Invasive group B streptococcal infections in adults, France (2007-2010).

Group B streptococcus (GBS) has emerged as an important cause of invasive infection in adults. Here, we report the clinical and microbiological characteristics of 401 non-redundant GBS strains causing adult invasive infections collected during a 4-year period (2007-2010). Bacteraemia without focus (43.4%) and bone and joint infections (18.7%) were the main clinical manifestations. The distribution of capsular polysaccharide (CPS) type showed that types Ia, III, and V accounted for 71.8% of all strains. Resistance to erythromycin increased from 20.2% in 2007 to 35.3% in 2010, and was mainly associated with CPS type V harbouring the erm(B) resistant determinant.

[Evaluation of the new chromogenic medium StrepB Select for screening of group B Streptococcus in pregnant women]. / Evaluation du nouveau milieu chromogène StrepB Select pour le dépistage anténatal des streptocoques du groupe B chez la femme enceinte.

OBJECTIVES: To compare and evaluate the new chromogenic StrepB Select (BioRad) medium to the Granada (bioMérieux) and Columbia horse blood agar plates (CH-BAP) for screening of Group B Streptococcus (GBS) vaginal colonization in pregnant women. METHODS: One hundred and ninety vaginal swabs were processed and the three media inoculated. All plates were examined after 18-24h incubation at 37 degrees C and reincubated for an additional 24h. All suspected colonies were identified as GBS by using a commercial Lancefield group-specific latex agglutination test. RESULTS: GBS were isolated in 32 samples (16.8%) by at least one medium. After 24h of incubation, GBS were recovered on CH-BAP in 16 samples (50%) compared to 28 (87.5%) for StrepB Select, and 27 (84.5%) for Granada. After 48h of incubation, 30 (93.7%) out of the 32 GBS vaginal carriers were positive with CH-BAP, StrepB Select and Granada. Other streptococcal and enterococcal species gave GBS-like colonies on StrepB Select medium implying the use of other tests to confirm GBS identification. We demonstrated that direct agglutination of GBS isolated all media with Pastorex StrepB accurately identified GBS. The two StrepB Select false-negative results corresponded to a very low colonisation rate. Two Granada false-negative results corresponded to non-haemolytic and non-pigmented GBS strains which were correctly identified on StrepB Select. Both selective media inhibit the growth of associated saprophytic flora. CONCLUSION: The use of the new StrepB Select chromogenic medium in routine laboratories may therefore markedly facilitate the rapid and accurate detection of GBS in vaginal samples.

[Systematic family screening in case of infant pertussis]. / Dépistage familial systématique dans la coqueluche du nourrisson.

The origin of contamination in pertussis of young infants is generally the close relatives. From 2000 to 2004, only serology and culture were available in our hospital. The families of 16 young infants (age below one year) hospitalized for pertussis were screened using serological tests: 21/48 contacts were positive. After 2004, PCR was available for exploration of index cases and families: 35/85 contacts were positive. Of the mothers tested 23/46 were positive compared to 14/41 fathers. Only one parent presented with a typical paroxystic pertussis cough, 60% presented with a nonparoxystic cough having lasted for more than five days and 40% of positive adults did not present with cough. Despite official recommendations, none of these young parents had received an antipertussis booster vaccination. This study shows the high frequency of atypical or nonsymptomatic pertussis in adults in the close family of infected young infants. These adults contribute to spreading the disease.

Pertussis in young infants: apnoea and intra-familial infection.

This study investigated 41 infants, aged <4 months, who were hospitalised with symptoms compatible with pertussis. Of these, 16 had Bordetella pertussis infection confirmed by real-time PCR. For four of these 16 patients, the initial sample was PCR-negative, but samples collected 5-7 days after the onset of infection were PCR-positive. PCR was also positive with samples from 15/16 families and 20/41 household contacts. Nine of the 20 positive household contacts were asymptomatic. Among the 16 infants with proven pertussis, apnoea was more frequent than in a control group for whom PCR was negative with both children and household contacts (69% vs. 28%). It was concluded that real-time PCR performed with samples from household contacts facilitates the diagnosis of infants suspected clinically of having pertussis, thereby enabling earlier treatment.

Evaluation of the quality of hospital food from the kitchen to the patient.

Food-borne pathogens can multiply if food is not maintained at an appropriate temperature and if there are delays between food preparation and distribution. The aim of this study was to evaluate the quality of meals during transport from the kitchens to the patients in three departments of a university hospital. Meals were transported inside insulated, cooled food carts. We analysed the delays at each step of the transport process, and measured the temperature inside the food cart and inside the meals. The total duration of the transport (mean=85.3 min; range 44-123 min) conformed to the official recommendations (<2 h at a temperature <10 degrees C before consumption). The internal temperature of 73.6% of the 30 food carts followed was below 10 degrees C. The internal temperature of the meals was below 10 degrees C in 91.7% of cases when the food cart was first opened, but in only 12% of cases by the time the last patient was served. No pathogens were isolated from any of the samples. However, 10% of meals, all of which were salads, had total viable counts of bacteria above the recommended limits. This study confirms that it is essential to control time and temperature to ensure food quality and safety in hospitals.

Moderate inhibitory effect of interleukin-10 on human neutrophil and monocyte chemotaxis in vitro.

Neutrophils and monocytes are the major classes of phagocytes that migrate from the blood stream and accumulate in inflamed tissues in response to various chemoattractants. Because IL-10 is a potent anti-inflammatory cytokine, we analyzed its in vitro effect on chemotaxis using an under agarose method. We found that, as compared to prednisolone, IL-10 alone was a modest inhibitor of C5a, fMLP and IL-8-induced neutrophil chemotaxis, and C5a-induced monocyte chemotaxis. However, GM-CSF pretreatment of the cells potentiated this inhibitory effect. Similarly, the IL-10 induced modulation of the beta2 integrin CD11b/CD18 adhesion molecule expression was only observed on GM-CSF-preactivated neutrophils and monocytes. Taken together, these results suggest that the migration and accumulation of phagocytes at infection sites would not be significantly affected by IL-10 given as an immunomodulatory therapy.

Absence of regulation of human polymorphonuclear oxidative burst by interleukin-10, interleukin-4, interleukin-13 and transforming growth factor-beta in whole blood.

Cytokines such as IL-10, IL-4, IL-13 and TGF-beta play a major role in the regulation of immune responses and are considered as anti-inflammatory agents mainly due to their actions on monocytes. These cytokines are also known to participate in the regulation of PMN activities. However, few and contradictory results have been reported on their direct and priming effects on the PMN oxidative burst, which is essential for killing bacteria. We used a flow cytometry method to study the effects of these cytokines on the PMN oxidative burst; we also used whole blood to avoid PMN activation related to isolation procedures and in order to simulate the in vivo situation more closely. None of the cytokines tested had direct or priming effects on PMN H2O2 production. We also show for the first time that these cytokines do not modulate TNF priming of the PMN oxidative burst in response to N-formyl peptides (fMLP). These results show that the anti-bacterial activity of PMN, in terms of the PMN respiratory burst, is not down regulated by these anti-inflammatory cytokines in whole blood.