[Bacteriological study of purulent otitis media in children in CHU in the tropical zone]

Particularities of bacterial ecology of acute otitis media in an African subtropical country (Cote d'Ivoire)

BACKGROUND

Acute otitis media (AOM) is the commonest infectious disease of childhood. Its treatment is based on a probabilistic antibiotic therapy.

OBJECTIVE

To determine the prevalence of different bacteria responsible for AOM in children in Abidjan (Côte d'Ivoire).

MATERIALS AND METHODS

This is a prospective study, between November 2002 and August 2003. To identify bacterial isolates, 60 children under 15 years old with AOM were enrolled. In 52 cases, the sample was recovered by aspiration of a spontaneous otorrhea and in eight cases, it was taken by paracentesis. Nasopharyngeal swabs were cultured. Antibiotic susceptibility tests were performed on isolates.

RESULTS

75% of children were under 24 months of age. Pseudomonas aeruginosa was recovered in 31.8% of cases followed by Streptococcus pneumoniae (21%), Proteus (7.4%) and Staphylococcus (6.2%). The rate of penicillin-nonsusceptible S. pneumoniae (NSSP) was 11.8%. Resistance to erythromycin was 6%. For Pseudomonas, resistances to antibiotics were 35.5% to ceftazidim and 16% to pefloxacin, respectively, but all the strains were sensible to colistin, iminepem and ciprofloxacin.

CONCLUSION

These data can modify therapeutic approaches for treatment of AOM in our country. This study should encourage surveillance of AOM microbiology.

Nasal carriage of staphylococcus aureus and epidemiology of surgical-site infections in a Sudanese university hospital

Surgical site infections (SSI) due to Staphylococcus aureus among 256 male and 158 female patients (mean age, 28 years) undergoing elective surgery at the Soba University Hospital (Khartoum, Sudan) were studied. During an 11-month study period all patients were analyzed for nasal carriage of S. aureus at the time of admission. Follow-up of the development of SSI proceeded until 4 weeks after the operations. In addition, nasal swabs were obtained periodically during the same period from 82 members of the staff. In order to discriminate autoinfection from cross infection, bacterial isolates were typed by random amplification of polymorphic DNA (RAPD), pulsed-field gel electrophoresis (PFGE) of DNA macrorestriction fragments, and restriction fragment length polymorphism analysis of the protein A and coagulase genes. Preoperative cultures revealed the presence of S. aureus in the noses of 98 patients (24%). The overall number of postsurgical wound infections in the entire group was 57 (14%), 24 of which were due to S. aureus. Only 6 of the 98 nasal S. aureus carriers suffered from wound infections by the same species. In these six cases the infecting strain could not be genetically discriminated from the nasal inhabitant, substantiating autoinfection. However, nasal carriage of S. aureus is not a significant risk factor for the development of SSI in this setting (6 of 98 patients with autoinfection versus 18 of 316 patients [414 - 98 patients] with cross infection; P = 0.81), most probably due to the fact that noncarriers are at a significant and relatively large risk for acquiring an independent S. aureus SSI. The other S. aureus strains causing SSI showed a high degree of genetic heterogeneity, demonstrating that it is not an epidemic strain that is causing the SSI. Among the staff personnel screened, 47.4% did not carry S. aureus in the nose at any time during the study period, whereas 13. 2% persistently carried a single strain in the nose. Another 39.5% could be classified as intermittent carriers. When strains derived from staff personnel were genetically typed, it was demonstrated that most of the strains represented genetic variants clearly differing from the isolates causing SSI. On the other hand, possible cross colonization among staff personnel and even cross infection from staff personnel to patients or from patient to patient were demonstrated in some cases, but epidemic spread of a single strain or a few clonally related strains of S. aureus could be excluded.

[Bacteriological study of purulent nasopharyngitis in children in Senegal]

BACKGROUND

S pneumoniae, H influenzae and M catarrhalis are the main bacteria isolated from rhinopharynx in Europe. The purpose of this work was to study the frequency of potential pathogenic bacteria isolated from acute purulent rhinopharyngitis among children in Senegal.

POPULATION AND METHODS

Ninety-three children from one month to 7-years old suffering from purulent rhinopharyngitis were recruited from April 1 to July 1996. The withdrawal samples were taken from the cavum with a swab which was immediately immersed in an agar shipping medium. Bacteria's grouping and serotyping were made by immunoagglutination. A standard antibiogram was made for all isolates and furthermore the minimal inhibitory concentration (MIC) were determined for S pneumoniae.

RESULTS

Two hundred bacterial strains were isolated: S pneumoniae 28% (60% of the children), C group streptococci: 19% (41% of the children), H influenzae: 15.5% (33% of the children), S pyogenes: 9.5% (20% of the children), S aureus: 8% (17% of the children) and M catarrhalis: 6% (13% of the children). The other isolates were: B and D groups streptococci, P aeruginosa and Klebsiella spp. S pnuemoniae strains belonged to serogroups 6, 19 and 23. Only three strains of H influenzae were capsulated (serotype b). Infants aged from 6 to 18 months were the most affected. No resistance to penicillin was observed for S pneumoniae and S pyogenes. Ampicillin (81%) and chloramphenicol (96%) both inhibited the majority of H influenzae strains.

CONCLUSIONS

This descriptive bacterial epidemiology study of children's rhinopharynx's flora in Senegal allowed us to identify three major pathogenic germs: S pneumoniae, H influenzae and S pyogenes contributing to a better knowledge of these microorganisms' serotypes, biotypes and antibiotypes.