South Asian Journal of Research in Microbiology

Aim: HIV/AIDS continues to spread globally and remains a worldwide pandemic. Opportunistic infections (OIs) occur more and are severe in people living with HIV who have weakened immune systems, and co-infection is another major challenge because it affects the rate to which the disease progress to AIDS. In the present study, a total of 100 HIV positive patients were recruited and evaluated for the presence of common opportunistic infections (OIs) and co-infections among HIV-infected individuals in Port Harcourt, Nigeria.

Study Design: Cross-sectional study.

Place and Duration of Study: Prime Medical Consultants in Port Harcourt, Nigeria, between June 2012 and July 2015.

Methods: A total of 100 HIV-infected individuals were recruited for this study (ages 1 to 70 years, 62 males and 38 females). Samples of blood, sputum, high vaginal swabs (HVS) and scrapped lesion from the mouth of the patients were collected. Blood samples were re-screened for the presence of HIV antibodies and HBsAg using the Determine HIV-1/2 (Alere), HIV ½ Stat-Pak (Chembio), HIV-1/2/P24/O ELISA kit and HBsAg one Ultra ELISA kit (Dia.Pro) following the respective manufacturer's instructions. The Ziehl-Neelsen sputum smear microscopy method was used for identifying tuberculosis (TB). Microscopical examination was done on HVS samples and lesions scrapings from the mouth to observe for Candida. Chi-square test was used to establish relationships between demographic factors and prevalence, and significance level was set at P ≤ 0.05.

Results: Of the 100 HIV positive patients, suspected case were 32.0% of TB, 28.0% of oral thrush and vaginosis, and 19.0% of hepatitis. The results of the laboratory analysis further showed that tuberculosis was the most common OI among others. Overall prevalence was 22.0% for TB, 11.0% for Candida albicans (oral thrush), 28.9% for Candida albicans (vaginosis) and 4.0% for HBV.  Higher prevalence of TB was observed in the age groups 41 years & above (35.7%, P=0.14) and in males (22.6%, P=0.86). As for Candida albicans, the higher prevalence was found in age groups 21-40 years (19.1%, P=0.03) and in females only (28.9%), and higher prevalence of HBV was found in age groups 41 years & above (9.1%, P=0.78) and in females (5.3%, P=0.61). None of the variables (age and sex) evaluated in this study was statistically associated (P>0.05) with TB, Candida and HBV prevalence.

Conclusion: The study has also shown that some opportunistic infections (candidiasis and Tuberculosis) and coinfections with HBV is prevalent among HIV infected individuals and this could largely be due to a compromised immune system as a result of the viral activities in the host cell. There is need therefore to routinely check for OIs and co-infections especially in the case of an immunocompromised individual. It is also imperative to note that the appropriate use of drugs against these OIs may be one of the strategies to extend the life span of AIDS patients. This will help to monitor how the disease progresses and its complications.

Chagas is a neglected disease, one of Brazil’s main medical and social problems and a serious public health problem in the Americas, with more recent occurrences in non-endemic countries outside of the Americas. Research into the microbiota of triatomines is relevant because of its potential role in vector competence and as a proposed biological control strategy. Stressing a possible insect-fungal interaction in the development of Trypanosoma cruzi, and considering the lack of studies on the subject, we analyzed the fungal microbiota of the digestive tract of two species considered important vectors of Trypanosoma cruzi: Triatoma infestans and Panstrongylus megistus. Specimens were dissected, digestive tracts macerated and contents serially diluted. Each aliquot was seeded in three culture media. The plates were incubated in type B.O.D. climate chambers for 21 days, after which isolated colonies were morphological characterized and identified. There have been few published studies on the fungal microbiota of the triatomine digestive tract. Comparing the results found here with existing data reveals that the genera Aspergillus and Penicillium are commonly found in the digestive tract of the studied triatomines. Among the several genera identified, the species found in the highest percentages were Aspergillus flavus, Paecilomyces variotii, Penicillium waksmanii, Penicillium raistrickii and Penicillium fellutanum. Quantitative differences in the number of isolated fungal strains were observed according to sex and nymphal stage of the vector. The present findings corroborate those found in the literature, showing that there is a natural fungal microbiota in triatomines. Data revealing quantitative differences in isolated fungal strains found in male, female and nymphs reinforce the idea that their presence is related to physiology and fasting resistance. The secondary metabolite-producing fungi isolated in this work have in their biology great potential to be tested with regard to the establishment of T. cruzi in the digestive tract of its vector.

Aim: The present study investigates the effect of phosphate-solubilizing bacteria (phosphobacteria (PB) and activity of soil bacteriostasis on the development of Azotobacter in Thymus vulgaris rhizosphere.

Place and Duration of Study: The study was conducted at Kenule Beeson Polytechnic botanical garden and at the Science Laboratory Department of the institution for a period of 7months (from March 2018- September 2018). 

Methods: The impact of phytohormones produced by phosphate-solubilizing bacteria in vitro and in the rhizosphere of T. vulgaris was used to assay for Azotobacter colonization. Bacteriostasis activity of the soil was determined by comparing the number of Azotobacter microcolonies on discs incubated over soil with respect to those on the controls.

Results: Decisive stimulation of Azotobacter population and establishment was observed in Thymus vulgaris rhizosphere when inoculated with phosphobacteria than when inoculated alone as reflected in 5% (0.05) least significant difference. Azotobacter was susceptible to the bacteriostatic factors in potted soils inoculated with it and without (Azotobacter). The increase in susceptibility of this rhizospheric bacteria was time dependent and reached a maximum and thereafter remained almost constant. However, this was overcome by the addition of NPK fertilizer to the plant at some critical stage of the assay.

Conclusion: The Presence of nitrogen fixing bacteria (NFB) in vegetation could play significant role in the sustainability and improvement of plant growth and yield. Soil bacteriostasis can also be an important factor that limits the survival and development of NFB.

Aim: Test the effect of Azadirachta indica fruit extract on seed-borne fungi and seed performance of different rice varieties.

Study Design: Neem fruits harvested in the locality of Pala in Chad were used to assess the antifungal effect on rice seeds. Samples of eight rice varieties (TOX, CH3, CH8, WITA9 D6, D4, D3 and D1) were collected in Bongor, Chad to assess their performance against the aqueous extract of neem fruits.

Place and Duration of Study: This study was carried out at the Research Unit of Phytopathology and Agricultural Zoology of the Faculty of Agronomy and Agricultural Sciences of the University of Dschang/Cameroon from June to October 2018.

Methodology: Rice seeds were dipped in Azadirachta indica extract at concentrations of T25 (25 mg/ml), T50 (50 mg/ml) and T75 (75 mg/ml) for 1 hour before being incubated in petri dishes containing blotting paper. Distilled water (T0) and mancozeb 80 WP (TMn1 mg/ml) were used as negative and positive controls respectively.

Results: The results showed that the germination rate from rice seeds treated with Azadirachta indica extract was better (97.14%) than the rate from the negative controls (82.53%). The infection rate of rice seedlings, the number of rotten seeds and the number of abnormal seedlings were significantly (P =.05) lower for Azadirachta indica extract treatments than for the negative control (T0).

Conclusions: Neem (Azadirachta indica) fruit extract has a bio-fungicidal potential and a bio-stimulator of rice seed germination. This extract of Azadirachta indica fruit can be used to improve rice cultivation.

Aims: The purpose of this study was to isolate and screen soil fungi that are able to tolerate the contents of spent deep cycle battery (inverter), and to test for their bioremediation potential.

Place and Duration of Study: Sample: Department of Microbiology, Rivers State University, between June 2019 and February 2020.

Methodology: Soil samples were collected from a mechanic village while spent inverter batteries were obtained from a waste vendor. The battery was forced open to extract its contents of the battery. Using standard microbiological techniques, fungi were enumerated and characterized. Stock solution of the battery content was prepared by dissolving the inverter battery content in sterile deionized water. This stock solution was used to carry out the screening test on the fungal isolates to ascertain the fungi that can tolerate the contents of the spent battery.

Results: Total heterotrophic fungal counts for the polluted and unpolluted soil were 6.0 x 10³ cfu/g and 7.5 x 10⁴cfu/g respectively. The fungal isolates identified from the polluted soil samples were members of the genera Rhizopus, Mucor, Aspergillus, Penicillium, and Candida, while, the isolates identified from the unpolluted soil sample includes: Candida sp, Aspergillus niger, Penicillium sp, Aspergillus fumigatus, Aspergillus flavus, Mucor sp, Yeast, Fusarium sp and Aspergillus sp. After the screening, total heterotrophic fungal counts for the soil ranged from 1.0 x 10²cfu/g to 9.5 x 10²cfu/g. Two fungi of the genera: Rhizopus and Mucor had the highest counts during 72 hours of incubation for the screening test. The results obtained from this study indicated that species of Aspergillus, Penicillium, and Candida were the most inhibited by the contents of the spent battery while Rhizopus and Mucor spp were more tolerant to the contents of the inverter. Rhizopus and Mucor spp were therefore, adopted in the bioremediation of soil contaminated with contents from the battery. It was observed that Rhizopus and Mucor spp in a consortium had the highest percentage of heavy metal removal (or uptake) in the following order: Cadmium (66.66%) > Lead (38.15%) > Zinc (26.83%) > Nickel (20.83).

Conclusion: These organisms can be used in the bioremediation of soil polluted with metals from spent deep cycle batteries.