Multidrug resistant clinical isolates of Pseudomonas aeruginosa are highly susceptible to bacteriophages


Sopio Tsertsvadze1, Tamar Kokashvili2, Nino Lashkhi2, Marina Darsavelidze2, Tamar Suladze2, Ana Giorgobiani1, Ana Tskhvediani2, Nino Janelidze2, George Tsertsvadze2, Eric Valade3, Marina Tediashvili2

1M. Iashvili Children’s Central Hospital, Tbilisi, Georgia, Tbilisi, Georgia
2George Eliava Institute of Bacteriophages, Microbiology and Virology, Tbilisi, Georgia
3Institut de Recherche Biomédicale des Armées (IRBA),, Bretigny Sur Orge, France


Nonfermenting gramnegative bacilli (NFGNB), primarily Pseudomonas aeruginosa, are important health care associated pathogens with high potential for horizontal spread. The outbreaks of related hospital infections are frequent while their elimination remains difficult because of intrinsic resistance to many antibiotics. Bacteriophages have been considered as effective and safe tool for control of multidrug resistant bacterial infections.
This study was undertaken to identify frequency of isolation of P. aeruginosa in the respiratory department with ICU at a large children’s hospital, and to analyze antibiotic and phage susceptibility profiles of isolates. Various samples from patients and fomites (bronchoalveolar lavage, sputum, tracheostome and throat swabs, suction devices, beddings etc) were collected during 6 months period. The isolated cultures of NFGNB were identified using API20NE system followed by PCR confirmation. The susceptibility to 18 antibiotics was determined by disc diffusion method, phage susceptibility - by spot test on solid media. For comparison, studies included P. aeruginosa strains isolated in the same period from patient’s samples collected at the Eliava Diagnostic Center (EDC).
Out of 102 GN bacterial isolates collected at the children’s hospital, 48 isolates were attributed to NFGNB with P. aeruginosa most frequently isolated (27 strains). All P. aeruginosa clinical isolates were multidrug resistant, susceptible only up to 5 antibiotics, mainly ciprofloxacin and tobramycin. Considerably higher susceptibility to antibiotics demonstrated P.aeruginosa isolates (25) obtained from EDC. Two sets of P. aeruginosa isolates (52 strains) were screened against “Pyophage”, “ Intestiphage” and 52 phages from Eliava collection, including 22 newly isolated and characterized phages. The high total lytic efficacy (91.4 % ) of Pae phages towards P. aeruginosa multidrug resistant clinical isolates was demonstrated. Sixteen phages with different lytic spectrum were selected for preliminary subtyping of P. aeruginosa isolates, 8 phages with broad host range – for further infection control in hospitals.
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Reference:
Posters Day 2-T03-Pos-14
Session:
Posters Covering Ecology, Host population control, Co-Evolutionary dynamics and Subversion/Evasion of Host Defences
Presenters:
Marina Tediashvili
Session:
Day 2 Posters Covering: Ecology, Host population control, Co-evolutionary dynamics and Subversion/Evasion of host defences
Presentation type:
Poster presentation
Room:
Poster Halls
Date:
Tuesday, 19 July 2016
Time:
12:05 - 15:00