Aflatoxin M1 Contamination of Milk and Its Products in Bomet County, Kenya

Aflatoxin M1 (AFM1) is a major carcinogenic compound that may be found in milk and dairy products resulting from ingestion of aflatoxin B1 by dairy animals. The study aimed at determining the level of aflatoxin M1 in milk and milk products from Bomet County. A total of 185 samples (150 raw milk and 35 processed milk and milk products) were randomly collected from milk collection sites and randomly selected milk kiosks respectively. The AFM1 was analyzed using a commercial ELISA kit (Ridascreen, aflatoxin M1 R-Biopharm, Product code, R5812, Darmstadt, Germany). Out of 185 samples investigated, 156 samples were positive for AFM1, an overall contamination rate of 84.32%. The samples with levels higher than the tolerance limit of 0.05 μg/l recommended by Food and Agriculture Organization (FAO) and World Health Organization (WHO) limits were 43.8% mainly contributed by the raw milk compared to processed milk (52.0% versus 8.6%). Processed milk had insignificant level of contamination with aflatoxin M1 (Median 0.00 (IQR: 0.00, 0.00 μg/l) with a minimum of 0.00 μg/l and a maximum of 0.69 μg/l. Raw milk showed significant contamination, median 0.09 (IQR: 0.00, 0.50) μg/l with a minimum of 0.00 μg/l and a maximum of 2.93 μg/l. Although there was no significant differences in AFM1 levels with study sites (P = 0.217);the median levels of aflatoxin M1 was high in sites 1, 3, and 7. The sites that had median aflatoxin M1 levels below the WHO/FAO acceptable limits of 0.05 μg/l were sites 2, 4 and 6. Due to high incidence of AFM1 contamination of milk and milk samples in Bomet County, there is need for regular monitoring and regulation of AFM1 contamination in milk and its products in the County.

Characterization and Antimicrobial Susceptibility of Actinomycetes from TB Smear Negative and Retreatment Patients in Nairobi, Kenya

Actinomycetes are opportunistic pathogens in immunosuppressive patients. Pulmonary actinomycetes infections display symptoms that mimic Mycobacteria tuberculosis and can be misdiagnosed and treated as pulmonary TB. Actinomycetes can be co-infection with tuberculosis leading to delayed or inappropriate treatment. This study aimed to identify and determine antimicrobial susceptibility profiles of Actinomycetes from the sputum of TB smear negative and re-treatment patients referred to TB reference facilities in Kenya. Sputum specimens were collected and direct smears stained with Gram’s reagents. Culture was done on Mueller Hinton agar and incubated at 35°C for two weeks. Identification was done using phenotypic and biochemical procedures. Confirmation of the isolates was done using Polymerase Chain Reaction. A total of 52/385 (14%) Actinomycetes were isolated and subjected to antimicrobial susceptibility testing using broth microdilution method to determine the Minimum Inhibitory Concentration. Nine antibiotics were tested which included: Amikacin, Amoxicillin/Clavulanic acid, Ceftriaxone, Ciprofloxacin, Clarithromycin, Linezolid, Doxycycline, Trimethoprim-Sulfamethoxazole and Gentamycin. Staphylococcus aureus (ATCC 25923) was used as a control. Most of the isolates were susceptible to the test antibiotics. However, four isolates showed multidrug resistance to Ceftriaxone and Clarithromycin with resistance of 11.5% and 26.9% respectively. Gentamycin and Ciprofloxacin showed the highest susceptibility of 100% and 98.1% respectively. The findings of this study confirm that Actinomycetes are significant pathogens in TB smear-negative cases. Although most antibiotics were susceptible, resistance to few antibiotics was observed;hence, there is a need for proper screening of TB smear-negative cases to detect infections by Actinomycetes and also conduct the antimicrobial susceptibility test to determine which antibiotic is effective.

Bio-Prospecting for Broad Spectrum Antibiotic Producing Actinomycetes Isolated from Virgin Soils in Kericho County, Kenya

Antimicrobial drug resistance is a rising concern in the treatment of infectious diseases and necessitates the need for discovery of novel, potent antimicrobial compounds to combat antibiotic resistance. Since natural environment remains a potential source of novel antimicrobial products, this preliminary study was performed to test the potential of soils from Kericho County for antibiotic-producing Actinomycetes. Soil samples (214) were randomly collected from virgin soils of Kipkelion East, Kipkelion West, Belgut, Ainamoi, Sigowet and Bureti sub-counties in Kericho County from a depth of between 11 cm - 16 cm from the surface of the soil profile. A total of 107 Actinomycetes were isolated and screening was done using modified agar disc diffusion method of which only 39 (36.4%) showed antimicrobial activity against five of the six test isolates that included reference strains Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922) and Candida albicans (ATCC 90028) and three clinical strains Trichophyton mentagrophyte, Microsporum gypseum and Methicillin Resistant Staphylococcus aureus. Two of the isolates showed activity against MRSA and four isolates showed a higher potency than the standard drug Chloramphenicol (30 μg) against S. aureus. Most of the isolates (41.0%) also showed good antimicrobial activity against T. mentagrophyte, though they lower than the control drug Itraconazole (2 μg/ml), they were statistically significant. DNA from the isolates was extracted and the 16S rRNA gene was amplified using primers specific for Actinomycetes. The amplified gene was sequenced and phylogeny analysis was done. The 16S rRNA gene was able to be amplified in only 15 of these isolates. Sequencing showed that 93.3% were of the genus Streptomyces while 6.7% were of the genus Rhodococcus. From the results, the soils from this region harbour Actinomycetes that may have good potential of producing novel antibiotics against gram positive bacteria and dermatophytes.

Spectrum of Filamentous Fungi from Sputum of Tuberculosis Relapse and Retreatment Patients in Tuberculosis Reference Facilities

Background: Fungal infections represent a significant cause of morbidity and mortality among immunocompromised individuals. Pulmonary fungal infection may be missed or misdiagnosed as tuberculosis (TB) hence complicating management of these patients. The current study reports the spectrum of filamentous fungi isolated from sputum of TB relapse and retreatment cases at selected reference facilities in Kenya. Methods: A total of 340 sputum samples collected during the period of June 2018 to June 2019 were subjected to mycological investigations. The samples were mucolysed and inoculated on sabourauds dextrose agar (SDA) and incubated at 30°C for 7 days and checked daily for fungal growth. Moulds were identified by macroscopic and microscopic morphological features and the species were confirmed by sequencing. Results: The diversity of fungi out of the 340 sputum samples analyzed was as follows;16% (n = 53) were positive for moulds with Aspergillus species being the predominant constituting 68 % (n = 36). Among the Aspergilli, A. flavus and A. niger were the most frequently isolated adding up to 23%, (n = 12) and 15% (n = 8) respectively. Additionally, Paecillomyces variotii (9%, n = 5), Scedosporium aspiospermum (6%, n = 3), Mucor racemosus (8%, n = 4) and Penicillium spp. (9%, n = 5) were also recovered. Conclusion: The isolated fungi represented potential respiratory pathogens that could be responsible for persistent TB like symptoms despite treatment that could be misdiagnosed as relapse requiring treatment. Fungal investigation of all presumptive TB relapse cases should be advocated before treatment. This will reduce unnecessary retreatment, delayed antifungal intervention and unwarranted morbidity and mortality associated with misdiagnosis.