Francisca O. Nwaokorie

OCCURRENCE OF YEASTS, PSEUDOMONADS AND ENTERIC BACTERIA IN THE ORAL CAVITY OF PATIENTS UNDERGOING HEAD AND NECK RADIOTHERAPY

The aim of this study was to evaluate the occurrence of yeasts, pseudomonads and enteric bacteria in the oral cavity of patients undergoing radiotherapy (RT) for treatment of head and neck cancer. Fifty patients receiving RT were examined before, during and 30 days after RT. Saliva, mucosa, and biofilm samples were collected and microorganisms were detected by culture and polymerase chain reaction (PCR). The most prevalent yeasts in patients submitted to RT were Candida albicans, C. tropicalis, C. krusei, C. glabrata and C. parapsilosis. Citrobacter, Enterobacter, Enterococcus, Klebsiella, Proteus, and Pseudomonas were the most frequently cultivated bacteria. Before RT, targeted bacteria were cultivated from 22.2% of edentulous patients and 16.6% of dentate patients; 30 days after RT, these microorganisms were recovered from 77.8% edentulous and 46.8% dentate patients. By PCR, these microorganisms were detected from all edentulous patients, 78.1% of dentate patients. The presence of Gram-negative enteric roads and fungi was particularly frequent in patients presenting mucositis level III or IV. Modifications in the oral environment due to RT treatment seem to facilitate the colonization of oral cavity by members of family Enterobacteriaceae, genera Enterococcus and Candida.

Detection of toxigenic Clostridium perfringens and Clostridium botulinum from food sold in Lagos, Nigeria.

Food-borne diseases contribute to the huge burden of sickness and death globally and in the last decade, have become more frequently reported in Africa. In line with this, food safety is becoming a significant and growing public health problem in Nigeria. Diarrhoea is a common problem in Nigeria and has been reported but there has been little data on the possibility of clostridia as aetiological agents. Clostridium species are ubiquitous in the environment and in the gastrointestinal tract of man and animals and can serve as a marker for faecal contamination. We set out to determine the potential of these foods to transmit Clostridium species. A total of 220 food commodities from six local governments in Lagos State were sampled. Isolates obtained were identified based on cultural, morphological and biochemical characteristics. Toxinotyping was done using multiplex-PCR with primers specific for alpha, beta, epsilon and iota-toxin genes, enterotoxigenic cpe gene and neurotoxigenic BoNt gene. Fifty (22.7%) clostridial species were isolated of which 29 (58%) were identified as C.xa0perfringens. Toxinotyping of the 29 strains showed that 28 (96.6%) were toxin producing C.xa0perfringens type A while one (3.4%) was C.xa0perfringens type D. Two (4%) C.xa0botulinum species were isolated and identified by 16S rRNA sequencing, both harbouring BoNt/A gene. The contamination rates of food with Clostridium species show that food hygiene is a problem and Clostridium species may be a source of food borne disease in Lagos State, Nigeria.

Metagenomic insights into effects of spent engine oil perturbation on the microbial community composition and function in a tropical agricultural soil.

Analyzing the microbial community structure and functions become imperative for ecological processes. To understand the impact of spent engine oil (SEO) contamination on microbial community structure of an agricultural soil, soil microcosms designated 1S (agricultural soil) and AB1 (agricultural soil polluted with SEO) were set up. Metagenomic DNA extracted from the soil microcosms and sequenced using Miseq Illumina sequencing were analyzed for their taxonomic and functional properties. Taxonomic profiling of the two microcosms by MG-RAST revealed the dominance of Actinobacteria (23.36%) and Proteobacteria (52.46%) phyla in 1S and AB1 with preponderance of Streptomyces (12.83%) and Gemmatimonas (10.20%) in 1S and Geodermatophilus (26.24%), Burkholderia (15.40%), and Pseudomonas (12.72%) in AB1, respectively. Our results showed that soil microbial diversity significantly decreased in AB1. Further assignment of the metagenomic reads to MG-RAST, Cluster of Orthologous Groups (COG) of proteins, Kyoto Encyclopedia of Genes and Genomes (KEGG), GhostKOALA, and NCBI’s CDD hits revealed diverse metabolic potentials of the autochthonous microbial community. It also revealed the adaptation of the community to various environmental stressors such as hydrocarbon hydrophobicity, heavy metal toxicity, oxidative stress, nutrient starvation, and C/N/P imbalance. To the best of our knowledge, this is the first study that investigates the effect of SEO perturbation on soil microbial communities through Illumina sequencing. The results indicated that SEO contamination significantly affects soil microbial community structure and functions leading to massive loss of nonhydrocarbon degrading indigenous microbiota and enrichment of hydrocarbonoclastic organisms such as members of Proteobacteria and Actinobacteria.

AP-PCR and Antimicrobial Susceptibility Patterns of Fusobacterium nucleatum Associated with Chronic Periodontitis among Patients at Lagos University Teaching Hospital

Aims: To isolate, identify and evaluate the genetic diversity and antimicrobial susceptibility of F. nucleatum recovered from Nigerian patients with chronic periodontitis. Study Design: Cross-sectional design.

Genetic variation among Clostridium perfringens isolated from food and faecal specimens in Lagos

BACKGROUNDnClostridium perfringens is an anaerobic Gram-positive bacterium which is commonly present in the gastrointestinal tract of man and animals and causes enteritic diseases in animals and food poisoning in humans. Previous studies have looked at the epidemiological relationship between C.xa0perfringens isolates from outbreak source. In this study, the genetic diversity of C.xa0perfringens strains from non-outbreak food and faecal specimens was investigated for epidemiological purposes.nnnMETHODSnWe analyzed thirty-eight (38) Clostridium perfringens strains isolated from food and faecal specimens in Lagos State. Bacterial identification was done using colonial morphology, Gram stain reaction, conventional biochemical tests and PCR. Genetic analysis was performed using arbitrary primed polymerase chain reaction (AP-PCR) technique with oligonucleotide primer of random sequences (OPA-3) to determine the genetic diversity of C.xa0perfringens. The distance between the different bands produced were analyzed using numerical taxonomy and multivariate system software (NTSYS).nnnRESULTSnSeventeen (44.7%) C.xa0perfringens strains showed at least one polymorphic DNA patterns when genotyped. However, this method identified polymorphisms among the C.xa0perfringens species from which four genetic groups (1, 2, 3 and 4) were established.nnnCONCLUSIONSnOur findings suggest that there may be faecal contamination of food products and similar clones of Clostridium perfringens may be incriminated.

Assessment of the Knowledge and Perception of Probiotics among Medical Science Students and Practitioners in Lagos State

Aim: The study was conducted to assess the knowledge and perception of probiotics among medical science students and practitioners in Lagos state. Study Design: This is a questionnaire based survey. Place and Duration of Study: The study was conducted in Lagos state which is located in the south-western part of Nigeria. The questionnaires were distributed from March to August, 2013. Methodology: Predesigned pilot tested questionnaires were randomly administered to 270 medical science students and professionals from various health institutes in Lagos state. The knowledge level was scored 0-3 as poor, 4-6 as fair and 7-9 as good and analyzed using Epi info version 3.5.3.

Detection of FUS-1 (OXA-85), a class D beta-lactamase from Fusobacterium nucleatum subspecies Polymorphum in Nigeria.

Aims: Beta-lactamase production and subsequent resistance to β-lactam drugs has been a global concern in the treatment of Gram negative anaerobes. The aim of this study was to identify F. nucleatum strains producing Class D β-lactamase through the detection of FUS-1 (OXA-85) resistance gene. Place and Duration of Study: Department of Preventive Dentistry, Lagos University Teaching Hospital, Idi-Araba, between February 2010 and November 2010. Methodology: Twenty two oral clinical samples were obtained from patients with chronic periodontitis who admitted to previous use of amoxicillin. Antibacterial susceptibility of the bacterial isolates was determined by E-test on Brucella Blood agar. Amplification of Short Communication British Microbiology Research Journal, 3(4): 492-500, 2013 493 the bacterial DNA was carried out by PCR using F. nucleatum species-specific primer, FUS-1 specific for blaFUS-1 and strain-specific primers for subspecies nucleatum, fusiforme, polymorphum and vincentii. Results: From the 19 samples collected, F. nucleatum was isolated, and the identity of the isolates was confirmed by PCR. Four of the isolates produced similar bands with the control strain, 3 (15.7%) strains were able to produce amplication with FUS-1 primer specific for blaFUS-1 gene found in β-lactamase producing F. nucleatum subsp. polymorphum. Conclusion: This study shows the presence of class D β-lactamase producing F. nucleatum species in Nigeria.

A Review of Fusobacterium necrophorum Infections in Humans

The incidence of human infections caused by Fusobacterium necrophorum is recently on the increase and this is attributed largely to alteration in antibiotic usage pattern, malnutrition and poor oral hygiene. These infections are usually acquired exogenously from animals such as dogs, livestock or humans and ranges from mild sore throat to severe infections like Lemierre’s syndrome and Cancrum oris (NOMA). Fusobacterium necrophorum species produce characteristic toxins and virulent factors which are responsible for the severity of infections. Confirming the presence of these species is recommended during suspected infections. It would help in providing information on the antimicrobial sensitivity pattern so as to guide treatment and control of these severe infections as well as for epidemiological purposes. This review summarizes human infections associated with F. necrophorum providing information on their epidemiology, risk factors, pathogenicity, diagnosis and treatment.