Occurrence of otitis media in children and assessment of treatment options.

BACKGROUND: Otitis media is a more frequent occurrence in children, and the disease may progress from an acute to chronic state if appropriate and timely intervention is not initiated. METHODS: A total of 212 children aged 6 months to 10 years were examined and treated for otitis media, in a 13-month hospital-based study. RESULTS: Acute otitis media was diagnosed in 130 (61.3 per cent) of the patients. There were 82 (38.7 per cent) chronic suppurative otitis media cases. The incidence of acute otitis media and chronic suppurative otitis media in the first year of life was 54.6 per cent and 45.1 per cent respectively. Chronic suppurative otitis media patients were assigned to one of three treatment groups. Recovery occurred in 70.4 per cent of amoxicillin-treated patients, in 88.9 per cent of amoxicillin-clavulanic acid treated patients and in 96.4 per cent of culture and antibiotic sensitivity test patients. Relapses were seen only in the amoxicillin (five cases) and amoxicillin-clavulanic acid (two cases) groups. CONCLUSION: The success rate in patients treated with antibiotics makes this option mandatory for an established diagnosis.

Microbiological status of periodontal diseases in Lagos, Nigeria.

OBJECTIVES: The dynamic nature of oro-facial infections made it imperative to study the epidemiology of gingivitis and periodontitis which are significant clinical conditions in the Nigerian environment. METHODS: The clinical and microbiological features of 162 patients with periodontal diseases (gingivitis 68, periodontitis 94) were analysed. The advantage of routine antibiotic susceptibility testing for oral pathogens in patients' management was investigated. RESULTS: The incidence of periodontal diseases was more in females than males with a ratio of 0.53 though the difference was not significant. A high incidence of gingivitis (55.9%) occurred within the first 29 years with a cluster of cases (48.6%) between 10 and 29 years of age with incidence tending to decline with advancing age. Though the incidence ofperiodontitis was highest amongst adults over 40 years (42.6%), the incidence of 8.5% in children below 10 years of age was high. Polybacterial aetiology was characteristic; aerobes were the predominant flora in gingivitis with a preponderance of Streptococcus spp, while anaerobes predominated in periodontitis with such species as Porphyromonas, Prevotella, Fusobacterium and Actinobacillus. Significant reduction in duration of treatment was obtained when patients were treated based on susceptibility results as opposed to empirical knowledge (p < 0.05). CONCLUSION: The diversity of microbial aetiology of periodontal infections may put much demand on routine laboratory investigations for patient management, but it may be necessary to weigh the benefit of additional cost against the cost of treatment failure associated with antibiotic resistance in bacteria.

Bacteriological and clinical evaluation of twelve cases of post-surgical sepsis of odontogenic tumours at a referral centre.

OBJECTIVE: To determine the bacterial aetiology of sepsis occurring following surgery of odontogenic tumours and assess the effect of prompt and proper antibiotic usage. DESIGN: A prospective study. SETTING: A tertiary referral centre in Lagos, Nigeria. SUBJECTS: Twelve patients with odontogenic tumours that developed sepsis postoperatively. Eight of the patients were referred from private hospitals, the remaining were in-patients who sought for alternative medical attention following interruption of health care services at the referral centre. INTERVENTION: Adequate review of patient's medical history, bacteriological investigations and antibiotic therapy. MAIN OUTCOME MEASURES: Bacteriological and clinical cure following antibiotic therapy based on susceptibility test results. RESULTS: Two categories of patients were identified; those who completed the course of antibiotics prescribed post-surgery and patients who failed to conform to antibiotic prescription. Sepsis developed in the non-compliance group much earlier than in the group that complied (p<0.001). Infections were polybacterial with aerobes accounting for 77.4% (alpha-haemolytic streptococci 29.0%, Streptococcus pyogenes 16.1%, Staphylococcus aureus 16.1%, diphtheroids 9.7%, Klebsiella pneumoniae 6.5%) and anaerobes 22.6% (Porphyromonas gingivalis 9.7%, Peptostreptococcus spp. 6.5%, Prevotella melaninogenica 3.2%, Clostridium perfringens 3.2%). Mixed aerobic and anaerobic aetiology occurred more in osteosarcoma and fibrosarcoma. Clostridium perfringens was isolated from a case of osteosarcoma with necrotic tissues. The anaerobic bacteria were 100% sensitive to metronidazole, ciprofloxacin and augmentin, 65-85% sensitivity to ampicloxacillin, amoxicillin and erythromycin. Over 92% of the streptococci were sensitive to the beta-Lactams contrast low susceptibility with S. aureus and K. pneumoniae. CONCLUSION: Interruption of healthcare service was the sole factor identified in the development of sepsis as the patients could not be monitored to ensure compliance to prescription.

Bacteriology of sachet water sold in Lagos, Nigeria.

OBJECTIVES: To investigate the health risks associated with methods of hawking of sachet water in the streets of Lagos. DESIGN: Eight brands of sachet water were collected from four different receptacles; unopen packs from factory, pail and wheelbarrow containing ice-blocks as coolants, and domestic refrigerators. Bacterial cultures were set up for the following samples; water contained in sachet, surface of the sachet, swabs from compartments of the refrigerators and wastewater of defrosted ice in pail and wheelbarrow. SETTING: This was a community based-study including three urban centers with high population density. MAIN OUTCOME MEASURES: The qualitative and quantitative differences in bacterial isolates from the different samples were analyzed for statistical significance. Septic and aseptic methods of sampling were adopted to investigate whether surface contaminants may impact significantly on the bacteriological quality of the sachet water. RESULTS: Enteric pathogens and Escherichia coli were not isolated from any samples and brands of sachet water but formed significant part of the isolates on the sachet surfaces of samples collected from the cooling receptacles (pail, wheelbarrow and refrigerator). Similar species of bacteria were isolated from wastewater and surface of the sachets with the wastewater containing a significant higher numbers of bacteria (p < 0.05). Aseptic technique of sampling did not significantly contribute to microbial load of the sachet water (p > 0.05). CONCLUSION: Organisms contained in the wastewater were inevitably the source of contaminants on the sachet surface. The water vendors and their patrons contributed to the overall contamination of hawked sachet water.

Survival and surface adherence ability of bacterial pathogens in oral liquid pharmaceuticals and their containers.

The survival and surface adherence ability of Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa in nutrient broth and in five oral liquid pharmaceuticals (nivaquine syrup, cough mixture, paracetamol elixir, cotrimoxazole and vitamin C) were investigated The bacteria grew more in nutrient broth than in the pharmaceuticals (p < 0. 001) and the recovery of stressed cells was enhanced when 3% Tween 80 was used as the recovery medium as against the use of normal saline (p < 0.01). The Gram-negative bacteria were more adapted to the pharmaceuticals than their Gram-positive counterparts. Klebsiella pneumoniae and Ps. aeruginosa were recovered in large numbers from nivaquine and cotrimoxazole suspensions that did not support the growth of the other bacteria. The effect of bacterial growth on the physico-chemical properties of the pharmaceuticals was also evaluated The properties were not altered significantly except for pH shifts of 0.3 to 1.1 caused by E. coli and S. aureus in paracetamol and vitamin C. Adherence capability was found to correlate with the survival ability of the bacteria. Populations on coupons were significantly higher when nutrient broth was used as the suspending medium compared with any of the pharmaceuticals (p < 0.01). Rubber and plastic coupons were significantly more accessible to the bacteria than glass coupon as revealed by the high population of bacteria recovered from their surfaces.

Survival and surface adherence ability of bacterial pathogens in oral liquid pharmaceuticals and their containers

The survival and surface adherence ability of Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa in nutrient broth and in five oral liquid pharmaceuticals (nivaquine syrup, cough mixture, paracetamol elixir, cotrimoxazole and vitamin C) were investigated The bacteria grew more in nutrient broth than in the pharmaceuticals (p < 0. 001) and the recovery of stressed cells was enhanced when 3 Tween 80 was used as the recovery medium as against the use of normal saline (p < 0.01). The Gram-negative bacteria were more adapted to the pharmaceuticals than their Gram-positive counterparts. Klebsiella pneumoniae and Ps. aeruginosa were recovered in large numbers from nivaquine and cotrimoxazole suspensions that did not support the growth of the other bacteria. The effect of bacterial growth on the physico-chemical properties of the pharmaceuticals was also evaluated The properties were not altered significantly except for pH shifts of 0.3 to 1.1 caused by E. coli and S. aureus in paracetamol and vitamin C. Adherence capability was found to correlate with the survival ability of the bacteria. Populations on coupons were significantly higher when nutrient broth was used as the suspending medium compared with any of the pharmaceuticals (p < 0.01). Rubber and plastic coupons were significantly more accessible to the bacteria than glass coupon as revealed by the high population of bacteria recovered from their surfaces

An experimental mouse model to study the pathogenicity of Prevotella bivia and investigations of possible virulence.

Induction of subcutaneous abscesses in mice was used to study the pathogenicity of Prevotella bivia both in mono-infection and in mixed cultures with Escherichia coli and Peptostreptococcus spp. Virulence factors such as coaggregation and aggregate formation of cells, haemagglutination activity and tolerance to serum bactericidal activity were investigated for their possible role in P bivia pathogenicity. Monocultures of P bivia, E coli and Peptostreptococcus spp did not induce subcutaneous abscess at concentrations as high as 10(9) colony forming units/millilitre (cfu/ml). Only E coli persisted at the infection site for up to 7 days post infection but with a marked decline in cell count (8.0 x 10(2) cfu/ml). The anaerobic organisms did not persist at the infection sites beyond the fifth day. In contrast, mixed cultures of P bivia and E coli or all three organisms potentiated for infective abscess two weeks after infection. Viable cells were recovered from abscesses in greater numbers as the infection progressed. Prevotella bivia was the predominant organism in chronic abscesses while E coli predominated in abscesses in the acute stage of the infection. Prevotella bivia lacked haemagglutination activity against human and sheep erythrocytes and showed marked susceptibility to 50 per cent human serum. These may limit its haematogenous spread. Its ability to form aggregates in molar salt solutions and coaggregate with facultative organisms may account for its persistence in pathological sites.

An experimental mouse model to study the pathogenicity of Prevotella bivia and investigations of possible virulence

Induction of subcutaneous abscesses in mice was used to study the pathogenicity of Prevotella bivia both in mono-infection and in mixed cultures with Escherichia coli and Peptostreptococcus spp. Virulence factors such as coaggregation and aggregate formation of cells, haemagglutination activity and tolerance to serum bactericidal activity were investigated for their possible role in P bivia pathogenicity. Monocultures of P bivia, E coli and Peptostreptococcus spp did not induce subcutaneous abscess at concentrations as high as 10 9 colony forming units/millilitre (cfu/ml). Only E coli persisted at the infection site for up to 7 days post infection but with a marked decline in cell count (8.0x10 squaredcfu/ml). The anaerobic organisms did not persist at the infection sites beyond the fifth day. In contrast, mixed cultures of P bivia and E coli or all three organisms potentiated for infective abscess two weeks after infection. Viable cells were recovered from abscesses in greater numbers as the infection progressed. Prevotella bivia was the predominant organism in chronic abscesses while E coli predominated in abscesses in the acute stage of the infection. Prevotella bivia lacked haemagglutination activity against human and sheep erythrocytes and showed marked susceptibility to 50 percent human serum. These may limit its haematogenous spread. Its ability to form aggregates in molar salt solutions and coaggregate with facultative organisms may account for its persistence in pathological sites.(Au)

Crayfish broth for bacterial culture.

OBJECTIVE: To formulate a new growth medium for bacteriological studies. METHODS: Sun dried white shrimps, Nematopalaemon hastatus, were ground into fine powder and infused in distilled water at 7+/-1 degrees C for 24 h. The pH of the infusion was adjusted to 7.2 with NaOH (0.1 m) and HCl (0.1 m) and evaporated to dryness. Crayfish broth (CB) was produced by reconstituting the concentrate in distilled water and sodium chloride was added at 0.9% w/v. Crayfish infusion agar (CIA) and crayfish starch agar (CSA) were prepared with CB as nutrient base. The crayfish broth and agar were evaluated alongside with nutrient broth and agar (Oxoid) for ability to support growth of pathogens such as Escherichia coli, Klebsiella aerogenes, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis. Crayfish broth was tested for suitability for sugar fermentation and indole test and results compared with those obtained with peptone water. Its suitability as a sensitivity test medium was evaluated using ampicillin (10 microg) and gentamicin (10 microg) discs and results compared with those obtained using Mueller-Hinton agar (Oxoid). RESULTS: Crayfish broth comprises crayfish infusion concentrate 3.5 g and sodium chloride 9.0 g dissolved in one litre of distilled water. The crayfish broth, CSA supported the growth of the test pathogens with cultural characteristics similar to those seen on nutrient agar. The pH of the spent crayfish broth was near neutral (pH 6.9). The broth was as important as peptone water for sugar fermentation test but was not suitable for indole test. The results of antibiotic susceptibility test on CIA were comparable with those obtained on Mueller-Hinton agar with difference in zone diameters of not more than 1 mm. CONCLUSION: Crayfish broth possesses enormous potential as a new growth medium for bacterial studies.

Incidence of pyrexia in patients undergoing haemodialysis.

Four patients on maintenance haemodialysis at the Lagos University Teaching developed pyrogenic reactions during treatment. Blood cultures were negative but the haemodialysates were grossly contaminated, mostly with Gram-negative bacilli, implicating their endotoxin as the cause of the observed pyrogenicity. The water reservoirs supplying the dialysis centre were grossly contaminated (counts 2.0 x 10(2) cfuml-1) with Gram-negative bacteria such as Pseudomonas aeruginosa, Ps. fluorescens, Alcaligenes faecalis, Achromobacter spp. and a Gram-positive organism, Micrococcus spp. These were the organisms isolated from the haemodialysates. At each sampling time, though fewer bacterial species were isolated from the haemodialysates, contrast the water reservoirs, the population of each bacterial type recovered from both samples was higher in the haemodialysates indicating a build up of the organisms within the haemodialysis machines. These findings therefore call for regular monitoring of the level of contamination of water use for mixing haemodialysis fluid in order to know when critical level is being exceeded.

Antibiotic susceptibility of clinical isolates of Prevotella bivia in Lagos, Nigeria.

The susceptibility of 40 clinical isolates of Prevotella bivia to 11 anti-anaerobic agents was determined by disk diffusion and agar dilution methods in accordance with the NCCLS (1990) recommended guidelines. With the disk diffusion method all the P. bivia tested were susceptible to rifampicin, cefoxitin, chloramphenicol, clindamycin and metronidazole. Twelve (30%) isolates were resistant to cefotaxime and ceftriaxone while 2 (5%) each were resistant to tetracycline and erythromycin. Worthy of note, 39 (97.5%) and all 40 (100%) isolates were resistant to ampicillin and penicillin respectively. Determination of minimum inhibitory concentrations (MIC) showed that the first set of 5 antibiotics, except rifampicin, were shown to be as active against all the strains tested as with the disk diffusion sensitivity method: cefoxitin, chloramphenicol, clindamycin and metronidazole had MIC90 values ranging from 0.5-1 microgram/ml. The MIC90s of erythromycin and tetracycline were 4 micrograms/ml each while the range of MIC of cefotaxime and ceftriaxone was 0.5-32 micrograms/ml with a MIC90 of 8 micrograms/ml, well below their breakpoints, which is somewhat at variance with disk diffusion results. The clinical significance of this, however, is not clear, especially in the absence of controlled clinical trials. Ampicillin and penicillin MIC90 values were 64 micrograms/ml and 80 U/ml respectively which essentially confirmed the resistance observed by the disk method. All the P. bivia isolates were beta-lactamase producers, hence the resistance of these isolates to penicillin and ampicillin. It is conceivable that in infections with monoculture of P. bivia, agents like tetracycline, or erythromycin may still be a useful alternative for treatment.

Survival of bacteroides species in Amies transport medium stored at different temperatures.

The viability of four Bacteroides species in Amies medium at different temperatures was evaluated by a series of quantitative and qualitative experiments using B. bivius, B. disiens, B. fragilis and B. melaninogenicus. In the quantitative assessment, the Bacteroides spp. were recovered from Amies transport medium stored at -20 degrees C up to the six weeks of storage. At -10 degrees C no Bacteroides spp. was recovered after two weeks. At both storage temperatures, B. fragilis showed the highest survival rate. In the qualitative assessment, the test strains were recovered after four months of storage at -20 degrees C in Amies medium with noticeable decline in number of surviving bacteria towards the end of that period. The effect of thawing and refreezing was also assessed and was found to affect survival rate considerably. Our results provide an alternative, convenient and cheaper method of preserving anaerobes.