Assessment of antibiotic susceptibility of <i>Legionella pneumophila</i> isolated from water systems in Poland

Abstract

obtained from water systems in public buildings in Poland were tested. Susceptibility testing was performed using the E-test method. The tested antibiotic were azithromycin, ciprofloxacin, and rifampicin. The medium used for the susceptibility testing was BCYE-, a special medium for Legionella cultivation. Results. Among the tested strains, L. pneumophila was the only one resistant to azithromycin. It was a strain of L. pneumophila SG 2-14 isolated from the water system in a sanitorium. All isolates were found to be sensitive to ciprofloxacin and rifampicin. However, the azithromycin-resistant strain exhibited higher ciprofloxacin and rifampicin MIC (1.5 μg/ml, and 0.19 μg/ml, respectively). The MIC 50 for azithromycin, ciprofloxacin, and rifampicin were 0,032, 0,125, and 0,003 μg/ml, respectively. The MIC 90 for azithromycin, ciprofloxacin, and rifampicin were 0,032, 0,125, and 0,003 μg/ml, respectively. Conclusions. Azithromycin resistance was found in one strain of L. pneumophila SG 2-14, but the resistance mechanism is unknown and needs further study. It is possible that therapeutic failures in Legionnaires' disease may be associated with bacterial resistance which should be taken into account. The antibiotic sensitivity testing described in this study could be helpful in detecting the resistance of clinical L. pneumophila isolates. Ciprofloxacin and rifampicin have good in vitro activity against environmental L. pneumophila SG 1 and SG 2-14 in Poland.

Antibiotic Resistance of Legionella pneumophila in Clinical and Water Isolates—A Systematic Review

“…Xiong et al have reported the increased effectiveness of levofloxacin [ 45 ], followed by minocycline and doxycycline. The effectiveness of quinolones—ciprofloxacin, this time—was recorded in a later study by Sikora A. et al [ 46 ]. Contrary to these findings, it was Sharaby et al [ 30 ] who revealed some slight resistance against quinolones but an effectiveness of doxycycline, clarithromycin, rifampicin and trimethoprim sulphamethoxazole (SXT).…”

“…In 8/89 (9%) of the articles, the authors used the Kirby–Bauer method and followed the protocol proposed by the CLSI ( Table S1 raw data; [ 82 , 83 ]) or older citations ( Table S1 raw data; [ 40 , 84 ]). Finally, there were 9/89 (10%) articles that applied a combination of the methods ( Table S1 raw data; [ 42 , 46 , 56 , 65 , 85 , 86 , 87 , 88 , 89 ]) and one multi-center study from Dunbar et al 2007 [ 90 ]. In the Dunbar et al [ 90 ] study, they performed an alternative Broth Microdilution method (Sensititre microtitre plates containing freeze-dried antimicrobial agents) in order to evaluate the activity of telithromycin against a worldwide L. pneumophila isolate set.…”

“…This arises from the fact that the acquisition of a suitable specimen from a patient before the administration of antibiotics is not always feasible [ 38 ]. Combined with this, there is always the issue of antibiotic inactivation (examples are tetracyclines, fluoroquinolones, and macrolides) due to the presence of charcoal in the medium, which is necessary for the proliferation of Legionella [ 28 , 29 , 42 , 43 , 46 , 47 ]. Moreover, the results obtained from each study should be interpreted with caution since in certain circumstances, the in vitro results may poorly correlate with the clinical effectiveness [ 42 ] of each antibiotic.…”

Water as a Source of Antimicrobial Resistance and Healthcare-Associated Infections

“…Of those that specifically investigated Legionella spp., two studies referenced the International Organization for Standardization (ISO) 11731—water quality enumeration of Legionella [ 31 , 36 ]. One study investigating L. pneumophila followed Italian guidelines for prevention and the control of legionellosis [ 34 ] and two studies used other culturing techniques [ 35 , 44 ]. Of the studies investigating P. aeruginosa, four papers used membrane filtration methods followed by plating onto selective media such as R2A, cetrimide, and Columbia with horse blood, one of which referenced the ISO 16266:2008—detection and enumeration of P. aeruginosa specifically [ 38 , 39 , 43 , 48 ].…”

Frequency of use of terminal points as an important risk factor for Legionella colonization in hospitals

“…The incidence of nosocomial infections is very low (7), but it represents a major public health concern mainly because nosocomial cases occur in a significant proportion in patients without any specific risk factor, and also due to the high lethality (50% in the Valencian Community, Spain). (8,9) The presence of bacteria in water is considered a prerequisite for infection (10,11). The growth of Legionella depends on several factors, among others, pH and hardness of the water, presence of old pipes, standing water, difficulty in maintaining the right temperature, biofilm formation, and the pipe length as an indirect factor (12) (13).…”