Neonatal infections with multidrug-resistant ESBL-producing E. cloacae and K. pneumoniae in Neonatal Units of two different Hospitals in Antananarivo, Madagascar

Background

We investigated the molecular mechanism of ß-lactam resistance in extended-spectrum ß-lactamase (ESBL)-producing Enterobacterial strains isolated in neonatal units of different hospitals in Anatnanarivo, Madagascar.

Methods

Bacteria were identified by standard biochemical methods, disc diffusion antibiograms and Etest. Resistance genes were sought by PCR. Strains were characterized by Rep-PCR (Diversilab), plasmid analysis and rep-typing.

Results

From April 2012 to March 2013, 29 ESBL-producing E. cloacae and 15 K. pneumoniae were isolated from blood culture (n = 32) or gastric samples (n = 12) performed at day 0 or 2 from 39/303 newborns suspected of early neonatal infection. These infants were treated with expanded spectrum cephalosporins, due to lack of carbapenems, leading to a high mortality rate (45 %). Isolates recovered were all, but 4, multidrug resistant, particularly to fluoroquinolones (FQ) except for 21 E. cloacae isolates. Isolates produced TEM-1 and CTX-M-15 ß-lactamases and their genes were located on several self-transferable plasmids of variable sizes sizes that could not be linked to a major plasmid incompatibility group. E. cloacae isolates belonged to 6 Rep-types among which two counted for 11 isolates each. The FQ resistant E. cloacae isolates belonged to one clone, whereas the FQ susceptible E. cloacae isolates belonged to four clones. The K. pneumoniae isolates belonged to 9 Rep-types among which one included five isolates.

Conclusion

This study is the first molecular characterization of ESBL-producing isolates from neonatology units in Madagascar, a country with limited epidemiological data. It revealed an important multi-clonal dissemination of CTX-M-15-producing isolates reflecting both the high community carriage and the very early nosocomial contamination of the neonates.

Role of contaminated aspiration tubes in nosocomial outbreak of Klebsiella pneumoniae producing SHV-2 and CTX-M-15 extended-spectrum beta-lactamases

Klebsiella pneumoniae resistant to ceftazidime was isolated from ten neonates hospitalised between February and March 2006 in two Antananarivo hospitals, Madagascar. The main environmental source, for one hospital in particular, was the liquid used to rinse aspiration tubes in the paediatric wards. The risk of contamination from aspiration tubes is very high in the hospitals of Antananarivo since tap water used to rinse the tubes is not regularly changed. Phenotypical (biotyping and antibiotyping) and genotypical (pulsed-field gel electrophoresis) analysis of all the clinical isolates indicated that nine cases were due to a single clone. This clone carried the genes encoding SHV-2 and CTX-M-15 beta-lactamases. This is the first description of an epidemic due to an ESBL-producing member of the family Enterobacteriaceae in Malagasy hospitals.

[Serologic diagnosis of chlamydial and Mycoplasma pneumoniae infections]

The diagnosis of Chlamydia trachomatis infection can be based either on direct detection of the organism or its components or indirectly by measuring antibodies as markers of the individual's response to the infection. The latter is currently of limited value. Neither IgG or IgA antibodies can be used to diagnose current genital infection by Chlamydia trachomatis or to exclude such an infection. There is no solid ground as yet for the use of IgA antibodies as a marker of persistant or unresolved infection. Commercial tests in the Elisa format based on peptides from the MOMP of Chlamydia trachomatis are available and show good specificities and sensitivities. Hsp60 seems to have a unique role in the development of tubal scarring and antibodies to chsp60 could predict tubal factor infertility. Serology is the main diagnostic tool for the diagnosis of Mycoplasma pneumoniae infection. The serologic assays are the complement fixation test (CF), immunofluorescence, the microparticle agglutination and recently EIAs. The CF test is still used for serodiagnosis of Mycoplasma pneumoniae infection because of the sensitivity of 90%. Single titer of >or= 64 are considered to be indicative of recent infection. A number of commercial EIAs have been developped. The difficulty for IgG interpretation is a definition of a cutoff value for discriminating infected and healthy subjects. Most of the IgM assays show good diagnostic sensitivities and are valuable tools for the early diagnosis of Mycoplasma pneumoniae infection in children. There are no wholly satisfactory serological methods for diagnosis of Chlamydia pneumoniae infection. Problems arise from the high background of IgG antibody prevalence, the lack of standardized testing methods.