Background
Mycobacterium tuberculosis complex (MTBC) and Non-tuberculosis Mycobacterium (NTM) infections differ clinically, making rapid identification and drug susceptibility testing (DST) very critical for infection control and drug therapy. This study aims to use World Health Organization (WHO) approved line probe assay (LPA) to differentiate mycobacterial isolates obtained from tuberculosis (TB) prevalence survey in Ghana and to determine their drug resistance patterns.MethodsA retrospective study was conducted whereby a total of 361 mycobacterial isolates were differentiated and their drug resistance patterns determined using GenoType Mycobacterium Assays: MTBC and CM/AS for differentiating MTBC and NTM as well MTBDRplus and NTM-DR for DST of MTBC and NTM respectively.ResultsOut of 361 isolates, 165 (45.7%) MTBC and 120 (33.2%) NTM (made up of 14 different species) were identified to the species levels whiles 76 (21.1%) could not be completely identified. The MTBC comprised 161 (97.6%) Mycobacterium tuberculosis and 4 (2.4%) Mycobacterium africanum. Isoniazid and rifampicin monoresistant MTBC isolates were 18/165 (10.9%) and 2/165(1.2%) respectively whiles 11/165 (6.7%) were resistant to both drugs. Majority 42/120 (35%) of NTM were M. fortuitum. DST of 28 M. avium complex and 8 M. abscessus complex species revealed that all were susceptible to macrolides (clarithromycin, azithromycin) and aminoglycosides (kanamycin, amikacin, and gentamicin).ConclusionOur research signifies an important contribution to TB control in terms of knowledge of the types of mycobacterium species circulating and their drug resistance patterns in Ghana.Electronic supplementary materialThe online version of this article (10.1186/s12879-017-2853-3) contains supplementary material, which is available to authorized users.
This study was conducted to evaluate the effects of probiotic‐amended diets fed to juvenile Nile tilapia, Oreochromis niloticus, on growth and susceptibility to Streptococcus iniae infection. Fish (average weight 16.5 ± 0.2 g) were fed five diets formulated with Bacillus subtilis strains SB3086, SB3295, SB3615, or AP193 either individually or in combination of strains SB3086 and SB3615 at a targeted concentration of approximately 4 × 107 colony‐forming units (CFU)/g of feed or with a basal control diet with no additives for 21 d. After the 21‐d growth trial, no significant difference in growth performance was observed with any probiotic‐amended diet. Results from serum bactericidal activity showed a significant difference between treatments and the control (P = 0.0002), except for the SB3295‐amended diet (P = 0.9020). Lysozyme activity was also significantly different in fish fed probiotic diets from those fed control diet (P = 0.0001). After 21 d of feeding, fish were challenged with S. iniae by intraperitoneal injection at a dosage of 8 × 106 CFU per fish. Results from the challenge also showed a significant difference between treatments and control (P = 0.0001). Overall, fish fed with strain SB3615 showed the lowest percent mortality (44.0 ± 7.2%) and those fed the control diet showed the highest mortality (77.3 ± 7.0%). The combined feeding with strains SB3086 and SB3615 did not result in any significant difference in reducing mortality because of S. iniae infection in juvenile Nile tilapia when compared with the individual probiotic treatments.
This study was conducted to evaluate the individual and combined effects of long-term feeding of diets containing two probiotic Bacillus subtilis group strains (Aqua NZ and AP193) and the prebiotic Previda â , a commercial hemicellulose extract, on growth performance, immune parameters and Aeromonas hydrophila susceptibility of juvenile Nile tilapia, Oreochromis niloticus. Nile tilapia of average weight 7.47 AE 0.11 g were fed diets formulated with the probiotics and/or the prebiotic, or a control diet for 8 weeks and, subsequently, challenged with A. hydrophila by intragastric gavage at a dosage of 3.9 9 10 7 CFU per fish. Fish attained a mean weight of 59.5 AE 0.99 g at the end of the growth period. Under the conditions of the present trial, none of the diets significantly improved mean per cent weight gain (P = 0.70), thermal growth coefficient (P = 0.88) or feed conversion ratio (P = 0.87) of Nile tilapia. Except for the diet containing the prebiotic Previda â only (P = 0.17), all other diets resulted in significantly higher fish survival compared to the control (P < 0.05). The combined effect of the prebiotic and probiotic strains emerged as the most important diet with respect to mortality reduction. The mean lysozyme and respiratory burst activities did not show any significant differences between treatments and control (P = 0.14 and 0.32, respectively). Thus, these probiotic strains used in this study have the potential to prevent disease due to A. hydrophila in O. niloticus.
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