This study was conducted to determine the prevalence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in pigs, farm workers, and the environment in northern Thailand, and to assess LA-MRSA isolate phenotypic characteristics. One hundred and four pig farms were randomly selected from the 21,152 in Chiang Mai and Lamphun provinces in 2012. Nasal and skin swab samples were collected from pigs and farm workers. Environmental swabs (pig stable floor, faucet, and feeder) were also collected. MRSA was identified by conventional bacterial culture technique, with results confirmed by multiplex PCR and multi locus sequence typing (MLST). Herd prevalence of MRSA was 9.61% (10 of 104 farms). Among pigs, workers, and farm environments, prevalence was 0.68% (two of 292 samples), 2.53% (seven of 276 samples), and 1.28% (four of 312 samples), respectively. Thirteen MRSA isolates (seven from workers, four from environmental samples, and two from pigs) were identified as Staphylococcal chromosomal cassette mec IV sequences type 9. Antimicrobial sensitivity tests found 100% of the MRSA isolates resistant to clindamycin, oxytetracycline, and tetracycline, while 100% were susceptible to cloxacillin and vancomycin. All possessed a multidrug-resistant phenotype. This is the first evidence of an LA-MRSA interrelationship among pigs, workers, and the farm environment in Thailand.
*Animal Husbandry ; Animals ; Cross-Sectional Studies ; Genotype ; Humans ; Methicillin-Resistant Staphylococcus aureus/classification/*genetics/*isolation & purification ; Microbial Sensitivity Tests/veterinary ; Molecular Sequence Data ; Multilocus Sequence Typing/veterinary ; Multiplex Polymerase Chain Reaction/veterinary ; Occupational Diseases/*epidemiology/microbiology ; Phylogeny ; Prevalence ; Sequence Analysis, DNA/veterinary ; Staphylococcal Infections/*epidemiology/microbiology ; Swine ; Swine Diseases/*epidemiology/microbiology ; Thailand/epidemiology

The prevalence, virulence potential, and antibiotic resistance of ophthalmic Staphylococcus pseudintermedius (SP) isolated from dogs were examined. Sixty-seven Staphylococcus species were isolated from ophthalmic samples and surveyed for species-specific sequences in the Staphylococcus intermedius group (SIG) nuclease gene (SInuc), exfoliative toxin gene for SIG (siet), and antibiotic resistance genes (blaZ and mecA). PCR-restriction fragment length polymorphism analysis of the pta gene was also performed. Fifty isolates were identified as SIG strains, all of which were found to be SP. The blaZ gene was detected in 42 of the 50 SP strains and mecA gene was observed in 18 of the 50 SP strains. The 50 SP strains were most susceptible to amoxicillin/clavulanic acid (94%) and chlorampenicol (70%), and highly resistant to tetracycline (94%) and penicillin (92%). It was also found that 16 (88.9%) mecA-positive SP strains were resistant to oxacillin, tetracycline and penicillin. All mecA-positive SP were resistant to more than four of the eight tested antibiotics and therefore considered SP with multi-drug resistance (MDR). Our results indicate a high prevalence of antibiotic resistance genes in ophthalmic SP along with a close relationship between MDR SP strains and the mecA gene. Based on our findings, judicious administration of antibiotics to companion dogs is necessary.
Animals ; Anti-Bacterial Agents/*therapeutic use ; Dog Diseases/drug therapy/*microbiology ; Dogs ; Drug Resistance, Bacterial ; Drug Resistance, Multiple, Bacterial ; Eye Infections, Bacterial/drug therapy/microbiology/*veterinary ; Microbial Sensitivity Tests/veterinary ; Multiplex Polymerase Chain Reaction ; Staphylococcal Infections/drug therapy/microbiology/*veterinary ; Staphylococcus/*drug effects/isolation & purification

We investigated the distribution of commensal staphylococcal species and determined the prevalence of multi-drug resistance in healthy cats and dogs. Risk factors associated with the carriage of multi-drug resistant strains were explored. Isolates from 256 dogs and 277 cats were identified at the species level using matrix-assisted laser desorption ionisation-time of flight mass spectrometry. The diversity of coagulase-negative Staphylococci (CNS) was high, with 22 species in dogs and 24 in cats. Multi-drug resistance was frequent (17%) and not always associated with the presence of the mecA gene. A stay in a veterinary clinic in the last year was associated with an increased risk of colonisation by multi-drug resistant Staphylococci (OR = 2.4, 95% CI: 1.1~5.2, p value LRT = 0.04). When identifying efficient control strategies against antibiotic resistance, the presence of mechanisms other than methicillin resistance and the possible role of CNS in the spread of resistance determinants should be considered.
Animals ; Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/genetics/metabolism ; Cat Diseases/epidemiology/*microbiology ; Cats ; Coagulase/genetics/metabolism ; Dog Diseases/epidemiology/*microbiology ; Dogs ; *Drug Resistance, Multiple, Bacterial ; Female ; Male ; Prevalence ; Risk Factors ; Seasons ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/veterinary ; Staphylococcal Infections/epidemiology/microbiology/*veterinary ; Staphylococcus/classification/genetics/*isolation & purification ; Switzerland/epidemiology

The sequences of the ccrAB genes from bovine-, canine- and chicken-originating methicillin-resistant Staphylococcus (S.) epidermidis (MRSE) and bovine methicillin-resistant Staphylococcus (S.) aureus (MRSA) were compared to investigate the frequency of intra-species horizontal transfer of the staphylococcal cassette chromosome mec (SCCmec) complex. Nineteen MRSE strains were isolated from bovine milk, chickens, and dogs, and their genetic characteristics were investigated by multilocus sequence typing and SCCmec typing. Among the animal MRSE strains, the most frequent SCCmec type was type IV, which consisted of the type B mec complex and ccrAB type 2. The ccrA2 and ccrB2 genes were sequenced from the bovine, chicken and canine MRSE strains and compared with those of the bovine MRSA strains. The sequences generally clustered as MRSA and MRSE groups, regardless of the animal source. Additionally, no bovine MRSE sequence was associated with the bovine MRSA groups. Although most of the bovine MRSE and MRSA isolates possessed SCCmec type IV sequences, our results suggest that the intra-species gene transfer of the SCCmec complex between bovine S. aureus and bovine S. epidermidis strains is not a frequent event.
Animals ; Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/*genetics/metabolism ; Bacterial Typing Techniques/veterinary ; Cattle ; Cattle Diseases/epidemiology/metabolism ; Chickens ; Dog Diseases/epidemiology/metabolism ; Dogs ; *Drug Resistance, Bacterial ; *Gene Transfer, Horizontal ; Methicillin/*pharmacology ; Methicillin-Resistant Staphylococcus aureus/genetics/isolation & purification ; Milk/microbiology ; Multilocus Sequence Typing/veterinary ; Poultry Diseases/epidemiology/metabolism ; Prevalence ; Republic of Korea/epidemiology ; Staphylococcal Infections/epidemiology/microbiology/*veterinary ; Staphylococcus epidermidis/genetics/isolation & purification

OBJECTIVETo investigate the prevalence of methicillin-resistant staphylococci (MRS) which is a potencial risk factor of transmission between animals and humans in different types of horses (harness racing-horses, breeding mares and riding-horses) and to compare the antimicrobial resistance of the isolates.

METHODSA total of 191 healthy horses, housed at different locations of the Campania Region (Italy), were included in the study. Nasal swab samples were collected from each nostril of the horses. The mecA gene was detected by a nested PCR technique. Antibiotic susceptibility was tested for each isolate.

RESULTSMRS was isolated from nasal samples of 68/191 (35.6%; 95% CI: 28.9%-42.9%) healthy horses. All isolates were coagulase-negative with the exception of two coagulase-positive MRS strains, identified as Staphylococcus aureus and Staphylococcus pseudintermedius, 2/83 (2.4%; 95% CI: 0.4%-9.2%). Interestingly, both coagulase-positive MRS isolates were from harness racing-horses. These horses also presented a significantly higher positivity for MRS (53.3%; 95% CI: 40.1%-66.1%) than the breeding mares and riding-horses groups. Antibiotic susceptibility testing showed difference between isolates due to different origins except for an almost common high resistance to aminopenicillins, such as ampicillin and amoxicillin.

CONCLUSIONSIt can be concluded that harness racing-horses may act as a significant reservoir of MRS as compared to breeding mares and riding-horses.

Animals ; Anti-Bacterial Agents ; pharmacology ; Coagulase ; Drug Resistance, Multiple, Bacterial ; Female ; Horse Diseases ; epidemiology ; microbiology ; Horses ; Italy ; epidemiology ; Male ; Methicillin-Resistant Staphylococcus aureus ; drug effects ; isolation & purification ; Microbial Sensitivity Tests ; veterinary ; Polymerase Chain Reaction ; veterinary ; Prevalence ; Staphylococcal Infections ; epidemiology ; microbiology ; veterinary

Changes in udder health and antibiotic resistance of mastitis pathogens isolated from dairies upon conversion from conventional to organic management over a 3-year period was studied. Coagulase-negative staphylococci (CNS) were the most prevalent mastitis pathogens isolated. CNS were significantly less resistant to beta-lactam antibiotics when isolated from milk after the herd transitioned to organic management. Cessation of the use of antimicrobial therapies in dairies in combination with organic management could lead to a reduction in the antimicrobial resistance of mastitis pathogens.
Ampicillin/pharmacology ; Animals ; Anti-Bacterial Agents/pharmacology ; Cattle ; Cephalothin/pharmacology ; Cloxacillin/pharmacology ; Drug Resistance, Microbial ; Female ; Lactation ; Mastitis, Bovine/*microbiology ; Microbial Sensitivity Tests ; Organic Agriculture ; Penicillins/pharmacology ; Prevalence ; Staphylococcal Infections/microbiology/*veterinary ; Staphylococcus/*drug effects/*isolation & purification

Sensitivity to commercial teat dips (nonoxinol-9 iodine complex and chlorhexidine digluconate) of 56 Staphylococcus (S.) aureus strains isolated from quarter milk samples of various German dairy herds treated with different teat dipping schemes was investigated in this study. The minimum inhibitory concentration was determined using a broth macrodilution method according to the German Veterinary Association guidelines. The main objective of the current study was to induce in vitro resistance induction of S. aureus to chemical disinfectants. Ten different strains were repeatedly passed ten times in growth media with sub-lethal concentrations of disinfectants. Nine strains showed a significant reduction in susceptibility to the nonoxinol-9 iodine complex but only one strain developed resistance to chlorhexidine digluconate. Stability of the acquired resistance was observed in all S. aureus strains adapted to the nonoxinol-9 iodine complex and chlorhexidine digluconate. In contrast, simultaneous resistance to different antibiotics was not observed in any of the ten investigated S. aureus strains. However, the isolates exhibited a high degree of resistance to penicillin G. Based on these results, resistance of S. aureus to chemical disinfectants may be more likely to develop if the chemicals are used at concentrations lower than that required for an optimal biocidal effect.
Animals ; Anti-Bacterial Agents/pharmacology ; Cattle ; Chlorhexidine/*pharmacology ; Disinfectants/pharmacology ; Dose-Response Relationship, Drug ; Drug Resistance, Bacterial ; Female ; Germany/epidemiology ; Iodine/chemistry/*pharmacology ; Mastitis, Bovine/epidemiology/*microbiology ; Nonoxynol/*pharmacology ; Staphylococcal Infections/epidemiology/microbiology/*veterinary ; Staphylococcus aureus/classification/*drug effects

The present study determined the genetic relationships between 41 Staphyloccocus (S.) aureus isolates from bovines, humans, and food using a single enzyme amplified fragment length polymorphism (AFLP) technique. We evaluated the prevalence of staphylococcal enterotoxin (SE) genes and other virulence gene determinants by PCR. The identification of S. aureus was based on culturing and biochemical tests, and by amplifying a specific section of the 23S rRNA gene. PCR amplification of the SE genes (sea, seb, sec, see, seg, seh, and sei) singly or in combination was observed. Most isolates of bovine origin harbored hla (84%) and cap5 (74%), while most isolates from humans harbored hla (73%), cap8 (91%), and fnbA (100%). Strains from food sources were positive for hla (100%), cap5 (100%), and cap8 (64%) unlike isolates from humans or bovines. A single enzyme AFLP analysis revealed a correlation between AFLP clusters of some strains and the source of the isolates The genotypic results of the present study might help to better understand the distribution of prevalent S. aureus clones among humans, bovines, and food and will help control S. aureus infections in Indonesia.
Amplified Fragment Length Polymorphism Analysis ; Animals ; Bacterial Proteins/genetics/metabolism ; Cattle ; Female ; *Food Microbiology ; Gene Expression Regulation, Bacterial ; Humans ; Indonesia/epidemiology ; Mastitis, Bovine/epidemiology/microbiology ; Phylogeny ; Staphylococcal Infections/epidemiology/microbiology/*veterinary ; Staphylococcus aureus/*genetics

Staphylococcus (S.) aureus is a common infectious agent of bovine chronic mastitis, a disease that is difficult to eradicate. The abilities of Staphylococci to be internalized and form a biofilm can contribute to host immunological defence evasion that subsequently impairs antimicrobial therapy. The invasive capability of six S. aureus field isolates with different biofilm-forming profiles was compared in vitro using a bovine mammary epithelial cell line. This was further confirmed in primary cell cultures using fluorescent rRNA probes against S. aureus. The results suggest that S. aureus invasion levels are not related to biofilm formation.
Animals ; *Biofilms ; Cattle ; Cell Line ; Colony Count, Microbial/veterinary ; Epithelial Cells/microbiology ; Female ; In Situ Hybridization, Fluorescence ; Mastitis, Bovine/*microbiology ; Portugal ; Staphylococcal Infections/*veterinary ; Staphylococcus aureus/classification/genetics/immunology/*physiology ; Virulence Factors/i

The Staphylococcus (S.) intermedius group (SIG) has been a main research subject in recent years. S. pseudintermedius causes pyoderma and otitis in companion animals as well as foodborne diseases. To prevent SIG-associated infection and disease outbreaks, identification of both staphylococcal exotoxins and staphylococcal cassette chromosome mec (SCCmec) types among SIG isolates may be helpful. In this study, it was found that a single isolate (one out of 178 SIG isolates examined) harbored the canine enterotoxin SEC gene. However, the S. intermedius exfoliative toxin gene was found in 166 SIG isolates although the S. aureus-derived exfoliative toxin genes, such as eta, etb and etd, were not detected. SCCmec typing resulted in classifying one isolate as SCCmec type IV, 41 isolates as type V (including three S. intermedius isolates), and 10 isolates as non-classifiable. Genetic relatedness of all S. pseudintermedius isolates recovered from veterinary staff, companion animals, and hospital environments was determined by pulsed-field gel electrophoresis. Strains having the same band patterns were detected in S. pseudintermedius isolates collected at 13 and 18 months, suggesting possible colonization and/or expansion of a specific S. pseudintermedius strain in a veterinary hospital.
Animals ; Bacterial Toxins/genetics/metabolism ; Cat Diseases/epidemiology/*microbiology ; Cats ; Chromosomes, Bacterial/genetics/metabolism ; Dog Diseases/epidemiology/*microbiology ; Dogs ; Electrophoresis, Gel, Pulsed-Field/veterinary ; Enterotoxins/genetics/metabolism ; Exfoliatins/genetics/metabolism ; Exotoxins/*genetics/metabolism ; Hospitals, Animal ; Humans ; Medical Staff, Hospital ; Molecular Sequence Data ; Pets/microbiology ; Polymerase Chain Reaction/veterinary ; Republic of Korea/epidemiology ; Staphylococcal Infections/epidemiology/microbiology/*veterinary ; Staphylococcus/genetics/isolation & purification ; Staphylococcus intermedius/*genetics/*isolation & purification