scholarly journals In vitro antibiotic susceptibility and biofilm production of Staphylococcus aureus isolates recovered from bovine intramammary infections that persisted or not following extended therapies with cephapirin, pirlimycin or ceftiofur

2017 ◽  
Vol 48 (1) ◽  
Author(s):  
Céline Ster ◽  
Valérie Lebeau ◽  
Julia Leclerc ◽  
Alexandre Fugère ◽  
Koui A. Veh ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Susceptibility ◽  
Intramammary Infections ◽  
Biofilm Production

scholarly journals IDENTIFICATION AND DETECTION OF BIOFILM PRODUCING STAPHYLOCOCCUS AUREUS AND ITS ANTIBIOGRAM ACTIVITIES

2021 ◽  
pp. 150-156
Author(s):  
SAPANA SHARMA ◽  
UPASHANA BHANDARI ◽  
YOGESH OLI ◽  
GANESH BHANDARI ◽  
SUNITA BISTA ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Disk Diffusion ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Methicillin Resistant ◽  
Clinical Specimens ◽  
Biofilm Production ◽  
Diffusion Technique ◽  
Almost All

Objectives: The main aim of this work is to determine the antibiogram profile of biofilm-producing Staphylococcus aureus from various clinical specimens of the patients. Methods: Various bacterial cultures of non-repeated clinical specimens from a total of 3388 patients were determined using standard microbiological and biochemical methods. Results: Out of 3388 only 604 (17.02%) displayed growth positive. A total of 65 (51.58%) S. aureus isolates were recovered, 25 (38.46%) were identified as methicillin-resistant S. aureus (MRSA) by Cefoxitin (30 μg) disk diffusion technique, of which majority were from pus/wound swab 22 (37.29%). The antibiogram of the isolates was analyzed by Kirby-Bauer disk diffusion technique analyzing Linezolid to be the most effective drug with susceptibility of 100% to both MRSA and methicillin-sensitive S. aureus, followed by vancomycin, tigecycline, and tetracycline. In vitro biofilm production by tissue culture plate (TCP) and Congo red agar method detected 52 (80%) and 25 (38.46%) as biofilm producers, respectively. TCP identified 2 (3.07%), 7 (10.76%), and 44 (67.69%) as strongly, moderately, and weakly adherent. About 30.7% of MRSA obtained were positive biofilm producers. The minimum inhibitory concentration value of Oxacillin for S. aureus by agar dilution method ranged from 0.025 μg/mL to 128 μg/mL. Conclusion: This study shows that biofilm production was more in methicillin-resistant strains and displayed a high degree of resistance to almost all groups of antibiotics.

scholarly journals Impact of sarA on Antibiotic Susceptibility of Staphylococcus aureus in a Catheter-Associated In Vitro Model of Biofilm Formation

2009 ◽  
Vol 53 (6) ◽  
pp. 2475-2482 ◽  
Author(s):  
Elizabeth C. Weiss ◽  
Horace J. Spencer ◽  
Sonja J. Daily ◽  
Brian D. Weiss ◽  
Mark S. Smeltzer
Keyword(s):  
Staphylococcus Aureus ◽  
Clinical Isolate ◽  
Antimicrobial Susceptibility ◽  
Antibiotic Susceptibility ◽  
Biofilm Formation ◽  
In Vitro Model ◽  
Susceptibility Testing ◽  
Specific Context ◽  
Vitro Model

ABSTRACT Mutation of the staphylococcal accessory regulator (sarA) in Staphylococcus aureus limits but does not abolish the capacity of the organism to form a biofilm. As a first step toward determining whether this limitation is therapeutically relevant, we carried out in vitro studies comparing the relative susceptibility of an S. aureus clinical isolate (UAMS-1) and its isogenic sarA mutant (UAMS-929) in the specific context of a catheter-associated biofilm. The antibiotics tested were daptomycin, linezolid, and vancomycin, all of which were evaluated by using concentrations based on the MIC defined as the breakpoint for a susceptible strain of S. aureus (≤1.0, ≤2.0, and ≤4.0 μg/ml for daptomycin, vancomycin, and linezolid, respectively). Mutation of sarA had no significant impact on the MIC of UAMS-1 for any of the targeted antibiotics, as defined by Etest antimicrobial susceptibility testing. However, mutation of sarA did result in a significant increase in antimicrobial susceptibility to all targeted antibiotics when they were tested in the specific context of a biofilm. Additionally, whether susceptibility was assessed by using UAMS-1 or its sarA mutant, daptomycin was found to be more effective against established S. aureus biofilms than either linezolid or vancomycin.

scholarly journals Genetic traceability of Staphylococcus aureus strains isolated from primiparous dairy cows mastitis, humans and environment in the Northeast region of Brazil

2021 ◽  
Vol 51 (4) ◽  
Author(s):  
Amanda Thaís Ferreira Silva ◽  
José Givanildo da Silva ◽  
Breno Bezerra Aragão ◽  
Núbia Michelle Vieira da Silva ◽  
Priscylla Carvalho Vasconcelos ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Cows ◽  
Dairy Herds ◽  
Beta Lactam ◽  
Beta Lactams ◽  
High Genetic Diversity ◽  
Northeast Region ◽  
Intramammary Infections ◽  
D Value

ABSTRACT: This research aimed to investigate the genotypic relatedness of 18 Staphylococcus aureus strains isolated from intramammary infections in primiparous cows and extramammary sites on five dairy herds by rep-PCR using RW3A primers, and by PFGE using the endonuclease SmaI. The isolates were also evaluated in vitro for the susceptibility against beta-lactam antimicrobials drugs (penicillin and oxacillin), considering that beta-lactams are frequently used for treating staphylococcal intrammamary infections. The rep-PCR typing was highly discriminatory (D value= 0.9804) and a total of 15 patterns were detected. The PFGE method was also highly discriminatory (D value= 0.9667) and a total of 13 patterns were observed. A total of 15 out of 18 (83%) isolates were resistant to penicillin and one out of 18 (6%) to oxacillin. In conclusion, these findings confirmed the occurrence of a high genetic diversity of S. aureus strains at the herds and the presence of clonally-related strains only at the same herd, emphasizing a variety of genotypic profiles among the isolates.

scholarly journals The Prevalence and the Resistance Profile of Methicillin-Resistant Staphylococcus aureus Colonized in the Nostrils of Cancer Patients in Namazi Teaching Hospital, Shiraz, Iran, 2011-12

2015 ◽  
Vol 4 (1) ◽  
pp. 21-25
Author(s):  
Mohammad Reza Kandehkar Ghahraman ◽  
Razyeh Hassanzadeh ◽  
Mohammad Motamedifar ◽  
Abdolsamad Ashrafzadeh ◽  
Zahra Hashemizadeh
Keyword(s):  
Staphylococcus Aureus ◽  
Cancer Patients ◽  
Antibiotic Susceptibility ◽  
Resistance Pattern ◽  
Susceptibility Pattern ◽  
In Vitro Susceptibility ◽  
Disk Diffusion Test ◽  
Vast Number ◽  
Methicillin Resistant

Background: Methicillin-resistant (MRSA) Staphylococcus aureus (S. aureus) are responsible for a vast number of nosocomial infections especially in immunocompromised subjects such as cancer patients. The presence of comorbidities including malignancies has been associated, with S. aureus bacteremia mortality. Thus, the detection of MRSA in this patients and the antibiotic susceptibility pattern of the isolates eases the selection of first-line medications and the prevention from further complications in cancer patients. The aim of this study was to determine the prevalence of MRSA infection and antibiotic susceptibility patterns of the isolates in pre and post-chemotherapy course in cancer patients.Materials and Methods: From May 2011 to July 2012, 200 nostril samples of cancerous patients were obtained and cultured on blood agar plates. After isolation and confirmation of S. aureus, antibiotic resistance pattern of the isolates was determined pre-chemotherapy and after the chemotherapy against vancomycin, tigecycline, linezolid, chloramphenicol, and oxacillin using disk diffusion test following CLSI guidelines. Chi-square test was used for data analysis.Results: Among a total number of 200 various cancer patients (64.5% females), 42 (21%) cases were positive for S. aureus and 7 (3.5 %) were MRSA carriers. Mean ages of MSSA and MRSA infected patients were 50.97±15.94 and 53.57±18.28 years old, respectively. In vitro susceptibility pattern of the MRSA and MSSA isolates to the 4 tested agents did not differed significantly after the chemotherapy in contrast with pre-chemotherapy state.Conclusions: This study showed that chemotherapy does not change the susceptibility pattern of MRSA species to antibiotics of choice in cancer patients. However, the importance of controlling methicillin resistant staphylococcal infections in critical cases, specifically cancer cases, necessitates the early detection, further investigations on more effective medications.

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