[Molecular characterization of invasive Haemophilus influenzae strains isolated in Tunisia]. / Caractérisation moléculaire des souches invasives d'Haemophilus influenzae isolées dans la région du Sahel tunisien.

We reported a molecular characterization of 25 Haemophilus influenzae strains derived from cases of meningitis and sepsis in children aged less than five years hospitalized in pediatric wards from three hospitals in the Sahel area (Tunisia) during the period 1997-2002. These strains were biotyped and subjected to a capsular typing by Slide agglutination serotyping and Polymerase Chain Reaction (PCR). The genetic polymorphism of these strains was also studied in Arbitrarily Primed Polymerase Chain Reaction (AP-PCR) with two sets of primers: RAP IV and 217 delta(2) as in Pulsed Field Gel Electrophoresis after digestion of the total DNA with the restriction enzyme SmaI (PFGE SmaI). Nineteen strains among 25 (76%) were of biotype I. The bexA gene was highlighted in 13 strains (52%) and in all the cases it was of the type b. Twelve strains (48%) were shown to be unencapsulated by PCR. AP-PCR RAP IV (23 genotypes/25 with a discrimination index ID=0.993) had shown nearly the same discriminatory power than PFGE (20 genotypes/21 strains with a discrimination index ID=0.995). We thus note, how capsular typing by PCR is more sensitive than slide agglutination serotyping. We also note the genetic diversity of the invasive strains isolated with a remarkable presence of non typable strains. AP PCR seems to be an alternative of choice for the epidemiologic follow-up of the Haemophilus influenzae invasive infections.

[Epidemiologic markers in Haemophilus influenzae]. / Les marqueurs épidémiologiques chez Haemophilus influenzae.

Twenty-six strains of Haemophilus influenzae, isolated from diverse pathological products in two different hospitals in the center of Tunisia (Sousse-Monastir) have been compared with two different genotypic techniques: AP-PCR and pulsed-field gel electrophoresis. These two techniques showed a high discriminating power. The combination of the results of both techniques were complementary and have individualized twenty-five heterogeneous patterns among the twenty-six strains. Among the strains of respiratory origin, only two were identical, they have been isolated from two patients hospitalized in the same period and the same hospital. Excepted the two above mentioned cases, this study showed a high genetical heterogeneity of the strains.

[Contribution of phage typing and ribotyping in investigating a typhoid fever outbreak in Tunisia]. / Apport de la lysotypie et de la ribotypie dans l'investigation d'une epidémie de fièvre typhoïde en Tunisie.

A study was carried out to investigate an outbreak of typhoid fever that occurred in Sousse city and in the vicinity of Sousse (Tunisia) during summer 1999. Twenty four isolates of Salmonella enterica serotype Typhi were isolated in hospitalized patients with a typhoid fever in two hospitals (Farhat Hached Sousse and M'saken) and were studied with the help of two molecular typing methods: phage typing and automated ribotyping. Twenty one isolates with the Vi antigen had profile DVS (Degraded Vi Strain), one isolate with the Vi antigen belonged to phage type A and two isolates were non phage typable (no Vi antigen). The same ribotype was found in 22 out of 24 isolates. The results suggested that ribotyping is more discriminative than phage typing in this case in distinguishing strains and the strains shared the same source of the contamination. Unfortunately the precise source of the contamination could not be determined.

Outbreak of Pseudomonas putida bacteraemia in a neonatal intensive care unit.

During the period of 9-27 March 2001, Pseudomonas putida strains were recovered from 10 neonates hospitalized in the neonatal intensive care unit of Farhat Hached Hospital, Sousse (Tunisia). Seven neonates developed bacteraemia, and three had an umbilical catheter-related infection (without bacteraemia). A total of 18 isolates were cultured from blood (N = 11) and catheters (N = 7). These isolates were identified as P. putida by routine biochemical methods (API 20 NE, bioMérieux, Lyon, France). Restriction endonuclease DNA profiles were determined by pulsed-field gel electrophoresis using two endonucleases XbaI and SpeI. They yielded the same patterns showing that the outbreak was caused by a single clone of P. putida. Although the antiseptic solutions used to clean the umbilicus were implicated circumstantially as probable sources, they were not sampled and so this could not be confirmed.

Group A streptococci in children with acute pharyngitis in Sousse, Tunisia.

A 1-year prospective study in 2 paediatric outpatient clinics in Sousse, Tunisia, aimed to determine the presence of group A streptococci in acute pharyngitis cases and carriers, and the distribution of the serotypes and biotypes. Group A streptococci were found in 9.0% of throat swabs from 155 controls and 17.7% from 474 patients (P < 0.05). Of 43 strains isolated from patients and submitted for typing, 15 different types were identified, the most common being M75 (14 strains; 32.5%), M9 (6 strains; 14.0%), M76 (5 strains; 11.6%) and M12 (4 strains; 9.3%). Three strains were non-typeable (7.0%). Biotyping of the strains showed 3 predominant biotypes: biotype 3 (n = 14), biotype 2 (n = 11), and biotype 1 (n = 7).

Group A streptococci in children with acute pharyngitis in Sousse, Tunisia

A 1-year prospective study in 2 paediatric outpatient clinics in Sousse, Tunisia, aimed to determine the presence of group A streptococci in acute pharyngitis cases and carriers, and the distribution of the serotypes and biotypes. Group A streptococci were found in 9.0% of throat swabs from 155 controls and 17.7% from 474 patients [P < 0.05]. Of 43 strains isolated from patients and submitted for typing, 15 different types were identified, the most common being M75 [14 strains; 32.5%], M9 [6 strains; 14.0%], M76 [5 strains; 11.6%] and M12 [4 strains; 9.3%]. Three strains were non-typeable [7.0%]. Biotyping of the strains showed 3 predominant biotypes: biotype 3 [n = 14], biotype 2 [n = 11], and biotype 1 [n = 7]

[The reduction of methicillin resistance in Streptococcus aureus in a hospital environment in Sousse (Tunisia)]. / Diminution de la résistance a la méticilline chez Staphylococcus aureus en milieu hospitalier à Sousse (Tunisie).

The sensitivity of Staphylococcus aureus to the principal antibiotics has been studied in a hospital environment during the period of 1989 to 1992. The resistance to methicillin was important in 1989, 1990, and 1991 (respectively 20.5; 24 and 25%). It showed an important decrease in 1992: 5%. The outstanding point over this last period is the appearance of a lower number of multi-resistant strains: M penicillin, aminoglycosides, macrolides. These strains represented 9, 10 and 11.5% in 1989, 1990 and 1991 and only 4% in 1992. This study indicates the need for increased control of the ecology and distribution of resistant strains.