scholarly journals Microbiology quality, detection of enterotoxin genes and antimicrobial resistance of Staphylococcus aureus isolated from milk and Coalho cheese

2018 ◽  
Vol 39 (5) ◽  
pp. 1957 ◽  
Author(s):  
Cecília Teresa Muniz Pereira ◽  
Diêgo Sávio Vasconcelos de Oliveira ◽  
Vanessa Solano Veloso ◽  
Sabina Dos Santos Paulino Silva ◽  
Leidiane Sousa Santos ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
Disk Diffusion ◽  
Foodborne Diseases ◽  
Biochemical Tests ◽  
Disk Diffusion Test ◽  
Resistance Phenotype ◽  
Inducible Resistance ◽  
Enterotoxin Genes

This study evaluated the microbiological quality of milk and Coalho cheese, the prevalence of enterotoxin genes, antimicrobial resistance and determined an inducible MLSB resistance phenotype by the D-test in strains of Staphylococcus aureus isolated from these products. Seventy samples of milk and Coalho cheese were analyzed. S. aureus strains were identified by biochemical tests. The presence of se genes (sea-see) was tested by polymerase chain reaction. The antimicrobial sensitivity of S. aureus strains was evaluated for 13 antimicrobial drugs using the disk diffusion technique and the double-disk diffusion test (D-test) was performed to determine inducible resistance to lincosamide phenotype. The amount of toxin sufficient to cause foodborne diseases is generally observed when Staphylococcus populations exceed 105 CFU mL-1 g-1. In this study, none of the milk samples analyzed showed these counts; however, 73.3% (22/30) of Coalho cheese samples exceeded this value. A total of 109 isolates were identified as S. aureus. The presence of enterotoxin genes was detected in 25.7% of these isolates and amplified only for the sec gene. Most of the isolates (78.5%) were resistant to one or more antimicrobial agents. The D test showed that 25.0% of erythromycin-resistant isolates had the constitutive resistance phenotype, and 3.8% had the inducible resistance phenotype to clindamycin. These results indicate that these dairy products represent a health risk since these bacteria can cause foodborne diseases or may be a possible route for the transfer of antimicrobial resistance to humans.

scholarly journals Epidemiology and antibiotic succeptibility profile of methicillin sensitive Staphylococcus aureus among livestock and pet animals

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Muhammad Aamir Naseer ◽  
Amjad Islam Aqib ◽  
Muhammad Shoaib ◽  
Iqra Muzammil ◽  
Zeeshan Ahmad Bhutta ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Disk Diffusion ◽  
Diffusion Test ◽  
Disk Diffusion Test ◽  
Zoonotic Pathogen ◽  
Caprine Milk ◽  
Microbiological Examination ◽  
Amoxicillin Clavulanic Acid

Staphylococcus aureus is an important zoonotic pathogen that is responsible for a variety of infectious diseases in humans and animals. The present study was designed to check the prevalence and antimicrobial resistance of MSSA from three different animal origins (bovine, caprine and pet). A total of n= 450 samples (150 each source) were collected from bovine, caprine and pets. Collected samples were subjected to S. aurues identification by microbiological examination and confirmed S. aurues isolates were put to oxacillin disk diffusion test to declare them MSSA. The MSSA confirmed isolates were subjected to various antibiotics for susceptibility profiling using Kirby Baur Disk Diffusion test. The present study found higher prevalence of MSSA from caprine origin (goat 83.33%) as compared to pet (cat 69.33%; dog 65.33%) and bovine origin (buffalo 26.66%; cattle 31.66%). The in-vitro findings of current study revealed oxytetracycline and gentamicin presented 100% efficacy against MSSA of all origins while the vancomycin presented >35%, >40% and > 65% resistance against MSSA isolated from bovine, caprine and pet origin respectively. However, ciprofloxacin was equally effective (50%) against MSSA from buffalo and cattle while >80% efficacy was noted against MSSA from cat and dogs. Linezolid and amoxicillin+ clavulanic acid were 77.78% and 66.67% sensitive to MSSA isolates from caprine milk. The present study found higher prevalence of MSSA from bovine, caprine and pet isolates with diversified pattern of susceptibility of different antibiotics from all sources.

scholarly journals Prevalence of methicillin-resistant Staphylococcus aureus and pattern of antimicrobial resistance in mastitis milk of cattle in Chitwan, Nepal

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Asmita Shrestha ◽  
Rebanta Kumar Bhattarai ◽  
Himal Luitel ◽  
Surendra Karki ◽  
Hom Bahadur Basnet
Keyword(s):  
Public Health ◽  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Subclinical Mastitis ◽  
World Health ◽  
Dairy Herds ◽  
Microbiological Analysis ◽  
Biochemical Tests ◽  
Methicillin Resistant ◽  
Milk Samples

Abstract Background The threat of methicillin-resistant Staphylococcus aureus (MRSA) exists globally and has been listed as a priority pathogen by the World Health Organization. One of the sources of MRSA emergence is livestock and its products, often raised in poor husbandry conditions. There are limited studies in Nepal to understand the prevalence of MRSA in dairy animals and its antimicrobial resistance (AMR) profile. A cross-sectional study was conducted in Chitwan, one of the major milk-producing districts of Nepal, from February 2018 to September 2019 to estimate the prevalence of MRSA in milk samples and its AMR profile. The collected milk samples (n = 460) were screened using the California Mastitis Test (CMT) and positive samples were subjected to microbiological analysis to isolate and identify S. aureus. Polymerase Chain Reaction (PCR) was used to identify the presence of the mecA gene and screen for MRSA. Results In total, 41.5% (191/460) of milk samples were positive in the CMT test. Out of 191 CMT positive milk samples, the biochemical tests showed that the prevalence of S. aureus was 15.2% (29/191). Among the 29 S. aureus isolates, 6.9% (2/29) were identified as MRSA based on the detection of a mecA gene. This indicates that that 1.05% (2/191) of mastitis milk samples had MRSA. The antibiotic sensitivity test showed that 75.9% (22/29) and 48.3% (14/29) S. aureus isolates were found to be sensitive to Cefazolin and Tetracycline respectively (48.3%), whereas 100% of the isolates were resistant to Ampicillin. In total 96.6% (28/29) of S. aureus isolates were multidrug-resistant (MDR). Conclusions This study revealed a high prevalence of S. aureus-mediated subclinical mastitis in dairy herds in Chitwan, Nepal, with a small proportion of it being MRSA carrying a mecA gene. This S. aureus, CoNS, and MRSA contaminated milk poses a public health risk due to the presence of a phenotype that is resistant to very commonly used antibiotics. It is suggested that dairy herds be screened for subclinical mastitis and treatments for the animals be based on antibiotic susceptibility tests to reduce the prevalence of AMR. Furthermore, future studies should focus on the Staphylococcus spp. to explore the antibiotic resistance genes in addition to the mecA gene to ensure public health.

scholarly journals Evaluation of Mannitol Salt Agar for Detection of Oxacillin Resistance in Staphylococcus aureus by Disk Diffusion and Agar Screening

1998 ◽  
Vol 36 (8) ◽  
pp. 2254-2257 ◽  
Author(s):  
Günter Kampf ◽  
Christoph Lecke ◽  
Ann-Katrin Cimbal ◽  
Klaus Weist ◽  
Henning Rüden
Keyword(s):  
Staphylococcus Aureus ◽  
Disk Diffusion ◽  
Diffusion Test ◽  
Mannitol Salt Agar ◽  
Disk Diffusion Test ◽  
Zone Diameter ◽  
Oxacillin Resistance

Mannitol salt agar was evaluated for detection of oxacillin resistance in 136 Staphylococcus aureus isolates. AllmecA-positive isolates (n = 54) were correctly categorized as oxacillin resistant by the disk diffusion test (1-μg disk; zone diameter, <16 mm); the specificity was 97.6%. Agar screening (2 μg of oxacillin per ml) revealed a sensitivity of 98.1% and a specificity of 95.1%.

Characterization of Toxin Genes and Antimicrobial Susceptibility of Staphylococcus aureus from Retail Raw Chicken Meat

2018 ◽  
Vol 81 (4) ◽  
pp. 528-533 ◽  
Author(s):  
SUIXIA LI ◽  
PANPAN WANG ◽  
JIALIN ZHAO ◽  
LUHONG ZHOU ◽  
PENGFEI ZHANG ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Health Hazard ◽  
Toxin Gene ◽  
Potential Health ◽  
Toxin Genes ◽  
Genes Encoding ◽  
Potential Health Hazard

ABSTRACTThe aim of this study was to investigate the toxin gene profile and antimicrobial resistance of Staphylococcus aureus isolates from raw chicken in the People's Republic of China. In total, 289 S. aureus isolates were characterized by antimicrobial susceptibility testing, and genes encoding enterotoxins, exfoliative toxins, Panton-Valentine leukocidin, and toxic shock syndrome toxin were revealed by PCR. Overall, 46.0% of the isolates were positive for one or more toxin genes. A high proportion of toxin genes were pvl (26.6%), followed by sej (12.5%), sea (9.0%), seh (8.3%), seb (6.9%), sec (6.9%), sed (4.8%), sei (3.1%), and see (2.4%). None of the isolates harbored seg, tsst-1, or exfoliative toxin genes. In total, 29 toxin gene profiles were obtained, and pvl (10.7%) was the most frequent genotype, followed by sea (5.9%), seb (4.8%), and sej (4.2%). Furthermore, 99.7% of the strains were resistant to at least one of the tested antimicrobial agents, and 87.2% of them displayed multidrug resistance. Resistance was most frequently observed to trimethoprim-sulfamethoxazole and erythromycin (86.2% for each), followed by tetracycline (69.9%), amoxicillin–clavulanic acid (45.0%), and ampicillin (42.6%). None of the strains were resistant to vancomycin. This study indicates that S. aureus isolates from raw chicken harbored multiple toxin genes and exhibited multiple antimicrobial resistance, which represents a potential health hazard for consumers.

scholarly journals Genetic Characterization of Methicillin-Resistant Staphylococcus aureus Isolates from Human Bloodstream Infections: Detection of MLSB Resistance

Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 375
Author(s):  
Vanessa Silva ◽  
Sara Hermenegildo ◽  
Catarina Ferreira ◽  
Célia M. Manaia ◽  
Rosa Capita ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Bloodstream Infections ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Accessory Gene ◽  
Spa Typing ◽  
Disk Diffusion Method ◽  
Methicillin Resistant

In this study we aimed to characterize antimicrobial resistance in methicillin-resistant Staphylococcus aureus (MRSA) isolated from bloodstream infections as well as the associated genetic lineages of the isolates. Sixteen MRSA isolates were recovered from bacteremia samples from inpatients between 2016 and 2019. The antimicrobial susceptibility of these isolates was tested by the Kirby–Bauer disk diffusion method against 14 antimicrobial agents. To determine the macrolide–lincosamide–streptogramin B (MLSB) resistance phenotype of the isolates, erythromycin-resistant isolates were assessed by double-disk diffusion (D-test). The resistance and virulence genes were screened by polymerase chain reaction (PCR). All isolates were characterized by multilocus sequence typing (MLST), spa typing, staphylococcal chromosomal cassette mec (SCCmec) typing, and accessory gene regulator (agr) typing. Isolates showed resistance to cefoxitin, penicillin, ciprofloxacin, erythromycin, fusidic acid, clindamycin, and aminoglycosides, confirmed by the presence of the blaZ, ermA, ermC, mphC, msrA/B, aac(6’)-Ie-aph(2’’)-Ia, and ant(4’)-Ia genes. Three isolates were Panton–Valentine-leukocidin-positive. Most strains (n = 12) presented an inducible MLSB phenotype. The isolates were ascribed to eight spa-types (t747, t002, t020, t1084, t008, t10682, t18526, and t1370) and four MLSTs (ST22, ST5, ST105, and ST8). Overall, most (n = 12) MRSA isolates had a multidrug-resistance profile with inducible MLSB phenotypes and belonged to epidemic MRSA clones.

scholarly journals New MLSBResistance Geneerm(43) in Staphylococcus lentus

2012 ◽  
Vol 56 (9) ◽  
pp. 4746-4752 ◽  
Author(s):  
Sybille Schwendener ◽  
Vincent Perreten
Keyword(s):  
Staphylococcus Aureus ◽  
Resistance Gene ◽  
Regulatory Region ◽  
Dna Fragments ◽  
Content Type ◽  
Resistance Phenotype ◽  
Inducible Resistance

ABSTRACTThe search for a specific rRNA methylase motif led to the identification of the new macrolide, lincosamide, and streptogramin B resistance geneerm(43) inStaphylococcus lentus. An inducible resistance phenotype was demonstrated by cloning and expressingerm(43) and its regulatory region inStaphylococcus aureus. Theerm(43) gene was detected in two different DNA fragments, of 6,230 bp and 1,559 bp, that were each integrated at the same location in the chromosome in severalS. lentusisolates of human, dog, and chicken origin.

Innovative approaches to treat Staphylococcus aureus biofilm-related infections

2017 ◽  
Vol 61 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Katharina Richter ◽  
Freija Van den Driessche ◽  
Tom Coenye
Keyword(s):  
Staphylococcus Aureus ◽  
Extracellular Matrix ◽  
Antimicrobial Resistance ◽  
Iron Metabolism ◽  
Communication System ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Antibiofilm Activity ◽  
Human Pathogen ◽  
Bacterial Communication

Many bacterial infections in humans and animals are caused by bacteria residing in biofilms, complex communities of attached organisms embedded in an extracellular matrix. One of the key properties of microorganisms residing in a biofilm is decreased susceptibility towards antimicrobial agents. This decreased susceptibility, together with conventional mechanisms leading to antimicrobial resistance, makes biofilm-related infections increasingly difficult to treat and alternative antibiofilm strategies are urgently required. In this review, we present three such strategies to combat biofilm-related infections with the important human pathogen Staphylococcus aureus: (i) targeting the bacterial communication system with quorum sensing (QS) inhibitors, (ii) a ‘Trojan Horse’ strategy to disturb iron metabolism by using gallium-based therapeutics and (iii) the use of ‘non-antibiotics’ with antibiofilm activity identified through screening of repurposing libraries.

Sign in / Sign up

Export Citation Format

Share Document