Achromobacter spp. healthcare associated infections in the French West Indies: a longitudinal study from 2006 to 2016.

BACKGROUND: Bacteria of the Achromobacter genus, more particularly xylosoxidans species, are responsible for various healthcare associated infections (HAI) which are increasingly described since the last decade. Cystic fibrosis (CF) patients are considered as potential reservoirs in hospitals. We performed a retrospective study to estimate the frequencies of Achromobacter spp. HAI among patients from French West Indies, to determine characteristics of infected patients and establish a possible link between CF and infections. METHODS: All adults with at least one Achromobacter spp. positive sample and infection criteria in accordance with European official definitions of HAI, hospitalized in University Hospital of Martinique from 2006 to 2016 for more than 48 h, were included. Patient clinical features, immune status and underlying diseases were obtained from medical files. A list of CF patients was given by clinicians. Antibiotic-susceptibility profiles of the strains were determined using an automated method. RESULTS: Mean incidence density was 0.038/1000 days of hospitalization. Achromobacter spp. HAI evolved as an endemic situation with a low but pretty much stable incidence rate over the 11-year observation period. An epidemic peak was noticed in 2013. Among the 66 included patients, 56.1% were immunocompetent and no one had CF. Pneumonia and bacteraemia were the two main HAI. Among the 79 isolated strains, 92.4% were resistant to at least 1 major antibiotic and 16.4% met the definition of multidrug-resistant bacteria. CONCLUSIONS: This microorganism, little known in our country because of the scarcity of CF patients, represents a threat for both immunosuppressed and immunocompetent patients and a therapeutic challenge because of its high resistance.

Achromobacter xylosoxidans in hospital environments: still waters run deep!

BACKGROUND: Hospital reservoirs of Achromobacter xylosoxidans, responsible for nosocomial infections, are poorly known. METHODS: We examined the growth, survival and biofilm formation of five A. xylosoxidans strains for up to 2 y in distilled, dialysis or microfiltered water. Each strain was inoculated at 102 CFU/ml without adding nutrients. RESULTS: All strains grew at a level of 3x103 to 1.5x107 CFU/ml; each strain showed a preferred water type. Strains isolated from quaternary ammoniums showed the highest ability to grow and form biofilms in nutrient-poor waters. CONCLUSION: Medical waters and notably sterile distilled water bottles appear to be long-lasting reservoirs of A. xylosoxidans.

Achromobacter xylosoxidans resistance to antiseptics and disinfectants is far from obvious.

BACKGROUND: Achromobacter xylosoxidans is described as being resistant to antiseptics and disinfectants. We studied in vitro the ability of five strains to survive and grow in such solutions, with and without starvation. METHODS: Bacterial suspensions in rich media and in distilled water were inoculated into eight antiseptics or disinfectants under conditions of use. RESULTS: All strains from cultures in distilled water survived in aqueous chlorhexidine and only environmental strains survived in a quaternary ammonium-based disinfectant. Survival did not exceed 30 min and no growth was observed. CONCLUSIONS: This study highlights a relationship between starvation and survival in antiseptics and disinfectants.

Evaluation of different serological assays for early diagnosis of leptospirosis in Martinique (French West Indies).

BACKGROUND: Leptospirosis is a potentially life-threatening but curable zoonosis whose prognosis depends on accurate and timely diagnosis. Because of its non-specific clinical presentation, laboratory testing is essential to confirm the diagnosis. Here, we aimed to assess the performance of two enzyme-linked immunosorbent assays (ELISAs) (ELISA Serion and ELISA-Hb Pasteur) and one immunodot (GenBio) using quantitative PCR (qPCR) as gold standard, instead of the traditional microscopic agglutination test, for the diagnosis of acute leptospirosis in an endemic area. METHODOLOGY/PRINCIPAL FINDINGS: Between January 2011 and December 2012, a total of 122 patients were diagnosed with leptospirosis, as confirmed by qPCR at the University Hospital of Martinique. Among them, 103 had at least one serum sample available for analysis. Performance of each serological assay was evaluated according to days' post onset of symptoms (DPO) and local species diversity (which included L. santarosai, L. interrogans, L. kirschneri, L. borgpetersenii, L. noguchii, and L. kmetyi). Several thresholds were tested to optimize accuracy. When considering the manufacturer's threshold, the sensitivity of ELISA Serion, ELISA-Hb Pasteur and GenBio immunodot was 75%, 67% and 64%, while specificity was 92%, 98% and 100%, respectively. Moreover, the threshold optimization allowed a significant improvement in specificity for the ELISA Serion from 92% to 99% (p<0.05). During the first 5 DPO, sensitivities were 35%, 30% and 42% for ELISA Serion, ELISA-Hb Pasteur and GenBio immunodot, respectively. However, between 6─10 DPO, these sensitivities dramatically increased to reach 86%, 76% and 67%, respectively. Performances of the three assays were not affected by the species studied. CONCLUSIONS/SIGNIFICANCE: All these serological assays showed the potential for diagnosing leptospirosis after (but not before) 6 days' post onset of symptoms. In a high prevalence setting, where highest specificities are needed, threshold optimizing should be performed for this purpose.