Bacteriocin Production, Antibiotic Susceptibility and Prevalence of Haemolytic and Gelatinase Activity in Faecal Lactic Acid Bacteria Isolated from Healthy Ethiopian Infants
Bacteriocin Production, Antibiotic Susceptibility and Prevalence of Haemolytic and Gelatinase Activity in Faecal Lactic Acid Bacteria Isolated from Healthy Ethiopian Infants
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DOI：
10.1007/s00248-012-0134-7
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发表时间：
2013-02-01
影响因子：
3.6
通讯作者：
Nes, Ingolf F.
中科院分区：
文献类型：
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作者：
Birri, Dagim Jirata;Brede, Dag Anders;Nes, Ingolf F.
本研究的目的是鉴定从埃塞俄比亚健康婴儿粪便样本中分离的乳酸菌（LAB），重点是细菌素的产生和抗生素敏感性。从28名健康的埃塞俄比亚婴儿获得150个LAB。分离菌株属于乳杆菌属（81/150）、肠球菌属（54/150）和链球菌属（15/150）。乳杆菌属在母乳喂养的婴儿中更丰富，而肠球菌在混合喂养的婴儿中占主导地位。从8名婴儿中分离出了产生细菌素的LAB菌种。从唾液链球菌中鉴定出一种新的细菌素，从鸟肠球菌中鉴定出一种IIa类Avicin A，从粪肠球菌中鉴定出一种IIa类细菌素，从大肠杆菌中鉴定出一种未知细菌素。faecalis和来自发酵乳杆菌菌株的两种未知细菌素以及来自加氏乳杆菌分离物的两种肽加氏菌素T。对9种抗生素进行的药敏试验表明，一些乳酸杆菌可能仅对红霉素（3%）和四环素（4%）产生耐药性。链球菌一般抗生素敏感，除了青霉素，他们表现出中间电阻。所有肠球菌均对氨苄青霉素敏感，13%的肠球菌对青霉素耐药.只有一个E。粪肠球菌分离株对万古霉素耐药。肠球菌对四环素（51%）和红霉素（26%）的耐药率较高，但多重耐药仅限于大肠埃希菌.粪肠球菌（47%）和屎肠球菌（33%）。肠球菌毒力性状的筛选显示2%为β-溶血性。溶细胞素结构基因在5种肠球菌中的检出率为28%，其中以E.粪球菌和棉子肠球菌。这项研究表明，细菌素的产生和抗生素耐药性是埃塞俄比亚婴儿粪便LAB的一个共同特征，而毒力因子的水平较低。
The objective of this study was to characterise lactic acid bacteria (LAB) isolated from faecal samples of healthy Ethiopian infants, with emphasis on bacteriocin production and antibiotic susceptibility. One hundred fifty LAB were obtained from 28 healthy Ethiopian infants. The isolates belonged to Lactobacillus (81/150), Enterococcus (54/150) and Streptococcus (15/150) genera. Lactobacillus species were more abundant in the breast-fed infants while Enterococcus dominated the mixed-fed population. Bacteriocin-producing LAB species were isolated from eight of the infants. Many different bacteriocins were identified, including one new bacteriocin from Streptococcus salivarius, avicin A (class IIa) from Enterococcus avium, one class IIa bacteriocin from Enterococcus faecalis strains, one unknown bacteriocin from E. faecalis and two unknown bacteriocins from Lactobacillus fermentum strains and the two-peptide gassericin T from Lactobacillus gasseri isolate. Susceptibility tests performed for nine antibiotics suggest that some lactobacilli might have acquired resistance to erythromycin (3 %) and tetracycline (4 %) only. The streptococci were generally antibiotic sensitive except for penicillin, to which they showed intermediate resistance. All enterococci were susceptible to ampicillin while 13 % showed penicillin resistance. Only one E. faecalis isolate was vancomycin-resistant. Tetracycline (51 %) and erythromycin (26 %) resistance was prevalent among the enterococci, but multidrug resistance was confined to E. faecalis (47 %) and Enterococcus faecium (33 %). Screening of enterococcal virulence traits revealed that 2 % were beta-haemolytic. The structural genes of cytolysin were detected in 28 % of the isolates in five enterococcal species, the majority being E. faecalis and Enterococcus raffinosus. This study shows that bacteriocin production and antibiotic resistance is a common trait of faecal LAB of Ethiopian infants while virulence factors occur at low levels.