread of multidrug-resistant coagulase-negative staphylococci through healthcare waste

The Journal of Infection in Developing Countries ◽

10.3855/jidc.4563 ◽

2015 ◽

Vol 9 (01) ◽

pp. 029-034 ◽

Cited By ~ 2

Author(s):

Thiago César Nascimento ◽

Vânia Lúcia Da Silva ◽

Alessandra Barbosa Ferreira-Machado ◽

Cláudio Galuppo Diniz

Keyword(s):

Meca Gene ◽

Multidrug Resistant ◽

Resistant Bacteria ◽

Dilution Method ◽

Agar Dilution Method ◽

Coagulase Negative Staphylococcus ◽

Coagulase Negative Staphylococci ◽

Healthcare Waste ◽

Sanitary Landfills ◽

Rdna Sequencing

Introduction: Healthcare waste (HCW) might potentially harbor infective viable microorganisms in sanitary landfills. We investigated the antimicrobial susceptibility patterns and the occurrence of the mecA gene in coagulase-negative Staphylococcus strains (CoNS) recovered from the leachate of the HCW in an untreated sanitary landfill. Methodology: Bacterial identification was performed by physiological and molecular approaches, and minimum inhibitory concentrations (MICs) of antimicrobial drugs were determined by the agar dilution method according to CLSI guidelines. All oxacillin-resistant bacteria were screened for the mecA gene. Results: Out of 73 CoNS, seven different species were identified by 16S rDNA sequencing: Staphylococcus felis (64.4%; n = 47), Staphylococcus sciuri (26.0%; n = 19), Staphylococcus epidermidis (2.7%; n = 2), Staphylococcus warneri (2.7%; n = 2), Staphylococcus lentus (1.4%; n = 1), Staphylococcus saprophyticus (1.4%; n = 1), and Staphylococcus haemolyticus (1.4%; n = 1). Penicillin was the least effective antimicrobial (60.3% of resistance; n = 44) followed by erythromycin (39.8%; n = 29), azithromycin (28.8%; n = 21), and oxacillin (16.5%; n = 12). The most effective drug was vancomycin, for which no resistance was observed, followed by gentamicin and levofloxacin, for which only intermediate resistance was observed (22%, n = 16 and 1.4%, n = 1, respectively). Among the oxacillin-resistant strains, the mecA gene was detected in two isolates. Conclusions: Considering the high antimicrobial resistance observed, our results raise concerns about the survival of putative bacterial pathogens carrying important resistance markers in HCW and their environmental spread through untreated residues discharged in sanitary landfills.

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