In vitro Antiviral Activity of Nauclea latifolia Root Bark Extract Against the Respiratory Syncytial Virus

Extract of Nauclea latifolia (NL) root bark collected from the Nigerian flora was examined for anti-RSV activity. Preliminary data showed anti-RSV activities with IC50 =75.62 µg/ml when tested against the recombinant strain rgRSV expressing the green fluorescent protein. Corresponding assays for the cytotoxic effect of the extract against utilized cell lines gave TC50 = 333.82 µg/ml. Further screening of against the circulating RSV A2 strain established their promising anti-RSV utility. Time of additional studies for the elucidation of the possible mechanism of action gave 74.38, 69.42, and 71.90% reduction of RSV plaque forming units at the respective 0, 2, and 4 hours post-infection addition times.

First detection of FOX-1 AmpC beta-lactamase gene expression among Escherichia coli isolated from abattoir samples in Abakaliki, Nigeria

Objectives: Gram-negative bacteria represent the most relevant reservoir of resistance to antibiotics in the environment. The natural selection of resistant clones of bacteria in the environment by antimicrobial selective pressure is a relevant mechanism for spreading antibiotic resistance traits in both the community and hospital environment. This is in scenarios where antimicrobials are used irrationally, and even in the propagation of livestock, poultry birds, and for other veterinary purposes. This study sought to detect the prevalence of FOX-1 AmpC beta-lactamase genes from abattoir samples

Methods: The isolation of Escherichia coli, antimicrobial susceptibility testing, and beta-lactamase characterization was carried out using standard microbiology techniques. The production of AmpC beta-lactamase was phenotypically carried out using the cefoxitin-cloxacillin double-disk synergy test [CC-DDST], and FOX-1 AmpC genes was detected in the E. coli isolates using multiplex polymerase chain reaction

Results: Forty-eight E. coli isolates were recovered from the anal swabs of cows and 35 [72.9%] isolates were positive for the production of beta-lactamase. Notably, high percentages of resistance to cefoxitin [91.7%], ceftriaxone [83.3%], imipenem [85.4%], ceftazidime [87.5%], ofloxacin [81.3%], and gentamicin [85.4%] were found. FOX-1 genes were detected in three [6.3%] of the 48 E. coli isolates phenotypically screened for AmpC enzyme production

Conclusions: Abattoirs could represent a major reservoir of resistance genes especially AmpC beta-lactamase, and this could serve as a route for the dissemination of multidrug-resistant bacteria in the community. Thus, the molecular identification of drug-resistant genes is vital for a reliable epidemiological investigation and the forestalling of the emergence and spread of these organisms through the food chain in this region

Safety evaluation in mice of the childhood immunization vaccines from two south-eastern states of Nigeria

Objective: To check the effects of the vaccines on the hematopoietic system and weight of mice after immunization. Methods: The study was done with the Expanded Programme on Immunization vaccines donated by the Ministries of Health of Abia and Imo States of Nigeria. The vaccines were collected from the cold-chain stores and transported in vaccine carriers to the cold-chain facility in Nnamdi Azikiwe University Teaching Hospital within 3 hours of collection. They were used to immunize a total of 160 mice. The Ethics Committee of Nnamdi Azikiwe University Teaching Hospital, Nnewi of Anambra State, Nigeria approved the protocol. Results: Mice body weight changes test showed that the mice all had increased body weight at Days 3 and 7 post-immunization and none died during the 7 d post-immunization observation. The percentage weight gains of the mice compared with the control were 69%, 70%, 64%, 63%, 65% and 68% for oral polio vaccine, diphtheria-pertussis-tetanus, bacillus Calmette- Guérin, measles, yellow fever and hepatitis B vaccines respectively collected from Imo State. The mice immunized with oral polio vaccine, pentavalent, bacillus Calmette-Guérin, measles, yellow fever and hepatitis B vaccines collected from Abia State had 123%, 114%, 121%, 116%, 142% and 119% weight gain respectively compared with the control. Leukocytosis promoting toxicity test showed that none of the vaccines was able to induce proliferation of leukocytes up to ten folds. Leukopenic toxicity test showed that all the vaccines had an leukopenic toxicity test value higher than 80% of the control (physiological saline). Conclusions: The vaccine samples tested were safe and did not affect the hematopoietic system adversely. The storage conditions of the vaccines in the States' cold-chain stores had not compromised the safety of the vaccines.

Antimicrobial Activity of Selected Medicinal Plants of South-Eastern Nigeria on Pseudomonas species Expressing Extended Spectrum Beta Lactamase (ESBL).

Aim: To evaluate the antibacterial activity of selected medicinal plants from South- Eastern Nigeria against ESBL producing Pseudomonas species. Study Design: Agar well diffusion assay for determination of sensitivity and Agar dilution method for determination of MIC were used. Place and Duration of Study: Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, Nnamdi Azikiwe University, Awka, Anambra State, an Igbo speaking South-Eastern State in Nigeria, between February 2010 and october 2010. Methods: The antibiograms of ten (10) ESBL producing Pseudomonas species to selected antibiotics as well as the antibiograms of these isolates against methanol leaf extracts of Anthocleista djalonensis A Chev. (Loganiaceae) (MLEA) (Igbo name- Uvuru or Ayuu), Zapoteca portoricensis H. M. Hem. (Fabeceae/mimosidea) (MLEZ) (Igbo name- Ayuu), Gongrenema latifolium Benth. (Asclepiadaceae) (MLEG) (Igbo name- Utazi) and Psidium guajava Linn. (Myrtaceae) (MLEP) (Igbo name- Gova), using doses of 3000.00 to 21.87 mg/ml using agar disk diffusion and agar well diffusion assays respectively were determined. The MIC of the plant extracts in comparison with that of gentamicin were also evaluated using the agar dilution method. Results: All the ESBL producing Pseudomonas spp. were multi-drug resistant (IZD = 0) but, were all sensitive to imipenem. Only two strains of Pseudomonas monteilli were sensitive to MLEG with sensitivity decreasing with increasing concentrations of the MLEG. All the ESBL producing Pseudomonas spp were sensitive to MLEZ and MLEP. Also, sensitivity decreased with increasing concentration of the MLEZ and MLEP. MLEA showed no antimicrobial activity against the tested ESBL producing Pseudomonas spp. Gentamicin, with an MIC of 0.00015 μg/ml, was more active than the plant extracts. The MLEP was the more active with an MIC of 1 - 4.37 mg/ml, than MLEZ and MLEG which had MICs of 150 and 75 mg/ml respectively. Active constituents of these plant extracts especially that of Psidium guajava, may thwart the emerging resistance to carbapenems. Conclusion: Development of a complex mixture of the active constituents or single active constituent(s) of Psidium guajava as antimicrobial agent(s) that will be effective against ESBL producing Pseudomonas species.