Gad Gamal Fadl M, Abdel-Hamid Ahmed M, Farag Zeinab Shawky H
Microbiology Department Faculty of Pharmacy El-Minia University , Egypt.
Botany and Microbiology Department Faculty of Science El-Minia University , Egypt.
Braz J Microbiol. 2014 May 19;45(1):25-33. doi: 10.1590/s1517-83822014000100005. eCollection 2014.
A total of 244 lactic acid bacteria (LAB) strains were isolated from 180 dairy and pharmaceutical products that were collected from different areas in Minia governorate, Egypt. LAB were identified phenotypically on basis of morphological, physiological and biochemical characteristics. Lactobacillus isolates were further confirmed using PCR-based assay. By combination of phenotypic with molecular identification Lactobacillus spp. were found to be the dominant genus (138, 76.7%) followed by Streptococcus spp. (65, 36.1%) and Lactococcus spp. (27, 15%). Some contaminant organisms such as (Staphylococcus spp., Escherichia coli, Salmonella spp., mould and yeast) were isolated from the collected dairy samples but pharmaceutical products were free of such contaminants. Susceptibility of LAB isolates to antibiotics representing all major classes was tested by agar dilution method. Generally, LAB were highly susceptible to Beta-lactams except penicillin. Lactobacilli were resistant to vancomycin, however lactococci and streptococci proved to be very susceptible. Most strains were susceptible to tetracycline and showed a wide range of streptomycin MICs. The MICs of erythromycin and clindamycin for most of the LAB were within the normal range of susceptibility. Sixteen Lactobacillus, 8 Lactococcus and 8 Streptococcus isolates including all tetracycline and/or erythromycin resistant strains were tested for the presence of tetracycline and/or erythromycin resistant genes [tet(M) and/or erm(B)]. PCR assays shows that some resistant strains harbor tet(M) and/or erm(B) resistance genes.
从埃及明亚省不同地区收集的180种乳制品和药品中，共分离出244株乳酸菌（LAB）菌株。根据形态、生理和生化特征对LAB进行表型鉴定。使用基于PCR的检测方法进一步确认乳酸杆菌分离株。通过表型与分子鉴定相结合，发现乳酸杆菌属是优势菌属（138株，占76.7%），其次是链球菌属（65株，占36.1%）和乳球菌属（27株，占15%）。从收集的乳制品样本中分离出了一些污染微生物，如葡萄球菌属、大肠杆菌、沙门氏菌属、霉菌和酵母菌，但药品中没有此类污染物。采用琼脂稀释法检测LAB分离株对代表所有主要类别的抗生素的敏感性。一般来说，LAB对β-内酰胺类抗生素高度敏感，但对青霉素不敏感。乳酸杆菌对万古霉素耐药，然而乳球菌和链球菌对万古霉素非常敏感。大多数菌株对四环素敏感，对链霉素的最低抑菌浓度（MIC）范围较宽。大多数LAB对红霉素和克林霉素的MIC在正常敏感范围内。对16株乳酸杆菌、8株乳球菌和8株链球菌分离株（包括所有对四环素和/或红霉素耐药的菌株）检测四环素和/或红霉素耐药基因[tet(M)和/或erm(B)]的存在情况。PCR检测表明，一些耐药菌株携带tet(M)和/或erm(B)耐药基因。
