Antimicrobial susceptibility of clinical isolates of non-jejuni/coli campylobacters and arcobacters from Belgium.

OBJECTIVES: To determine the susceptibility of non-jejuni/coli campylobacters and arcobacters isolated from diarrhoeal stool specimens in Belgium. METHODS: The MICs were determined using Etest for six antimicrobial agents including ampicillin, erythromycin, nalidixic acid, ciprofloxacin, gentamicin and tetracycline for the most frequently isolated non-jejuni/coli campylobacter and arcobacter strains in two University Hospital laboratories between 1995 and 2005. RESULTS: In total, 85 Campylobacter upsaliensis, 20 Campylobacter concisus, 11 Campylobacter fetus, 61 Arcobacter butzleri and 10 Arcobacter cryaerophilus isolates were tested. Most C. upsaliensis strains were susceptible to ampicillin (100%), gentamicin (100%), ciprofloxacin (94.1%) and tetracycline (100%), whereas 11.8 and 12.9% were resistant to nalidixic acid and erythromycin, respectively. For A. butzleri, 78.7% of isolates were susceptible to ampicillin and erythromycin. Most A. butzleri isolates were susceptible to ciprofloxacin (96.7%), nalidixic acid (82.0%), gentamicin (100%) and tetracycline (100%). All C. concisus strains were fully susceptible to ampicillin and tetracycline, but 5% of them were resistant to gentamicin, ciprofloxacin and erythromycin. Nearly all C. fetus and A. cryaerophilus strains were susceptible to erythromycin but the results should be interpreted with caution since only a small number of strains were tested. CONCLUSIONS: Fluoroquinolones should be considered in the treatment of severe C. upsaliensis and A. butzleri infection. When clinically indicated, erythromycin remains the first choice for the treatment of intestinal campylobacteriosis caused by C. concisus and C. fetus.

Antimicrobial susceptibility patterns of Arcobacter butzleri and Arcobacter cryaerophilus strains isolated from humans and broilers.

The MICs of five antimicrobial agents were determined by the agar dilution method for 98 Arcobacter butzleri and 28 Arcobacter cryaerophilus strains from humans, and poultry. With gentamicin, a MIC of 16 microg/ml was recorded for one A. butzleri strain isolated from poultry, whereas for the other strains MICs ranged from 0.25 to 4 microg/ml. With ciprofloxacin, a bimodal distribution of susceptibility levels was seen for human A. butzleri isolates (0.015-0.03 versus 0.12-0.25), whereas MICs for 65 of the 68 A. butzleri poultry strains ranged from 0.12 to 0.5 microg/ml and three strains from three different broilers were resistant with a MIC of 16 microg/ml. One A. cryaerophilus strain from poultry was resistant to erythromycin at a MIC of 128 microg/ml, whereas MICs for the other Arcobacter strains ranged from 2 to 32 microg/ml. No difference in susceptibility or resistance among the human and poultry strains tested was observed with doxycycline and nalidixic acid. The presence of acquired resistance to erythromycin and ciprofloxacin among poultry isolates is a matter of concern, because the two antimicrobials are generally prescribed as first-line drugs for the treatment of infections with Campylobacteraceae in humans.

Improvements in nutritional management as a determinant of reduced mortality from community-acquired lower respiratory tract infection in hospitalized children from rural central Africa.

BACKGROUND: In-hospital mortality from lower respiratory tract infections (LTRI) is unacceptably high in developing countries where LTRI are still a leading cause of death. OBJECTIVE: To identify new approaches to reduce in-hospital mortality of LRTI through the improvement of its management. METHODS: The prospectively collected database of children admitted during an 11-year period with LRTI in a pediatric rural hospital in Central Africa was reviewed to determine the predictors of death and to evaluate the impact on mortality of 4 different protocols for the management of malnutrition. RESULTS: During the study period, 859 children were admitted with a nonmeasles severe LRTI. In the 3-year period during which blood cultures were obtained, 29.0% of the children with LRTI were bacteremic, and multiresistant Enterobacteriaceae were recovered in 81.4% of positive blood cultures. Independent predictors of death in children without edema were age <24 months, dehydration and hepatomegaly with adjusted odds ratios (numbers in parentheses, 95% confidence interval) of 3.47 (1.70-7.08), 4.24 (2.11-8.50) and 2.90 (1.43-5.85), respectively. In those with edema, a significantly increased risk of death was noted for girls [4.31 (1.71-10.90)], in children with z-score of weight to height < or = -3 [5.45 (1.67-17.79)] and when the serum albumin was <16 g/l [2.58 (1.01-6.58)]. The improvement in the management of malnutrition was followed by a reduction of LRTI-related mortality in children with edema from 32.4 to 8.9% (P < 0.001). In children without edema, the LRTI-related mortality decreased from approximately 12% to 3.5% when their diet was supplemented with micronutrients. CONCLUSION: This study indicates that the improvement of the management of underlying nutritional deficiencies is crucial for the reduction of the high in-hospital case fatality rate associated with severe nonmeasles LRTI. The empiric antibiotic regimen should be modified to cover for multiresistant Enterobacteriaceae.

Isolation and characterization of enteroaggregative Escherichia coli (EAggEC) by genotypic and phenotypic markers, isolated from diarrheal children in Congo.

OBJECTIVE: To determine the prevalence of enteroaggregative Escherichia coli (EAggEC) in African diarrheal children in Lwiro, Congo, to characterize EAggEC isolates by possible genotypic and phenotypic markers, and to evaluate the EAggEC probe pCVD432 in identifying EAggEC. METHODS: The Hep-2 cell adhesion assay and colony-blot hybridization assays were carried out for the identification of EAggEC. O:H serotyping, biotyping, antibiogram and plasmid-profile analysis were done. To detect the E. coli LT and ST, ELISA tests were used and, for VT, a vero cell assay was used. RESULTS: EAggEC strains were isolated from 56 out of 115 diarrheal children (48.7%): the organism was present alone and presumed to cause diarrhea in 22 (19.1%) cases. The rest of the cases were associated with two or more diarrheagenic E. coli strains. EAggEC strains were isolated from 25% of total diarrheal children (first day of isolation) and 8.86% of age-matched healthy individuals (p<0.03). This isolation rate was significantly higher than the one found for other diarrheagenic E. coli strains. In parallel, we evaluated the sensitivity and specificity of EAggEC probe pCVD432, and found that it had 56% sensitivity with 100% specificity compared with the Hep-2 cell test. EAggEC isolates were characterized by serotyping, biotyping, antibiotic resistance pattern, plasmid profiling and toxin production analysis. They did not produce any one of these classical toxins and nor did they relate to any particular serotypes. Plasmid analysis of the 79 EAggEC isolates (n=315) showed seven different profiles. Ten resistance patterns were identified and 34 strains were sensitive to all drugs. There was no association between plasmid profiles and antibiotic resistance patterns. All 16 classical E. coli biotypes were found in this small EAggEC population. CONCLUSIONS: EAggEC has been emerging as a cause of childhood diarrhea in African children in Congo. From the accumulated data it was found that there is a great heterogeneity in EAggEC populations.