[lnvestigaton of three nosocomial outbreaks of serratia marcescens in an intensive care unit in Sfax Tunisia]

Of the study was to type Serraria marcescens responsible for nosocnmial outbreaks in an intensive care unit in Stax-Tunisia. The relatedness between S. marcescens isolates was studied by Pulsed field get electrophoresis [PFGE]. We included 56 strains of Serratia marcescens isolated from patients hospitatized in the intensive care unit during 2003 and 2004. Seven epidemiological unrelated strains of Serratia marcescens were also tested. Samples from environment and hands of the nursing and medical staff were collected and cultured to identify the source of contanirnation. All strains showed a wild type of antimicrobial susceptibility. PEGE typing revealed that three different clones were present. None of the cultures taken from hands of unit staff and from environmental samples yielded positive results for S. snarcescens. We have confirmed the presence of three consecutive outbreaks caused by rhree genetically unrelated bacterial clones of Serraria marcescens in the intensive care unit ward. These outbreaks are closely related to the frequent use of colistin and the lack of measures of hygiene in this ward

Pseudomonas aeruginosa: etude multicentrique de la resistance aux antibiotiques [1999-2000]

A retrospective multicentric study was carried out over a period of 2 years [1999-2000]. 2659 strains of pseudomonas aeruginosa were collected from 4 university hospitals [charles Nicolle Hospital, pediatric Hospital and national center of Bone Marrow Transplantation in Tunis, Habib Bourguiba Hospital in Sfax]. Epidemiological profile and antibiotic susceptibility were analyesd. All bacteria were identified by conventional methods and antibiotic susceptibility tests were performed according to CA-SFM guidelines. The strains were recovered essrntially from surgical wards [33%] and intensive care units [22%]. Pseudomonas aeruginosa was isolated mainly from pus [36%] urine [32%]and respiratory samples [18%]. 25% of strains were resistant to ticarcilline, 18% to cefsulodine, 9% to ceftazidime, 14% to imipenem and amikacin and 25% to ciprofloxacin. Moreover, the resistance rates varied from hospital to hospital and from unit to another. The resistant strains were isolated particularly from urology and intensive care units: respectively 62% and 39% for ticarcilline; 26% and 13% for ceftazidime. The acquired resistance to b-lactams seems largely due to penicillinase production. The frequency of resistance to ceftazidime was the lowest and seem associated to chromosomal cephalosporinase over production

Profil epidemiologique des infections a H. influenzae en Tunisie

Haemophilus inluenzae, a commensal bacteria, is frequently incriminated in broncho pulmonary surinfections and severe diseases as meningitis, pneumonia and septic arthritis,particularly in young children. A multicenter study was conducted to establish the epidemiological profile of haemophilus influenzae, to determine the rate of antibiotics resistance for guide therapeutic and preventive strategies. The identification was based on the requirements for x and v factors, and the serotype b determined by agglutination. The betalactamase production was done by nitrocefin test. Antimicrobial susceptibility testing was determined on Muller Hinton chocolate agar with isovitalex. During the two year period, [January 1998 December 1999], 192 isolates of H. influenzae were collected, 61% were recovered from invasive infections [44 meninggitis, 8 bacteremia, 2 arthritis]. The serotype b was identified in 55.7% of cases, 67.3% were invasive strains. 24.5% of isolates were producing betalactamase particularly invasive serotype b strains. All isolates of H. influenzae were susceptible to cefotaxim and to ofloxacin. Resistance rates to other antibiotics were: erythromycin 56.2%, tetracycline 10.3%, rifampin 12%, chloramphenicol 1%, cotrimoxazole 16.5%, 11.5% amikacin and 20% gentamicin. The incidence of meningitis remained frequent in our country, involving the introducyion of the vaccination in offical calencedar. Nevertheless, the surveillance of H. influenzae invasives infections and the serotyping of isolates were necessary to evaluate the impact of the immunization