Methicillin-Resistant Staphylococcus aureus (MRSA):An Emerging Phenomenon among non-Hospitalized Otorhinolaryngological Patients in Benin City, Nigeria.

BACKGROUND: Methicillin resistant Staphylococcus aureus (MRSA) was first detected in hospitals and one of the most common causes of nosocomial infections worldwide. There are reports that 50% of the infectious morbidity in intensive care units (ICUs) was due in part to MRSA. MRSA is also emerging in community. Community-associated MRSA is now the most common pathogen cultured from patients with skin and soft tissue infections in emergency departments. STUDY DESIGN: This study was conducted in otorhino-laryngology department of University of Benin Teaching Hospital, South-South region of Nigeria during the period July to September 2012. It was designed to provide baseline data on the emerging MRSA phenomena in surgical site infections. RESULTS: A total of one hundred and fifty nasal swabs were collected and processed using standard protocols. All the samples showed significant growth and ninety-six (64%) yielded Staphylococcus aureus. Forty-two percent of the S. aureus isolated were resistant to methicillin and all the isolates showed resistance to the various classes of antimicrobial agents tested with the least against the aminoglycosides. CONCLUSIONS: Our results provide baseline information to clinicians and healthcare workers on the implications of possible spread of multidrug resistant strains of the organisms.

Incidence of fungi pathogens associated with root canal treatments, in Benin City, Nigeria.

In order that appropriate clinical interpretation of microflora and drug management of root canal infections would be achieved, the fungi contents of root canal following biomechanical instrumentation were determined. Mucor, yeast, candida, microsporium and fusarium species were recovered at the different stages of instrumentation. The presence of fungi could complicate root canal treatments. The possible implications of these findings in treatment failures are highlighted.

Aspects of microbial contamination of tablets dispensed in hospitals and community pharmacies in Benin City, Nigeria

PURPOSE: A research was carried out to investigate the incidence of microflora in tablets dispensed from large container packages used in hospitals and community pharmacies. It was designed to provide baseline data on the common biodegrading microorganisms associated with tablets in retail containers and to highlight the health implications of such observations and roles for pharmacists in self medication phenomenon in Nigeria. METHODS: The protocol for the study involved structured selection of representative named tablets from some public hospitals and community pharmacies within Benin metropolis. Constitutive microorganisms were elaborated and enumerated using standard microbiological protocols. RESULTS: Our results showed that all the tablets sampled had some form of microbial growth. However; aerobic mesophilic bacteria and fungi observed were within standard numerical limits. It was additionally observed that ascorbic acid and folic acid tablets; particularly from the community pharmacies failed the exclusive criteria for Enterobactereacea and Staphylococci. Tablets from public hospitals in general have lower incidence of exclusive microbial contamination; compared with community pharmacies. CONCLUSION: Tablets packed in large containers in retail pharmacies in Benin City are often contaminated with microbial growth. This has possible adverse consequences for those who obtain drugs stored in large containers

Studies on the genotoxic and mutagenic potentials of mefloquine

PURPOSE: The detection of mefloquine mutagenicity has not been achieved by the use of Salmonella typhimurium his TA1535; TA1537 as tester strains. With the introduction of improved and more sensitive strains; it is of interest to evaluate the current mutagenic and genotoxic status of the drug. This study presents data on the in-vitro mutagenic and genotoxic potentials of mefloquine hydrochloride clinically used as an antimalarial agent. METHOD : The mutagenicity potentials was investigated in the Escherichia coli WP[2] trp and WP[2] uvrA trp tester strains containing the plasmids; pEB017 and pKM101; and the Salmonella typhimurium TA97 containing pKM101. The genotoxicity potential was determined using the microscreen phage-induction assay. RESULTS: The presence of plasmids pEBO17 and pKM101 enhanced the detection of mutagenicity of mefloquine. Microsomal-activated mefloquine unequivocally elicited base-pair substitution mutagenicity. The genotoxicity test indicated that mefloquine was generally not genotoxic but was of the same potential mutagenicity as chloroquine phosphate. CONCLUSION: Melfloquine hydrochloride exhibits base pair substitution mutagenesis; but not potentially genotoxic; even though it showed concentration dependent cytotoxicity. Its use as a last line antimalarial agent should still be encouraged

Kinetics of absorption and elimination of ofloxacin in humans after oral and rectal administrations.

Ofloxacin pharmacokinetics have been studied in four healthy subjects after a single oral or rectal dose, each of 200 mg. For the oral dose tmax was about 2 h, Cmax 1.96 +/- 0.56 micrograms/ml and AUC1-15 15.22 micrograms/ml.h. Two-phase elimination pharmacol kinetics were observed for the oral dose, t1/2 for the rapid elimination phase was 3.3 h and for the slow phase 10 h. With the rectal dose tmax was 6 h, Cmax 0.71 +/- 0.44 microgram/ml and AUC0-15 7.58 micrograms/ml.h. The relative rectal bioavailability (AUC rectal/AUC oral) was 49.8%. Elimination rate of the rectal dose was generally slow (t1/2 = 9 h), an observation attributable to the sustained-release effect of the rectal suppository base, PEG 6000. The indication is that the rectal formulation cannot be substituted totally for the oral without first increasing the rectal dose; the 200 mg suppository can however be employed as a follow-up therapy to the oral dose in certain situations.

Colorimetric determination of the fluoroquinolones.

Ciprofloxacin, ofloxacin and norfloxacin formed an amber coloured complex with iron(III) nitrate nonahydrate. The complex, which formed instantaneously at room temperature, was stable. The solutions of the complex obeyed Beer's law at 370 nm, the wavelength of maximum absorption of radiation (lambda[max]). The A(1%) for norfloxacin, ofloxacin and ciprofloxacin was 202, 207 and 235 respectively. The formation of the complex was the basis for the quantitative and qualitative determination of the drugs. There was statistically no significant difference (P < 0.05) between the results obtained quantitatively by this colorimetric method and those obtained by the microbiological assay method.

Bacteriological investigation of infected root canals in Benin City, Nigeria.

Possible viable bacteria were isolated and determined through culture based on paper point inoculation from infected root canals of 50 patients who presented for endodontic therapy at the school of Dentistry, University of Benin Teaching Hospital and Central Hospital, Benin City. Eighty-one strains of bacteria were isolated from 50 patients. The bacterial isolates were Streptococcus species, (51), Klebsiella species (17), E. coll (5), Staphylococcus aureus (3), Micrococcus species (2), Neisseria spp. (2) and Lactobacillus. The isolation of Klebsiella spp from the study is particularly interesting, constituting 21% of all the isolated bacteria. The implications of these findings in root canal infections are presented.

Influence of oral co-administered metallic drugs on ofloxacin pharmacokinetics.

Following recent concern over probable interactions between the 4-quinolones and metal ions, the effect of co-administered drugs--sodium bicarbonate, potassium citrate, ferrous sulphate, magnesium trisilicate, calcium carbonate and aluminium hydroxide--on the saliva and urine pharmacokinetics of ofloxacin in healthy human volunteers has been investigated. The Cmax and AUC0-9 in saliva were generally in the range 1.05-1.40 mg/L and 4.89-6.16 mg.h/L, respectively, and were unaffected (P less than 0.05) by the metallic drugs, except aluminium hydroxide which lowered these values. Again, only aluminium hydroxide modified the Ka of ofloxacin, resulting in a slower absorption rate. However, none of the metallic drugs altered the T1/2 beta of the 4-quinolone in saliva. In-vitro studies using simulated gastric fluid showed that ferrous sulphate, aluminium hydroxide and calcium carbonate reduced ofloxacin availability to 67.4%, 69.3% and 73.8%, respectively. This effect was ascribed to the formation of complexes between ofloxacin and the metal ions concerned. Substantial correlation between in-vitro and in-vivo availability data was demonstrated in all cases except for ofloxacin combinations with ferrous sulphate and calcium carbonate. In general, there was also good correlation between the saliva and urine data.

The mutagenic activity of chlorpromazine.

The mutagenic activity of chlorpromazine hydrochloride based on the Ames plate incorporation test and the modified fluctuation test in the presence and absence of liver microsomal enzyme (S9 fraction) and NADPH was determined. The results indicated that chlorpromazine required activation for mutagenic activity for the reversion of some of the tester bacterial strains from tryptophan and histidine dependence to independence respectively. The positive response of Escherichia coli WP2 trp, uvrA, E. coli WP2 trp (pKM101 and pAQ1) and Salmonella typhimurium his TA102 indicated that chlorpromazine mediates base-pair substitution and frame-shift mutagenesis.

Expression of a novel R-plasmid pEB017 compared to pKM101 in Escherichia coli wild-type, recA and uvrA strains.

The expression of bacterial resistance to UV irradiation and nitrofurantoin by a novel R-plasmid pEB017 in DNA-repair-proficient (wild-type) and -deficient (recA; uvrA) host strains was compared to the effects of plasmid pKM101 in the isogenic strains. pEB017 partially protected the uvrA strain, and completely protected the wild-type and recA strains from the killing effect of UV irradiation; pKM101 had no effect on the recA strain and only enhanced the survival of the wild-type and the uvrA strains after UV irradiation. pEB017 conferred nitrofurantoin resistance 10-fold on the wild-type and the recA strains and 4-fold on the uvrA strain; pKM101 did not confer nitrofurantoin resistance on the wild-type and recA strains but gave 4-fold resistance in the uvrA strain.

A survey of antibiotic outpatient prescribing and antibiotic self-medication.

In order to assess patterns of antibiotic prescribing and self-medication, a survey was carried out of patients from Government and private hospitals (500 each) and of 1000 apparently healthy adults in Benin City, Nigeria. Ampicillin and tetracycline were the antibiotics commonly used for self-medication; the commonest reasons given for the self-medication were the treatment of sexually transmitted diseases, cough, stomach upsets and diarrhoea. Ampicillin was the commonest prescribed antibiotic; the commonest indications for prescription were soft-tissue, sexually transmitted, upper respiratory and gastro-intestinal infections. According to an assessment by four clinicians from a panel of eight in Government and private practice, 52% of the total prescriptions were judged to be appropriate whereas 30% were judged to be inappropriate by a majority of the physicians. The implications of this study for the control of bacterial resistance to antibiotics are discussed.