Cystic Fibrosis Bacteria, Recently ID’d, Spread Among Patients at CF Center

Margarida Azevedo, MSc avatar

by Margarida Azevedo, MSc |

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CF bacteria

A new study report for a first time an “epidemic spread” of Pandoraea pulmonicolaa bacterial species that belongs to the recently identified genus Pandoraea spp. and which is associated with cystic fibrosis (CF), among patients at a CF center in France. The article, published in BMC Infectious Diseases, is titled “Epidemic spread of Pandoraea pulmonicola in a cystic fibrosis center.

Pandoraea spp. is a genus of non-fermentative aerobic Gram negative bacteria first described in 2000, with the identification of five bacterial species (Pandoraea apista, Pandoraea pulmonicolaPandoraea pnomenusaPandoraea sputorum and Pandoraea norimbergensis). Four more species (Pandoraea thiooxidans, Pandoraea oxalativorans, Pandoraea faecigallinarum and Pandoraea vervacti) and another four unnamed ones have been described. In humans, Pandoraea spp. has been mainly isolated in CF patients, and certain species, such as P. apista, have been found in CF patients with increasing frequency, possibly representing an emerging pathogen for chronic lung colonization in this population. Such infections lead to pulmonary exacerbations and consequent decline of lung function, possibly resulting in pulmonary dysfunction.

Researchers are reporting the spread of P. pulmonicola to 6 of the 243 CF patients at the Centre Hospitalier Universitaire de Nice from 2009, and the clinical impact of the infection in these patients. Several clinical parameters were assessed, such as age, sex, type of CFTR mutations (a defective gene in CF), date of first P. pulmonicola isolation, presence of other pathogens, best forced expiratory volume in one second (FEV1) value per year, number of intravenous antibiotic courses per year, clinical status and outcome, and transplantation. Bacterial identification was carried out in samples collected from the patients through a series of genetic analyses and sequencing techniques.

The team hypothesized that the bacteria was spread through droplet cross-transmission, due to incorrect preventive measures. The samples recovered were found to be resistant to the antibiotics beta-lactams, ciprofloxacin and colistin, but susceptible to sulfamethoxazole. All the patients were chronically colonized with both P. pulmonicola, which is consistent with previous reports of this bacteria’s ability to chronically colonize CF lungs, and Pseudomonas aeruginosa. Due to this co-infection, it is difficult to determine the exact role of P. pulmonicola in the lung function decline observed. Three of the patients analyzed have died.

The researchers highlighted the need for preventive measures, concluding, “Our study notes the role of P. pulmonicola as an emerging pathogen that can cause chronic lung colonization in CF patients. Identification tools need to be accurate and must be based on molecular techniques and MALDI-TOF MS. Cross-transmission preventive measures also need to be strictly followed to avoid an epidemic spread. Hopefully, the use of whole genome sequencing will provide significant additional information concerning the virulence of P. pulmonicola.”