• Korean Journal of Veterinary Research
• /
• v.26 no.2
• /
• pp.237-243
• /
• 1986

This paper deals with the incidence of bovine mastitis for 743 quarters and distribution of Staphylococci for the quarter and 70 bulk milk samples in the northern area of Gyeongbuk during the period from January to December 1984. Isolated Staphylococci were examined for species, subgroups, antibiotic resistance and penicillinase production. The results obtained were summarized as follows : A total of 25(73.5%) of 34 herds, 102(54.3%) of 188 cows and 208(30.3%) of 743 quarters were found to be infected with subclinical mastitis. A total of 83(83.1%) of 102 cows, 94(45.2%) of 208 mastitic quarters and 55(78.6%) of 70 bulk milk samples were isolated Staphylococci. Three hundred and eighteen strains of Staphylococci were classified into 11 species. Of these speoies, S. aureus from mastitis and S. sciuri from bulk milk were found most frequently, followed by S. epidermidis, S. simulans, S. cohnii, S. haemolyticus, S. xylosus, S. hyicus subsp. chromogenes, S. saprophyticus, S. warneri, S hyicus subsp. hyicus. Subgroups of catalase-positive and negative cocci were belonged most frequently to subgroup I, and subgroups III and III b, respectively. The method of Pelzer of al(97.8%) was more classified than that of Baird-Parker (68.5%). One hundred and sixty one strains(50.6%) of 318 Staphylococci isolates were resistance to one or more antibiotics such as ampicillin, chloramphenicol, gentamicin, kanamycin, streptomycin, and tetracycline. Isolates from subclinical mastitis were more resistant to antibiotics than its from bulk milk. Of the 318 Staphylococci Isolates, 128(40.3%) gave positive reaction for the penicillinase test, all of ampicillin resistance strains produced this emzyme.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.1
• /
• pp.85-91
• /
• 2001

To construct an efficient Bacillus subtilis expression vector, strong promoters were isolated from the chromosomal DNA libraries of Clostridium acetobutylicum ATCC 4259, Thermoactinomyces sp. E79, and Bacillus thermoglucosidasius KCTC 3400. The $P_{C27}$ promoter cloned from the clostridial chromosmal DNA showed a 5-fold higher promoter strength than the $P_{SP02}$ promoter in the expression of the cat gene, and its sequence was estimated as an upstream region of the predicted hypothetical gene (tet-R family bacterial transcription regulator gene) in C. acetobutylicum. As a promoter element, $P_{C27}$ exhibited putative nucleotide sequences that can bind with bacterial RNAP and the 3'end of the 16S rRNA just upstream of the start codon. In addition, the promoter activity of $P_{C27}$ was distinctively repressed in the presence of glucose. Using $P_{C27}$ as the promoter element, a glucose controllable B. subtilis expression vector was constructed and the lipase gene from Staphylococcus haemolyticus KCTC 8957P was expressed in B. subtilis. When compared with the lipase expression by the T7 promoter induced by IPTG in E. coli, the $P_{C27}$ promoter showed about a 1.5-fold higher expression level in B. subtilis than that without induction.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.9
• /
• pp.1340-1349
• /
• 2017

Objective: This study aimed to evaluate the microbiological and cellular milk profile for the diagnosis of subclinical mastitis in female buffaloes and to assess risk factors for predisposition of the disease. Methods: Analyses were carried out by standard plate count (SPC), identification of species and antibiotic resistance, somatic cell count (SCC), electrical electrical conductivity of milk (ECM), and lactoferrin content in milk. Teat cups were swabbed to evaluate risk factors, observing hyperkeratosis, milking vacuum pressure and cleanliness of the site. Hence, 30 female buffaloes were randomly selected (15 from a group in early lactation and 15 in late lactation). Results: The most common bacteria in the microbiological examination were Staphylococcus spp., Streptococcus spp. and Corynebacterium sp. In the antibiotic sensitivity test, 10 (58.82%) of the 17 antibiotics tested were sensitive to all isolates, and resistant bacteria were Streptococcus uberis, Streptococcus dysgalactiae, Streptococcus haemolyticus, and Escherichia coli. It was observed that positive samples in the microbiological examination showed total bacterial count between $9.10{\times}10^3$ to $6.94{\times}10^6$ colony forming units/mL, SCC between 42,000 to 4,320,000 cells/mL and ECM ranging from 1.85 to 7.40 mS/cm. It was also found that the teat cups had high microbial counts indicating poor hygiene, and even faults in the cleanliness of the animals' waiting room were observed. It is concluded that values of SCC above 537,000 cells/mL and ECM above 3.0 mS/mL are indications of mammary gland infection for this herd; however, the association of these values with a microbiological analysis is necessary to more accurately evaluate the health status of mammary glands with subclinical mastitis. Conclusion: Through phenotypic characterization of bacteria involved in the samples, the genera Staphylococcus spp., Streptococcus spp., and Corynebacterimum bovis were the most prevalent in this study. Faults in environment and equipment hygienization are factors that are directly associated with mastitis.