Microbiology Research Journal International

Background: Invasive aspergillosis (IA) is a leading cause of death among immunocompromised patients, particularly those with hematological malignancies. The use of galactomannan (GM) antigen as a biological marker for screening of IA in high-risk patients is attractive and non-invasive tool that detect evidence of IA prior to the appearance of clinical manifestations.

Objectives: The aim of this study was to compare the diagnostic value of the conventional blood culture technique to the serological detection of GM antigen using ELISA for screening of IA in neutropenic patients with hematological malignancies.

Methods: Forty patients with haematological malignancies from those admitted to the Clinical Oncology Department of Menoufia University Hospitals (MUH) were enrolled and classified to have either proven (5/40; 12.5%), probable (10/40; 25%) or possible (25/40; 62.5%) invasive aspergillosis based on the clinical criteria provided by the European Organization for research and treatment of Cancer (EORTC) and Mycoses Study Group (MSG). Blood samples were collected from all participants and subjected to conventional blood culture for isolation and identification of Aspergillus spp. ELISA technique was applied for serological detection of GM antigen in the patients’ serum samples.

Results: The sensitivity, specificity, PPV(positive predictive value)  and NPV (negative predictive value of GM antigen ELISA testing were 100%, 74%, 36% and 100% respectively for both proven and probable cases. On applying the principle of test in series (the patient is positive if positive in both culture and the GM test), the results were improved to 100% sensitivity, 100% specificity, 100% PPV, 100% NPV and 100% accuracy. Galactomannan antigen testing proved excellent sensitivity (80%) compared to other clinical features and radiological criteria for diagnosis of probable aspergillosis and proved to be a good negative test.

Conclusion: With conjunction of clinical and radiological signs, Aspergillus GM test can assist physicians in the of diagnosis of IA in patients with hematological malignancies to allow initiation of effective antifungal therapy which is ultimately important in high-risk populations.

Background: Urinary tract infection (UTI) in pregnancy is associated with significant morbidity for both the mother and the baby. Proper investigation and prompt treatment are needed to prevent the serious life-threatening condition and morbidity associated with UTI in pregnant women.

Aim: This study was designed to detect common uropathogens and their antibiotic susceptibility pattern among asymptomatic pregnant women attending antenatal care in the Bolgatanga Regional Hospital.

Methodology: Mid-stream urine samples were collected from 200 individuals and inoculated onto cysteine lactose electrolyte deficient (CLED) agar media.  Colony counts yielding bacterial growth of ≥ 10⁵ CFU /ml was regarded as significant bacteriuria. Pure isolates of bacterial pathogens were characterized by colony morphology, Gram-stain and standard biochemical procedures. Kirby Bauer disc diffusion method was used for antimicrobial susceptibility testing of all identified isolates.

Results: The overall prevalence of bacteria-associated asymptomatic UTI was 17.5%. Escherichia coli (42.9%) was the most isolated organism followed by Staphylococcus aureus (34.3%), Klebsiella pneumoniae (11.4%), Staphylococcus saprophyticoccus (5.7%) and Proteus mirabilis 2 (5.7%). Yeast cells and Schistosoma haematobium were also recorded in 2% of the women. Isolates showed significant sensitivity to commercially prepared antibiotic discs. However, higher level of resistance was recorded with tetracycline, nitrofurantoin and nalidixic acid.

Conclusion: Early screening for UTI should be done for all pregnant women and those found to be infected need to be treated with appropriate antimicrobial agents to avoid complications.

Ethanol production by S. cerevisiae was carried out using rice straw as substrate and B. subtilis and T. viride as hydrolyzing agents. The aim of this research is to compare the potential of rice straw (non-edible waste material) for bioethanol production using Bacillus subtilis and Trichoderma viride as cellulose hydrolyzing agents. The sample was dried and ground; and was subjected to chemical pretreatment and microbial hydrolysis to maximize sugar production. Standard methods were used to carry out isolation, identification and analysis of sample which includes proximate, mineral and physicochemical analysis. The sample was fermented for seven days during which ethanol yield was determined. Cellulose hydrolysis screening carried out on each of the two organisms revealed T. viride having the higher clearance zone of 1.8 cm, while B. subtilis had 1.5 cm. Proximate analysis obtained from the samples showed that the pretreatment method was relatively effective giving an increase in the cellulose and decrease in the hemicellulose and lignin contents of the samples. This showed rice straw having a cellulose content of 51.33 ± 0.17% after pretreatment. Potassium content was relatively high (17.96 mg/g), Hydrolysis using T. viride gave higher reducing sugar yield than that obtained using B. subtilis with 26.6 g and 12.21 g respectively. The pH was observed to decrease during fermentation while total titratable acidity observed showed an increase. Highest ethanol yield of 16.21 g/100 g was obtained using T. viride as hydrolyzing agent.

Aim: This study aimed to evaluate the antibacterial and antitubercular activities of ethylacetate and ethanol leaf extracts of Senna occidentalis.

Study Design: Fresh leaves of Senna occidentalis collected from Suleja, Niger state were used for this study against some medically important micro-organisms viz; Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella paratyphi, Klebsiella pneumoniae, Mycobacterium bovis and Mycobacterium smegmatis.

Place and Duration of Study: The study was conducted in Abuja, Nigeria at the Department of Microbiology and Biotechnology, National Institute for Pharmaceutical Research and Development [NIPRD], from February 2019 to April 2019.

Methodology: Senna occidentalis leaves were extracted successively with ethyl-acetate and ethanol. The obtained extracts were tested in vitro for antibacterial activity by agar well diffusion method, while anti-tubercular screening was carried out by broth micro-dilution method. A fixed-dose concentration of chloramphenicol was used as a control drug against the bacterial isolates while isoniazid was used as control drug against the mycobacterium isolates.

Results: The in vitro antibacterial screening showed that the crude extracts exhibited varying activity against the different microbes with highest zone of inhibition at 12 mm, and anti-tubercular activity with MICs ranging from 97.6-390.6 μg/mL.  Among these extracts, ethyl-acetate extract showed significant antibacterial activity against most of the test micro-organisms. The most susceptible micro-organism was P. aeruginosa (12mm zone in ethyl-acetate at 80 mg/mL) followed by B. subtilis (10 mm zone in ethyl-acetate extract at 80 mg/mL) and E. coli (9 mm zone in ethyl-acetate extract at 80 mg/mL). The ethanol extract was the most effective in inhibiting the growth of M. smegmatis and M. bovis with MICs of 97.6 μg/mL and 195.3 μg/mL.

Conclusion: The activities observed could be attributed to the presence of some active metabolites contained in the extracts which could be useful in drug development for therapeutic purposes.

Garlic (Allium sativum) contains various biologically active components that play a significant role in the treatment of bacterial and fungal infections. It contains sulfur compounds like allicin, ajoene, allylmethyltrisulfide, diallyltrisulfide, diallyldisulphide and others which exhibit various biological properties like antimicrobial, anticancer, antioxidant, immunomodulatory, anti-inflammatory, hypoglycemic and cardiovascular effects. The objective of the current review was to relate various literatures and assess the anti-microbial potential of garlic extract. The antimicrobial potency of garlic can be maximised by increasing the concentration of the extract. Garlic extract of 100% concentration showed a maximum zone of inhibition against both gram-positive and gram-negative bacteria.