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IntroductionIn spite of significant risks, as well as non-clinical importance due to loss of potency, stiff penalties against administration of expired medications are still not appropriately enforced by health policy makers in many developing countries, possibly because of little evidence to support that expired medications are hazardous. The purpose of this study therefore, was to investigate the effect of expiration dates on in vitro bacteriostatic potentials of oral paediatric antibiotics.MethodsComparative bacteriostatic potentials of 31 expired and seven corresponding unexpired oral paediatric antibiotics were determined on infantile diarrhoeagenic bacteria, using a modification of agar well-diffusion method.ResultsVerall total percentage in vitro resistance rates against expired and unexpired paediatric antibiotics respectively were - E. coli (≤100% vs. ≤15.9%), Klebsiella pneumoniae (≤100% vs. ≤31.3%), Proteus mirabilis (≤91.7% vs. ≤41.7%) and Staphylococcus aureus (≤100% vs. ≤18.2%). Resistance rates of 45.5-55.8% (sulfamethoxazole + trimethoprim 5), 39.5-63.6% (amoxycillin 6), 46.5-54.5% (cotrimoxazole 7), 37.5-63.6% (ampicillin + cloxacillin 18), and higher resistance rates of ≥75.0-100% were exhibited towards remaining expired antibiotics. Higher total resistance and multiple antibiotic resistance (MAR) rates were also recorded against expired antibiotics (45.2-93.5%) compared to unexpired antibiotics (28.6-57.2%), except for few strains of E. coli and Proteus mirabilis. Furthermore, unexpired paediatric antibiotics exhibited wider zones of inhibition towards the test diarrhoeagenic bacteria (≥25.0 mm diameter).ConclusionThis study provided preliminary microbiological results on the appreciable reduction in in vitro bacteriostatic potentials, as well as higher resistance and multiple antibiotic resistance rates among expired oral paediatric antibiotics on infantile diarrhoeagenic bacteria. Apart from less-efficacy, administration of expired antibiotics can lead to increased antibiotic resistance and clinical treatment failure, as well as adverse drug reactions.

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The use of microbial metabolites by interfacial tension reduction and wettability alteration mechanisms, for improved oil recovery from oil reservoirs, especially in mature oil fields have always been advocated for as a cheaper and environmentally-safe method of increasing oil production. Although microbial enhanced oil recovery (MEOR) in some advanced nations have come close to commercial applications, Nigeria is yet to venture into the microbial enhancement of oil recovery. Nigeria as a nation has had its fair share of the global dilemma of decreased oil production caused by unrecovered oil in oil reserves, resulting in adverse effects on its economy energy status. Uncertainties on the efficiency of MEOR in practical reservoirs, failure of petroleum engineers and scientists to form multidisciplinary teams, and lack of adequate understanding of MEOR processes are some factors that have slowed down the process of adopting MEOR as an alternative to other enhanced oil recovery methods in Nigeria. Other significant factors include, lack of appropriate microbial mechanisms for the success of MEOR applications; various in situ and ex situ laboratory and field trials experiments on effectiveness of high-strength biosurfactants, in microbial enhanced oil recovery, best interfacial tension reduction and wettability alteration mechanisms, novel sets of core flooding tests, with potential indigenous and control microbial consortium, for optimal oil recovery efficiency; adsorption of microbial cells and biofilm formation for inductive MEOR, towards wettability alteration of reservoir rock for production of neutrally wet condition, for the improvement of oil recovery efficiency; modified advantageous quorum-sensing and behavioural diversity of potential MEOR-applicable microbes, as well as, genetic modification of selected safe and environmental-friendly candidates. In addition to economic, health and environmental issues that still linger, and call for urgent attention, a general overview of microbial enhanced oil recovery in Nigeria comprising of the mechanisms of oil recovery by MEOR, factors hindering its implementation in Nigeria and the need for MEOR laboratory and field trials to be performed in order to determine the viability of the process in Nigeria is pertinent in order to provide a lasting solution to decreasing oil production.

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Background and Aim: The aim of this study was to conduct in vitro and in vivo studies for the evaluation of antimicrobial potential of four Nigerian indigenous chewing sticks and to compare the oral effects of the popular Nigerian chewing sticks with toothpastes and other teeth-cleansing agents on a total of 21 and 17 oral bacterial strains isolated from children and adult dental caries respectively. Materials and Methods: Teeth cleansing agents were assayed in vitro against the isolated bacterial carries flora on de Man Rogosa and Sharpe (MRS) agar using modified agar well-diffusion methods. The simulated in vivo studies were carried out using twenty four human subjects. Results: The results obtained indicated that the bacterial flora exhibited different degrees of in vitro inhibitions of between low and moderate susceptibility against the teeth-cleansing agents. Toothpastes recorded the highest rates of inhibition against the dental caries isolates, while H2O2 was the most inhibitory among the chemical teethcleansing agents against the dental caries isolates from children (47.6%) and adults (52.9%). No species differential susceptibility to the teeth-cleansing agents was observed among the dental caries isolates. Conclusions: This study showed that combined teeth cleansing hygiene with toothpastes, chewing sticks and chemical teeth cleansing agent (H2O2) gave the best mouth feel and were found to be the most preferred.

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Objective:This study aimed at evaluating the in vitro efficacy and health implications of inconsistencies in different production batches of antimycotic drugs.Materials and Methods:in vitro susceptibility profiles of 36 Candida spp. – C. albicans (19.4%), C. glabrata (30.6%), C. tropicalis (33.3%), and C. pseudotropicalis (16.7%) – obtained from human endocervical and high vaginal swabs (ECS/HVS) to two different batches (B1 and B2) of six antimycotic drugs (clotrimazole, doxycycline, iconazole, itraconazole, metronidazole and nystatin) was determined using modified agar well-diffusion method.Results:None of the Candida strains had entirely the same (100%) susceptibility / resistance profiles in both batches of corresponding antimycotic drugs; while, different multiple antifungal susceptibility (MAS) rates were also recorded in batches 1 and 2 for corresponding antifungals. Only 14.3%, 27.3%, 16.7-33.3%, and 8.3-25.0% of C. albicans, C. glabrata, C. pseudotropicalis, and C. tropicalis strains, respectively, had similar susceptibility/resistance profiles toward coressponding antifungal agents in both batches; while up to 57.1% of C. albicans, 45.5% of C. glabrata, 66.7% of C. pseudotropicalis, and 50.0% of C. tropicalis strains were susceptible to one batch of antifungals but resistant to corresponding antifungals in the second batch. As high as 71.4% (C. albicans), 73.0% (C. glabrata), 50.0% (C. pseudotropicalis), and 66.74% (C. tropicalis) strains had differences of ≥ 10.0 mm among corresponding antimycotic agents.Conclusions:Candida strains exhibited different in vitro susceptibility / resistance patterns toward two batches of corresponding antimycotic agents, which has clinical implications on the efficacy of the drugs and treatment of patients. The findings of the present study will be of benefit in providing additional information in support of submission of drugs for registration to appropriate regulatory agencies.