Primary isolation of Mycobacterium bovis from bovine tissues: Conditions for maximising the number of positive cultures

被引:46
作者
Corner, L. A. L. [1 ]
Gormley, E. [1 ]
Pfeiffer, D. U. [2 ]
机构
[1] UCD, Vet Sci Ctr, Sch Vet Med, Dublin 4, Ireland
[2] Royal Vet Coll, Hatfield L9 7TA, Herts, England
关键词
Mycobacterium bovis; Tuberculosis; Cattle diseases; Primary isolation; Culture medium; Incubation time; INTERFERON-GAMMA; AGAR MEDIUM; TUBERCULOSIS; LESIONS; IDENTIFICATION; LABORATORIES; DIAGNOSIS; CATTLE; MEDIA;
D O I
10.1016/j.vetmic.2011.10.016
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
In studies of Mycobacterium bovis infection in animals a definitive diagnosis requires the isolation of the organism. However, the optimum conditions for the primary isolation of M. bovis have not been determined. The aim of this study was to determine for primary isolation of M. bovis, (a) the incubation time required to achieve maximum sensitivity (i.e., the number of positive samples identified), (b) the effect of decontaminants on bacterial growth rates, and (c) the influence of media and the number of slopes of media on the number of positive samples detected. Two agar-based media, modified Middlebrook 7H11 (7H11) and tuberculosis blood agar (883), and an egg-based medium, Stonebrink's (SB) were compared. Three decontaminants, 2% (w/v) sodium hydroxide (NaOH), 0.75% (w/v) and 0.075% (w/v) cetylpyridinium chloride (CPC, also called hexadecylpyridinium chloride, HPC) and 0.5% (w/v) benzalkonium chloride (BC) were evaluated against treatment with sterile distilled water. The inoculated media slopes were incubated for up to 15 weeks. Colonies first appeared after 2 weeks on all media types and 75% of positive slopes were identified by 8 weeks. An incubation time of 15 weeks was required to identify all positive samples. The slowest growth was associated with inocula that contained the fewest viable bacilli. The time to the appearance of colonies was influenced by medium type: the median time to detection of colonies was 28 days on 7H11 and B83, and 36 days on SB. However, SB returned the greatest number of positive samples. Decontamination procedures increased the minimum incubation time required to detect positive cultures, probably due to the toxic effect of the decontaminants. Increasing the number of inoculated slopes resulted in an increased number of positive samples and a decreased time to the detection of colonies. Overall, the detection of M. bovis was significantly influenced by the choice of media, the decontaminant and the duration of incubation of cultures. (C) 2011 Elsevier B.V. All rights reserved.
引用
收藏
页码:162 / 171
页数:10
相关论文
共 24 条
[1]  
Baron EJ, 2007, MANUAL OF CLINICAL MICROBIOLOGY, 9TH ED, P1
[2]  
Bodadilla-del-Valle M., 2003, J CLIN MICROBIOL, V41, P4487
[3]   On the nature of Mycobacterium tuberculosis-latent bacilli [J].
Cardona, PJ ;
Ruiz-Manzano, J .
EUROPEAN RESPIRATORY JOURNAL, 2004, 24 (06) :1044-1051
[4]  
Collins C., 1997, Tuberculosis bacteriology: organisation and practice
[5]   COMPARISON OF MEDIA USED FOR THE PRIMARY ISOLATION OF MYCOBACTERIUM-BOVIS BY VETERINARY AND MEDICAL DIAGNOSTIC LABORATORIES [J].
CORNER, LA ;
NICOLACOPOULOS, C .
AUSTRALIAN VETERINARY JOURNAL, 1988, 65 (07) :202-205
[6]   DETERMINATION OF THE OPTIMUM CONCENTRATION OF DECONTAMINANTS FOR THE PRIMARY ISOLATION OF MYCOBACTERIUM-BOVIS [J].
CORNER, LA ;
TRAJSTMAN, AC ;
LUND, K .
NEW ZEALAND VETERINARY JOURNAL, 1995, 43 (04) :129-133
[7]   IDENTIFICATION OF MYCOBACTERIUM-BOVIS ISOLATES USING A MONOCLONAL-ANTIBODY [J].
CORNER, LA ;
JOHN, M ;
BUNDESEN, PG ;
WOOD, PR .
VETERINARY MICROBIOLOGY, 1988, 18 (02) :191-196
[8]   AN EVALUATION OF 1-HEXADECYLPYRIDINIUM CHLORIDE AS A DECONTAMINANT IN THE PRIMARY ISOLATION OF MYCOBACTERIUM-BOVIS FROM BOVINE LESIONS [J].
CORNER, LA ;
TRAJSTMAN, AC .
VETERINARY MICROBIOLOGY, 1988, 18 (02) :127-134
[9]  
Costello E, 1998, IRISH VET J, V51, P248
[10]   ADVANTAGES OF A NEW AGAR MEDIUM IN THE PRIMARY ISOLATION OF MYCOBACTERIUM-BOVIS [J].
COUSINS, DV ;
FRANCIS, BR ;
GOW, BL .
VETERINARY MICROBIOLOGY, 1989, 20 (01) :89-95