The study was intended for identification and characterization of Staphylococcus aureus isolated from raw cow milk. A total of 47 milk samples were collected from Sheshmore, Shutiakhali and Bangladesh Agricultural University Dairy Farm, Mymensingh. Using bacteriological, biochemical and PCR-based identification schemes, 12 (25.53%) isolates were confirmed as S. aureus. All the isolates showed β-hemolysis on 5% sheep blood agar. S. aureus specific nuc gene (target size 279-bp) was amplified in the cases of all isolates. The isolates were found as resistant to Penicillin (100%), Erythromycin (75%) and Amoxicillin (100%). On the other hand, the isolates were sensitive to Ciprofloxacin (83.33%), Oxacillin (100%), Cloxacillin (100%) and Neomycin (100%). The isolated S. aureus showed increased resistance to broad spectrum antibiotic (e.g., Ciprofloxacin). As many people have a tendency to drink raw milk and raw milk products, there is high risk of S. aureus infection in human.

The aim of this study was to evaluate the antimicrobial activity and determine the minimum bactericidal concentration (MBC) of the essential oils derived from Origanum vulgare (oregano), Melaleuca alternifolia (tea tree), Cinnamomum cassia (cassia), and Thymus vulgaris (white thyme) against Salmonella Typhimurium, Salmonella Enteritidis, Escherichia coli, Staphylococcus aureus and Enterococcus faecalis. The study also investigated the ability of these different bacterial strains to develop adaptation after repetitive exposure to sub-lethal concentrations of these essential oils. The MBC of the essential oils studied was determined by disc diffusion and broth dilution methods. All essential oils showed antimicrobial effect against all bacterial strains. In general, the development of adaptation varied according to the bacterial strain and the essential oil (tea tree > white thyme > oregano). Therefore, it is important to use essential oils at efficient bactericidal doses in animal feed, food, and sanitizers, since bacteria can rapidly develop adaptation when exposed to sub-lethal concentrations of these oils.

OBJECTIVE To determine by use of an in vitro model the potential for translocating sufficient numbers of bacteria into a joint during arthrocentesis through cellulitic tissue to cause sepsis. SAMPLE Culture media containing 4 concentrations of Staphylococcus aureus and needles of 3 sizes. PROCEDURES Needles (22, 20, and 19 gauge) were inserted through Mueller-Hinton agar that contained known concentrations of S aureus (10(3),10(4),10(5), and 10(6) CFUs/mL). After a needle exited through the medium, any agar plug within the needle bore was ejected into a sterile syringe and the contaminated portion of the needle was harvested. Sterile saline (0.9% NaCl) solution was used to emulsify the agar plug and wash the contaminated portion of the needle. The resulting solution was cultured to determine the number of bacterial CFUs that could be deposited into a joint during arthrocentesis through contaminated tissue. RESULTS Needle gauge and bacterial concentration were both associated with the number of bacterial CFUs deposited after insertion through contaminated agar. Although all needle sizes were capable of bacterial translocation sufficient to cause septic arthritis, ORs for 20- and 22-gauge needles translocating > 33 CFUs of S aureus were significantly higher than the OR for a 19-gauge needle. The ORs for 20- or 22-gauge needles translocating > 33 CFUs of S aureus (the minimum population of S aureus known to cause joint sepsis) were 0.22. CONCLUSIONS AND CLINICAL RELEVANCE Results for this in vitro model indicated that caution should be used when performing arthrocentesis through cellulitic tissue.

Oregano (Origanum vulgare) is an aromatic herb belonging to the Lamiaceae family. This study evaluated the therapeutic effect of oregano essential oil (OEO) on clinical bovine mastitis caused by Staphylococcus (S.) aureus and / or Escherichia (E.) coli. Thirty - two quarters from 18 lactating cows with subclinical mastitis were selected from a dairy farm and were divided into 4 groups (8 quarters / group): negative control (CON), positive control (GEN) and two OEO-treated groups (OEO-1 and OEO-2). Each group was intramammarily treated with saline, 10 g/tube of gentamicin ointment, and single and double doses of 0.9 mL OEO ointment twice a day for three days, respectively. After the treatments, physical udder conditions were greatly improved in GEN and OEO groups. In CON group, somatic cell counts (SCCs), number of white blood cells (WBC) and bacteria were increased. However, in OEO groups, SCCs and number of WBC were significantly decreased and S. aureus and E. coli were not detected in milk as compared with those before the treatments as well as GEN group. These results suggest that OEO may be a useful alternative to antibiotics for the control of subclinical bovine mastitis caused by S. aureus and/or E. coli.

The aim of this study was to investigate the bacteria found in different parts of the genital system in cows and the susceptibility to different types of antibiotics. The genital systems of sixteen cows were collected from Al-Hilla, Iraq slaughterhouse. Isolation and identification of bacteria were made for each part of the genital system and antibiotic susceptibility tests was conducted to the isolated bacteria. The results of this study indicated that there were several types of bacteria present in the genital systems of cows. Different species of bacteria were isolated from the samples including, Escherichia coli (28.97)%, Klebsiella spp. (16.82)%, Salmonella spp. (14.95)%, Proteus spp. (13.08)%, Staphylococcus aureus (11.21)%, Staphylococcus epidermidis (8.41)% and Streptococcus spp. (6.54)%. In vitro susceptibility towards different types of antibiotic indicated high susceptibility of Escherichia coli to antibiotic group impenem and ciprofloxacin, while Klebsiella spp. was found to be most susceptible to ciprofloxacin and amikacin. Both Escherichia coli and Klebsiella spp. showed resistance to piperacillin and tetracycline. It was concluded that Escherichia coli was the most predominant bacteria in genital system of cows and were most susceptible to antibiotic impenem and ciprofloxacin.