Mycobacterium senegalense from bovines in Eastern Nigeria

Detailed characteristics of three mycobacterial strains sharing important properties of Mycobacterium senegalense are described. Their physiological properties were compared with those of a typical M. senegalense strain described by Chamoiseau (1979), six strains of M. senegalense and one typical strain of M. fortuitum from the culture collection of Institute of Microbiology, Rutgers. The three Nigerian strains exhibited minor variations in their physiological properties when compared with other strains of M. senegalense. Unlike the strain of Chamoiseau the Nigerian strains did not utilize benzoate or citrate. The strains were also different from the other six strains of M. senegalense by utilizing trehalose and in failing to produce acid in mannitol. Unlike earlier isolates of M. senegalense the Nigerian strains were not from cases of bovine farcy but from cases with pathological manifestations of pulmonary tuberculosis. They appeared to be intermediate strains between M. senegalense and M. fortuitum. These results raise doubts on the justification for giving specific rank to M. senegalense.     

Equivalence of mycobactins from Mycobacterium senegalense, Mycobacterium farcinogenes and Mycobacterium fortuitum

Mycobactins were isolated from five strains designated Mycobacterium farcinogenes and a similar number designated Mycobacterium senegalense following growth under conditions of iron-limitation. These lipid-soluble iron-chelating compounds were characterized by a combination of thin-layer and high-performance liquid chromatography. The mycobactins from both the slow-growing M. farcinogenes and the rapidly-growing M. senegalense strains proved impossible to differentiate both from each other and from those produced by strains of Mycobacterium fortuitum, indicating a close relationship between all three species. However, Nocardia farcinica, previously implicated with the bovine farcy strains, produced a different mycobactin which was easily distinguished by thin-layer chromatography alone.     

Classification of Mycobacterium farcinogenes and Mycobacterium senegalense by immunodiffusion and thin-layer chromatography of long-chain components

Comparative immunodiffusion studies and thin-layer chromatographic analyses of whole-organism acid methanolysates were performed on 37 strains of Mycobacterium farcinogenes, Mycobacterium senegalense and Nocardia farcinica. The latter were clearly distinguished from the mycobacteria in containing a single mycolic acid methyl ester and showing more precipitinogens with nocardial than with mycobacterial and rhodococcal reference systems. The distribution of precipitinogens showed that M. farcinogenes and M. senegalense were very closely related and that both showed a greater affinity to Mycobacterium fortuitum than to any of the other established species of Mycobacterium tested. The complex pattern of alpha-mycolates and characteristic polar mycolates found in both M. farcinogenes and M. senegalense has only previously been found in M. fortuitum and Mycobacterium smegmatis.     

Non-surgical recovery of eggs from single-ovulating bovines

Egg recovery was attempted by non-surgical technique 128 times from 38 single-ovulating cows and heifers 7 or 8 days after insemination. Ninety-one (71%) eggs were recovered of which 81 (89%) were fertilized.     

Epidemiology of dermatophytoses in a rural community in Eastern Nigeria and review of literature from Africa

A total of 4,287 primary school children, comprising 1,740 males and 2,547 females in Arochukwu local government area of Abia state Nigeria were examined for clinical signs of dermatophytoses. About 873 (20.4%), consisting of 505 males and 368 females had lesions consistent with dermatophytoses. The disease was more prevalent in males (29%) than females (14.4%) in a ratio of approximately 2:1 (P < 0.05). The infection rate increased from 16.8% in the 4–6 year age group to a peak of 28.1% in the 10–12 year age bracket and dropped sharply to 5.6% in the 16–18 year group. The highest prevalence (39%) was observed among males aged 10–12 years while females 16–18 years had the lowest prevalence (2.5%). Tinea capitis was the predominant clinical type of dermatophytoses, and occurred in 13.7% of the total population studied and 67% of lesion positive cases. Trichophyton soudanense and Trichophyton tonsurans the predominant aetiological agents of dermatophytoses with a prevalence of 26.2% and 21.6%, respectively. Others include Trichophyton mentagrophytes (18.8%), Epidermophyton floccosum (8.3%), Microsporum audouinii (6.4%), Microsporum gypseum (6.0%), Trichophyton rubrum (5.5%) and Microsporum ferrugineum (7.3%), which was isolated for the first time in Nigeria.     

Some deep mycoses diagnosed by histopathology in South Eastern Nigeria

Twenty-three cases of deep mycoses were histologically diagnosed in 6500 surgical biopsy specimens examined during a three year period (1985-1988) in the Department of Pathology, University of Calabar Teaching Hospital, Calabar, Nigeria. These included 12 cases of African histoplasmosis, four of mycetoma, four of actinomycetoma, two of paranasal aspergilloma, and one of zygomycosis due to Conidiobolus coronatus (rhinoentomophthoromycosis). Involvement of tooth gum and colon in one case each of African histoplasmosis, and of maxillary sinus in two cases of paranasal aspergilloma were unusual clinical manifestations. The need for greater awareness of deep mycoses and for provision of adequate laboratory facilities in Nigeria is emphasized.     

Sero-epidemiology of Neisseria meningitidis infections in parts of Eastern Nigeria.

The prevalence of antibodies to meningococci in the Nsukka area, East Central Nigeria, was studied by the indirect hemagglutination test employing tanned chicken erythrocytes. Of the 1332 apparently healthy persons, whose sera were tested, 982 samples (73.8%) were positive at 1:8 dilution of the sera. Fifty-six per cent of the population had antibodies to Group B, followed by 13% of Group C and 5% to Group A. Twenty-five sera from patients with meningococcal infections, from whom Group B meningococci were isolated, 100% were positive. Percentage reactivity in the 2-5-year age group was low (15%), whereas it increased rapidly from 78% (6-10-year group) to 95% (31 years and above).     

Detection and molecular characterization of 9,000-year-old Mycobacterium tuberculosis from a Neolithic settlement in the Eastern Mediterranean

Background

Mycobacterium tuberculosis is the principal etiologic agent of human tuberculosis. It has no environmental reservoir and is believed to have co-evolved with its host over millennia. This is supported by skeletal evidence of the disease in early humans, and inferred from M. tuberculosis genomic analysis. Direct examination of ancient human remains for M. tuberculosis biomarkers should aid our understanding of the nature of prehistoric tuberculosis and the host/pathogen relationship.

Methodology/Principal Findings

We used conventional PCR to examine bone samples with typical tuberculosis lesions from a woman and infant, who were buried together in the now submerged site of Atlit-Yam in the Eastern Mediterranean, dating from 9250-8160 years ago. Rigorous precautions were taken to prevent contamination, and independent centers were used to confirm authenticity of findings. DNA from five M tuberculosis genetic loci was detected and had characteristics consistent with extant genetic lineages. High performance liquid chromatography was used as an independent method of verification and it directly detected mycolic acid lipid biomarkers, specific for the M. tuberculosis complex.

Conclusions/Significance

Human tuberculosis was confirmed by morphological and molecular methods in a population living in one of the first villages with evidence of agriculture and animal domestication. The widespread use of animals was not a source of infection but may have supported a denser human population that facilitated transmission of the tubercle bacillus. The similarity of the M. tuberculosis genetic signature with those of today gives support to the theory of a long-term co-existence of host and pathogen.     

Epidemiology of Clinical Isolates of Mycobacterium tuberculosis at Ibadan, Nigeria

Despite the huge burden of tuberculosis (TB) in Nigeria, case detection rate of infectious cases still remain low, thus constituting obstacle to eradication of the disease in the community. We carried out a 15 month (1st January 2008 to 30th March 2009) retrospective review of epidemiology of clinical isolates of M. tuberculosis isolated at TB regional reference laboratory at the department of Medical Microbiology and Parasitology, University College Hospital, Ibadan, Nigeria. Fifty isolates were recovered from 720 specimens during the period of study with a recovery rate of 6.9%. Sixty- two (8.6%) of the specimens were contaminated. Thirty eight (76.0%) isolates were from the specimens of male subjects and 12 (24.0%) from female subjects giving a male to female ratio of 3.2: 1.0 Majority (62.0%) of the isolates were from subjects aged 20 years and above with an isolation rate of 7.3% while only two clinical isolates (4.0%) were recovered from specimens from children. A high yield of 20.8% was recovered from specimen collected from Hausa ethnic group who predominantly domiciled in a particular part of the metropolis. In terms of socio-economic status, clinical isolates recovered from specimens from unskilled workers (76.0%) was more than thrice from that obtained from the professionals (24.0%). Seven (14.0%) of the total isolates were recovered from extra-pulmonary lesions while the majority 43 (86.0%) were for pulmonary TB. The isolation rate from children and extra-pulmonary sites are low. This suggests a need to pay more attention to diagnosis of childhood and extra-pulmonary TB in Ibadan, Nigeria.Keywords: M. tuberculosis, Isolates, Epidemiology, Ibadan.     

Shigellosis in Eastern Nigeria: Etiological frequency of serotypes and resistance to antibiotics

Between 1984 and 1986 a total of 1000 faecal samples and rectal swabs were cultured from patients presenting with diarrhoea. Shigellae were isolated from 5·6% of these samples. Shigella flexneri was the commonest isolated (68%), followed by Sh. sonnei (23%). A total of 22·8% of children (0–12 years of age) were positive for shigellae. Twenty-seven (48·2%) strains were sensitive to all the five antibiotics tested (streptomycin, chloramphenicol, tetracycline, ampicillin and sulphonamide). A total of 22 (39·2%) were resistant to three or more antibiotics. Nine (16%) were resistant to all five. The public health significance of the study is discussed.     

Anandamide induces sperm release from oviductal epithelia through nitric oxide pathway in bovines

Mammalian spermatozoa are not able to fertilize an egg immediately upon ejaculation. They acquire this ability during their transit through the female genital tract in a process known as capacitation. The mammalian oviduct acts as a functional sperm reservoir providing a suitable environment that allows the maintenance of sperm fertilization competence until ovulation occurs. After ovulation, spermatozoa are gradually released from the oviductal reservoir in the caudal isthmus and ascend to the site of fertilization. Capacitating-related changes in sperm plasma membrane seem to be responsible for sperm release from oviductal epithelium. Anandamide is a lipid mediator that participates in the regulation of several female and male reproductive functions. Previously we have demonstrated that anandamide was capable to release spermatozoa from oviductal epithelia by induction of sperm capacitation in bovines. In the present work we studied whether anandamide might exert its effect by activating the nitric oxide (NO) pathway since this molecule has been described as a capacitating agent in spermatozoa from different species. First, we demonstrated that 1 μM NOC-18, a NO donor, and 10 mM L-Arginine, NO synthase substrate, induced the release of spermatozoa from the oviductal epithelia. Then, we observed that the anandamide effect on sperm oviduct interaction was reversed by the addition of 1 μM L-NAME, a NO synthase inhibitor, or 30 μg/ml Hemoglobin, a NO scavenger. We also demonstrated that the induction of bull sperm capacitation by nanomolar concentrations of R(+)-methanandamide or anandamide was inhibited by adding L-NAME or Hemoglobin. To study whether anandamide is able to produce NO, we measured this compound in both sperm and oviductal cells. We observed that anandamide increased the levels of NO in spermatozoa, but not in oviductal cells. These findings suggest that anandamide regulates the sperm release from oviductal epithelia probably by activating the NO pathway during sperm capacitation.     

Bayesian inference of population expansions in domestic bovines

The past population dynamics of four domestic and one wild species of bovine were estimated using Bayesian skyline plots, a coalescent Markov chain Monte Carlo method that does not require an assumed parametric model of demographic history. Four domestic species share a recent rapid population expansion not visible in the wild African buffalo (Syncerus caffer). The estimated timings of the expansions are consistent with the archaeological records of domestication.