Studies on the diversity, abundance and succession of hydrocarbon utilizing micro organisms in tropical soil polluted with oily sludge

A research was carried out in a tropical region to study the population of hydrocarbon utilizers in soil polluted with oily sludge. Plots were prepared to receive treatments with neat and emulsified oilysludge. These plots were further treated with fertilizer and bioaugmented with a consortium of hydrocarbon utilizers for six months. Results obtained indicated that, the presence of oily sludge in soilcaused the growth of diverse genera of oil degraders. The major genera of bacteria active in polluted soil were Pseudomonas, Bacillus and Acinetobacter, while fungal general were Aspergillus, Penicillium,and Mucor. Abundant microbial growth was observed during the first 60 days. Some organisms such as Pseudomonas, Bacillus, Penicillium, and Aspergillus were present in polluted soil throughout the experimental period, while others including Candida, Sporobolomyces and Rhizopus were found only during the first two months. Further analysis revealed that, succession of the hydrocarbon utilizers in polluted soil was subject to seasonal variations and depended primarily on the fraction of the oil being utilized at a specific time and also on the physiology of the micro organisms involved. In addition, the selective appearance and succession of hydrocarbon utilizers in the polluted soil were affected only by the presence of neat and emulsified oil in soil as compare to other treatment parameters. The practical implication of these findings suggests that reloading of oil in some treated plots could be carried outafter the first 90 days. Molecular techniques are underway to provide a more comprehensive study on this successional trend

Current antibiotic susceptibility profile of the bacteria associated with Surgical wound infections in the Buea health district in Cameroon

Background: Most surgical wounds seen in clinical practice in the Buea Health District, Cameroon are infected prior to arrival or while they are in the hospital. Sometimes the infection necessitates a combination of local wound site measures and systemic antibiotherapy to properly manage the patient.Objective: To identify the current antibiotic susceptibility profile of the common germs that cause surgical wound infections in the Buea Health District of Cameroon.Methods: A total of 2120 specimens comprising swabs from burns, ulcers, open or post-operative wounds were collected from hospitalized patients attending health institutions in Buea. The samples were collected from different anatomic sites of the patients. Cultures were effected from the specimens and bacteria isolated from infected wounds using standard microbiological techniques. Antibiotic susceptibility of the different isolates was determined.Results: Majority (79.8%) of the wounds were infected with pathogenic bacteria. The germs globally showed multi resistant patterns to commonly used antibiotics in the study area, especially to co-trimoxazol, doxycycline, chloramphemicol, ampicilline and aztreonam. However appreciable sensitivity was noted to ofloxacillin, perflacin, and ceftriazone.Conclusion: This study has revealed ofloxacin as the only antibiotic to which all the isolated bacteria from infected wounds were sensitive in the study area.Keywords: Wound infection, Antibiotic susceptibility profile, Buea Health District, Cameroo

Antimicrobial Resistance of Bacterial Agents of the Upper Respiratory Tract of School Children in Buea, Cameroon

The study was aimed at determining bacterial agents of the upper respiratory tract and the susceptibility patterns of isolates to antibiotics. In total, 200 throat swabs were obtained from students attending different boarding schools within the Buea Municipality and screened to obtain the prevalence of respiratory pathogens and to understand the antibiotic susceptibility patterns of isolates using standard microbiological procedure and the disc-diffusion test. Of the 200 samples screened, 112 (56%) had positive cultures with the dominant bacterial pathogens being Haemophilus influenzae (20%), followed by Streptococcus pneumoniae (15%), Klebsiella pneumoniae (11%), and Staphylococcus aureus (10%). Although 56% of the isolates were recovered from females compared to 44% from males, the difference was not statistically significant (p>0.05). Sixty-seven percent of the pathogens were isolated from the age-group of 10-13 years, 19.6% from the age-group of 14-17 years, and 12.5% from the age-group of 18-21 years. Antibiotic susceptibility testing revealed that gentamicin (92%) and cefuroxime (88.4%) were the most effective antibiotics against the isolates. Generally, susceptibility ranged from 0% to 92% depending on the antibiotic and the species of microorganism. Penicillin had the highest (100%) resistance to all the isolates. The findings revealed that students living in boarding schools in the Buea Municipality were at risk of acquiring upper respiratory tract infections from their peers since the upper respiratory tract of more than 50% of the students was colonized with respiratory pathogens. Although multidrug-resistant strains of organisms were identified, gentamicin and cefuroxime are recommended as the first-line antibiotics of choice against the pathogens. There is, therefore, a need for surveillance of nasopharyngeal carriage of resistant strains of these organisms, especially H. influenzae in unhealthy school children since the vaccine is yet to be introduced in Cameroon. The findings have clinical and epidemiological significance

Lubricating oil-degrading bacteria in soils from filling stations and auto- mechanic workshops in Buea, Cameroon: occurrence and characteristics of isolates

The discharge of used crankcase oil from vehicles is a major source of oil pollution in Buea. The objectives of this study were to isolate and characterize bacteria capable of effectively degrading andcleaning up waste engine oil in this locality and also to ascertain the influence of some environmental factors on the rates of degradation of these isolates. Seventy-two soil samples collected fromlubricating oil dump sites (3 auto-mechanic workshops and 3 petrol filling stations, comprising impacted soils) and uncontaminated plots (non-impacted soils) (controls) were analysed for oildegradingand heterotrophic bacteria following standard microbiological and biochemical methods. The ability of cultures to degrade lubricating oil was also tested individually and in mixed bacterial consortium at different temperatures and nutrient concentrations. Results were analysed using the chisquared test. P values of < 0.05 were considered significant. Heterotrophic bacterial counts were significantly higher (P < 0.05) in non-impacted than in impacted soils. Conversely, the population of oil degraders was significantly lower (P < 0.05) in non-impacted than in impacted soils. Oil degraders isolated included Pseudomonas fluorescens, Bacillus mycoides and Serratia marcescens. Of the pure isolates, Serratia marcescens degraded the highest amount of oil (36.2%). However, a mixed culture of the isolates proved to be more effective, degrading 38.1% of oil within 20 days. All the isolatesexhibited highest degradation at 32°C; and degradation rates of Pseudomonas fluorescens and Bacillus mycoides increased with increase in nutrient concentration. This study, the first of its kind in Buea, revealed the presence of oil-degrading bacteria in soils as well as the physico-chemical requirements of these bacteria for optimum degradation. This finding could be exploited in case of oil-spill clean-upcampaigns

Bacterial indicators of pollution of the Douala lagoon, Cameroon: Public health implications.

Background: Indiscriminate disposal of untreated wastes which are often heavily laden with sewage microorganisms some of which are pathogenic to humans into aquatic environments near cities could serve as potential dangers to human health. Objective: A prospective study was undertaken to investigate the scope of potential bacterial pathogens and to assess the extent of pollution of the Douala lagoon. Methods: A total of eighty water samples were collected fortnightly from the lagoon at five stations from March to October 2005 and analysed for heterotrophic bacterial densities, coliform counts, faecal coliform and faecal streptococcal counts. Bacteria were isolated and identified using standard microbiology and biochemical techniques. Results: High heterotrophic bacterial counts (33 × 105 –161 ×105 CFU/ mL), total coliform counts (1.8 ×102 - 2.4 ×102 CFU/ 100 mL), faecal coliform counts (2.2 × 102 – 2.4 × 102 CFU/ 100 mL) and faecal streptococcal counts (2.1 × 102 – 2.3 x 102 CFU/ 100 mL) were observed in all sampling stations. Eleven species of bacteria: Bacteroides fragilis, Proteus vulgaris, Klebsiella pneumoniae, E. coli, Enterococcus faecalis, Enterobacter aerogenes, Citrobacter freundii, Aeromonas hydrophila, Pseudomonas aeruginosa, Bacillus mycoides and Serratia marcesens, were frequently isolated. Conclusion: The presence of potential bacterial agents such as Bacteroides fragilis, Pseudomonas aeruginosa, Aeromonas hydrophila, Klebsiella pneumoniae and E. coli in the lagoon may pose a serious threat to the health and well being of users of the Lagoon and calls for urgent intervention. African Health Science Vol. 8 (2) 2008: pp. 85-8

Antimicrobial Resistance of Bacterial Agents of the Upper Respiratory Tract of School Children in Buea, Cameroon

The study was aimed at determining bacterial agents of the upper respiratory tract and the susceptibility patterns of isolates to antibiotics. In total, 200 throat swabs were obtained from students attending different boarding schools within the Buea Municipality and screened to obtain the prevalence of respiratory pathogens and to understand the antibiotic susceptibility patterns of isolates using standard microbiological procedure and the disc-diffusion test. Of the 200 samples screened, 112 (56%) had positive cultures with the dominant bacterial pathogens being Haemophilus influenzae (20%), followed by Streptococcus pneumoniae (15%), Klebsiella pneumoniae (11%), and Staphylococcus aureus (10%). Although 56% of the isolates were recovered from females compared to 44% from males, the difference was not statistically significant (p>0.05). Sixty-seven percent of the pathogens were isolated from the age-group of 10-13 years, 19.6% from the age-group of 14-17 years, and 12.5% from the age-group of 18-21 years. Antibiotic susceptibility testing revealed that gentamicin (92%) and cefuroxime (88.4%) were the most effective antibiotics against the isolates. Generally, susceptibility ranged from 0% to 92% depending on the antibiotic and the species of microorganism. Penicillin had the highest (100%) resistance to all the isolates. The findings revealed that students living in boarding schools in the Buea Municipality were at risk of acquiring upper respiratory tract infections from their peers since the upper respiratory tract of more than 50% of the students was colonized with respiratory pathogens. Although multidrug-resistant strains of organisms were identified, gentamicin and cefuroxime are recommended as the first-line antibiotics of choice against the pathogens. There is, therefore, a need for surveillance of nasopharyngeal carriage of resistant strains of these organisms, especially H. influenzae in unhealthy school children since the vaccine is yet to be introduced in Cameroon. The findings have clinical and epidemiological significance