Phenotypic characterization of mycobacteria isolates from tuberculosis patients in Kaduna State, Nigeria

Background: Tuberculosis (TB) remains one of the leading public health challenges in Nigeria and the burden is still high. There is hence a need for continuous characterization of mycobacteria to obtain current data that will aid the ongoing TB prevention and control programme. The aim of this study was to phenotypically characterize mycobacteria isolates recovered from clinical specimens of patients with tuberculosis in Kaduna State, Nigeria. Methods: Two thousand, two hundred and twelve (2212) sputum samples were collected from patients clinically suspected to have TB in three different zones of Kaduna State, Nigeria, between May 2017 and October, 2018. Samples were processed by decontaminating with NaOH-Citrate N-acetyl-L-Cystein method for Ziehl Neelsen (ZN) AFB microscopy and culture on Lowenstein Jensen (LJ) slants which were incubated at 37ᵒC for 8 weeks. Positive LJ cultures were further analyzed with a rapid TB antigen assay (SD-Bioline) to differentiate Mycobacterium tuberculosis complex (MTBC) from Non Tuberculous Mycobacteria (NTM). Results: Out of the 2212 patients with suspected TB, 300 (13.6%) were positive for AFB by microscopy with Zone A (Kaduna North) having the highest AFB positive cases of 169 (15.2%). Of the 300 AFB positive samples, 272 (91.0%) were culture positive on LJ medium, 18 (6.0%) were culture negative and 10 (3.0%) were culture contaminated. Result of the distribution of mycobacteria among infected patients within the study area revealed that 219 (80.5%) were infected with MTBC, 42 (15.4%) with NTM and 11 (4.0%) with both MTBC and NTM. Conclusion: A relatively high number of TB in the study area was caused by NTM. There is need for advanced diagnostic tools that can differentiate MTBC and NTM strains among TB patients in all TB Reference Laboratories in Nigeria

Molecular Characterization and Phylogenetic Analysis of Listeria monocytogenes Isolated from Milk and Milk Products in Kaduna, Nigeria.

In this study, Listeria (L.) monocytogenes isolated from milk and milk products in Kaduna, Nigeria, were subjected to a multiplex PCR assay to identify virulence-associated genes (such as prf A, inl A, hly A, act A, and iap). Of the 36 isolates, 9 (25%) were positive for one or two virulence-associated genes. Based on the sample type, 6 (16.9%) of the isolates that possessed virulence-associated genes were obtained from raw milk, 2 (3.2%) from "Manshanu," and 1 (2.8%) from "Kindrimo." Sequence and phylogenetic analysis based on the 16S rRNA revealed that Nigerian L. monocytogenes isolates (NGA 34A, NGA 35A, NGA 41A, and NGA 38A), when compared with reference L. monocytogenes, were grouped into two distinct clusters, A and B, with sequence (NGA 34A, NGA 35A, and NGA 41A) phylogenetically closer to J1776; N1-011A; R2-502; J1816; and J2-031, whereas L. monocytogenes isolate (NGA 38A) clustered with EDG; J1-220; J1926; J1817; and J2-1091. The separation of the Nigerian L. monocytogenes isolates into linage A (responsible for epidemic listeriosis) and lineage B (responsible for sporadic cases of listeriosis) is of public health concern and that local isolates might have potentials for human food borne listeriosis based on the virulence factors so far identified.

Production of extended spectrum beta-lactamases of urinary isolates of Escherichia coli and Klesiella pneumoniae in Ahmadu Bello University Teaching Hospital; Zaria; Nigeria

Multidrug resistant strains of Klebsiella pneumoniae and Escherichia coli constitute a problem in many hospitals. The antibiotic susceptibility profile and the Production of Extended Spetrum Beta-Lactamase (ESBL) of the strains of Klebsiella pneumoniae and Escherichia coli were assessed by the Kirby-Bauer technique and the modified disc diffusion technique respectively. Out of a total of 65 urinary specimens submitted to the Medical Microbiology laboratory at the Ahmadu Bello University Teaching Hospital; Shika-Zaria; Nigeria; 50 isolates consisting of 33 (66) Escherichia coli and 17 (34) strains of Klebsiella pneumoniae were recovered from patients suspected to have Urinary Tract Infections (UTIs). Of these 50 isolates; 15(30) were ESBL producers; made up of 6/17 (35.3) ESBL-positive Klebsiella pneumoniae isolates and 9/33 (27.3) ESBL-positive E. coli isolates. The susceptibility of the ESBL-positive Klebsiella pneumoniae isolates to ciprofloxacin; ofloxacin and amikacin were 64.7; 82.4 and 82.4 respectively; while the susceptibility of the ESBL-positive E. coli isolates were: ciprofloxacin (57.6); ofloxacin (48.5) and amikacin (84.8). All (100) of the ESBL-positive E. coli isolates and 3/6 (50) of the ESBL-positive Klebsiella pneumoniae isolates had Multiple Antibiotic Resistance (MAR) index of greater than 0.3 which is an indication that they originated from an environment where antibiotics are frequently used. It is important to determine the prevalence and antibiotic susceptibility of ESBL-producing clinical isolates as a guide to clinicians for the chemotherapy and there should be effective infection control policies to curb their spread in the hospital setting

A comparison of antibiotic resistance in microorganisms isolated from chicken and ostrich faeces in Bulawayo; Zimbabwe

Samples of fresh faeces were obtained from a free-range chicken source; three commercial chicken farms and a commercial ostrich farm; all located around Bulawayo City; Zimbabwe; in order to determine the antibiotic resistance profile of selected bacterial isolates of interest in food-related human infections. Samples were prepared at various dilutions and plated on selective media for Coryneforms; Escherichia coli; Enterococcus faecalis and Pseudomonas. The targeted bacteria were isolated as pure cultures and tested for antibiotic resistance to ampicillin; chloramphenicol; oxytetracycline; sulphonamide; streptomycin and tetracycline. Isolates from the faeces of chickens and ostriches in the commercial farms were found to be generally more resistant to streptomycin; tetracycline and oxytetracycline as compared to those from the free- range chickens. This study emphasizes the need to monitor antibiotic resistance genes in the environment and to curb/curtail antibiotic use for growth promotion in farm animals; particularly in developing countries; as continued use will only add to the growing problem of microbial antibiotic resistance

Fungal spores in the homes of asthmatic patients in Zaria, Nigeria.

The homes of asthmatic patients and nonasthmatic control group who worked on or lived near an irrigated farm were sampled over a 3-month period. Of a total of 21 genera isolated, 17 were from the indoor air in the patients' homes, 10 from the homes of the control group, and 18 from the air over the farm. Penicillium and Aspergillus species were dominant in the indoor spora while Gliocladium and Curvularia species were most common on the farm. There was significant correlation between the airborne genera encountered in the homes of patients and the farm sites.