Epidemiology of Enterobacteriaceae producing CTX-M type extended spectrum ß-lactamase (ESBL).

Over the past 20 years, some Enterobacteriaceae mainly Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis have demonstrated acquisition of plasmids secreting ESBL. CTX-M type ESBL have been isolated worldwide and their incidence has increased dramatically and is still increasing leading to a major therapeutic issue. Currently more than 150 allelic variants of CTX-M have been identified. These enzymes are classified in five major phylogenetic groups based on their gene sequences: CTX-M -1, CTX-M-2, CTX-M-8, CTX-M-9, CTX-M-25; two additional groups have been reported recently: CTX-M-74 and CTX-M-75. The important dissemination of these enzymes has led to an increased use of carbapenems. Their global community and nosocomial dissemination is often associated with a virulent E. coli clone ST131 producing CTX-M-15.

[Severe community-acquired pneumonia admitted at the intensive care unit: main clinical and bacteriological features and prognostic factors: a Tunisian experience]. / Pneumopathies communautaires sévères en réanimation : caractéristiques cliniques, bactériologiques et facteurs pronostiques: une expérience tunisienne.

INTRODUCTION: Severe community-acquired pneumonia (SCAP) remains a major cause of death. The aim of this study was to describe the main clinical and bacteriological features and to determine predictive factors for death in patients with SCAP who were admitted in intensive care unit (ICU) in a Tunisian setting. METHOD: It is a retrospective study conducted between March 2005 and December 2010 at the intensive care unit of the University Hospital of Mahdia (Tunisia). All patients hospitalized at the ICU with a SCAP diagnosis according to the American Thoracic Society criteria were included. RESULTS: Two hundred and nine patients (mean age: 64±16 years, and mean SAPS II: 42±17) were included. Overall, 24% had a bacteriological diagnosis. Streptococcus pneumoniae was the most frequently detected. Use of mechanical ventilation was required in 57% of patients and 45% experimented septic shock upon admission. The mortality rate at ICU was 29% (n=60). In multivariate analysis, a septic shock at admission and the use of mechanical ventilation were both associated with death. CONCLUSION: SCAP were associated with high mortality in the ICU.

[Clinical outcome and prognosis of neonatal bacterial meningitis]. / Aspects cliniques et évolutifs des méningites bactériennes néonatales.

OBJECTIVES: To study the epidemiological, clinical, and bacteriological aspects as well as the outcome of neonatal bacterial meningitis and analyze the factors of poor prognosis of this condition. PATIENTS AND METHODS: We report a retrospective analysis of 44 cases of neonatal bacterial meningitis hospitalized in the pediatric unit of Tahar Sfar Hospital in Mahdia, Tunisia, between January 1996 and December 2010. Inclusion criteria were infants less than 29 days of age who were hospitalized for bacterial meningitis diagnosed on either the presence of bacteria in cerebrospinal fluid or with more than 50 cells/mm(3), predominance of neutrophils, and the protein level greater than 1.2g/l. Clinical data were obtained through the analysis of patient files. Statistical analysis was based on the Chi(2) test, and P-values less than 0.05 were considered statistically significant. RESULTS: The incidence of neonatal bacterial meningitis was 0.49 per 1000 live births. The patients were premature in 20.4 % and low birth weight in 13.6 % of cases. The clinical presentation was not specific for most cases. The main signs at admission were hyperthermia (43.2 %), refusal to nurse (20.4 %), seizures (18.2 %), and respiratory distress (13.6 %). The cerebrospinal fluid culture was positive in 36.4 % of cases. The group B streptococcus was the most frequently isolated (62.5 %) followed by Escherichia coli (12.5 %). The association of cefotaxime-ampicillin-gentamicin was used as the first treatment in all cases. Ofloxacin was associated with initial antibiotic therapy during the first 5 days in 20.4 % of cases. The mortality rate was 15.9 % and the rate of neurological sequelae in survivors was 21.6 %. Prematurity, low birth weight, shock, respiratory distress, and pleocytosis of less than 500 cells/mm(3) were the main factors of a poor prognosis. The addition of ofloxacin to the initial antibiotic therapy was associated with a decreased rate of neurological sequelae in survivors (11 % vs. 25 %, P=0.042). CONCLUSION: This study emphasizes the severity of neonatal bacterial meningitis with high rates of mortality and neurological sequelae, especially in premature and low birth weight infants. An early diagnosis and effective antibiotic therapy is needed to improve the prognosis.

[Epidemiological study of Klebsiella spp. uropathogenic strains producing extended-spectrum ß-lactamase in a Tunisian university hospital, 2009]. / Epidémiologie des souches de Klebsiella spp. uropathogènes productrices de ß-lactamases à spectre élargi dans un hôpital universitaire Tunisien, 2009.

OBJECTIVE: An update on the prevalence of antibiotic resistance in extended-spectrum ß-lactamase among urinary strains of Klebsiella spp. isolated from in-come and out-come patients at University Hospital, Mahdia (Tunisia). PATIENTS AND METHODS: A retrospective survey was made over a period of twelve months (year 2009). It focused on 3564 patients with urinary tract infection confirmed by the Laboratory of Microbiology in the University Hospital, Mahdia. RESULTS: Klebsiella spp. was involved in 5.5% (198/3564) of all cases of urinary tract infections identified. Klebsiella pneumoniae accounted for 94.9% of all Klebsiella (5.1% for Klebsiella oxytoca). The frequency of Klebsiella spp. resistance to fluoroquinolones was 19.2% and to third generation cephalosporins was 22.7%. Forty strains of Klebsiella spp. producing extended-spectrum ß-lactamase witch corresponds to 20.2% of all the Klebsiella. The extended-spectrum ß-lactamase strains with resistance to fluoroquinolones were 67.5% (27/40) or 13.6% of all klebsiella (27/198). No strain was resistant to imipenem. The 27 strains multiresistant (ESBL+FQ resistance) are likely to be carriers of plasmids encoding the ESBL and resistance to fluoroquinolones. CONCLUSION: the resistance of Enterobacteriaceae, including Klebsiella spp, to fluoroquinolones has become a concern both in hospital in community medicine. The advent of this resistance mechanism involves a more rational use of fluoroquinolones, especially as first-line treatment of urinary tract infections.

[Phenotypic and genotypic (randomly amplified polymorphic DNA analysis and multiple-locus variable-number tandem-repeat analysis) charaterization of 96 clinical isolates of Pseudomonas aeruginosa in the F. Bourguiba hospital (Monastir, Tunisia)]. / Caractérisation phénotypique et génotypique (randomly amplified polymorphic DNA analysis et multiple-locus variable-number tandem-repeat analysis) de 96 isolats cliniques de Pseudomonas aeruginosa à l'hôpital F. Bourguiba (Monastir, Tunisie).

AIM OF THE STUDY: Phenotypic and genotypic characterization of 96 clinical isolates of Pseudomonas aeruginosa recovered in a Tunisian teaching hospital during a 16-month period. MATERIALS AND METHODS: All the isolates were characterized by serotyping, antimicrobial susceptibility typing and genotyping with randomly amplified polymorphic DNA (RAPD) analysis and multiple-locus variable-number tandem-repeat analysis (MLVA). RESULTS: Forty-one isolates out of 96 (43%) were recovered from two intensive care units (medical and chirurgical). Most of the isolates (48%) belonged to serotype O:11. Among the 13 antibiotypes, three multidrug resistant ones were mostly observed within the two intensive care units. Genotyping showed 83 RAPD types and 52 MLVA types. Isolates showing the same serotype could show different genotypes. A limited number of clusters was highlighted with MLVA typing, of which an outbreak of nine cases within the surgical intensive care unit. CONCLUSION: Except this outbreak of nine cases, the heterogeneity observed for most of the P. aeruginosa isolates showed that outbreak situations were rare in the F. Bourguiba hospital during the study period. MLVA genotyping is a good tool for genotyping P. aeruginosa clinical isolates.

Frequence et profil de sensibilite aux antibiotiques des bacteries isolees des hemocultures au CHU de Mahdia

L'objectif de notre etude etait de determiner l'epidemiologie et le profil desensibilite aux antibiotiques des bacteries isolees des hemocultures dans le CHUde Mahdia; afin d'optimiser l'antibiotherapie probabiliste utilisee en premiere intention.Cette etude retrospective a ete realisee sur une periode de seize mois (Jui ll et2007 a Octobre 2008) et a concerne 398 isolats. Cinquante neuf pourcent des isolats etaient des bacilles a Gram negatif (BGN) dont 83;2d'enterobacteries. Les cocci a Gram positif representaient 39;7avec predominance de staphylocoques a coagulase negative (61;2). Les BGN non fermentant representaient 16;8. La resistance a l'oxacilline etait de 34;2pour les staphylocoques a coagulase negative. Les enterobacteries etaient resistantes aux C3G dans 50;5. Le taux de resistance de l'Acinetobacter baumannii etait de 62a la ceftazidime et de 51a l'imipeneme. Celui de Pseudomonas aeruginosa etait; respectivement de 35;3et de 18;7. Une surveillance epidemiologique des bacteriemies est necessaire; a l'echelle d'un hopital; pour mieux guider l'antibiotherapie probabiliste