Resistance of different Chlamydia-like organisms to quinolones and mutations in the quinoline resistance-determining region of the DNA gyrase A- and topoisomerase-encoding genes

Casson, Nicola; Greub, Gilbert

doi:10.1016/j.ijantimicag.2006.03.009

Cited by 31 publications

(20 citation statements)

References 20 publications

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“…Several studies have reported that parachlamydial DNA was detected by PCR in mononuclear cells of sputa and in bronchoalveolar lavage samples from a patient with bronchitis (10). Other studies have suggested that P. acanthamoebae may cause inhalation pneumonia and be responsible for hospital-acquired pneumonia in HIV-infected patients and organ transplant recipients receiving immunosuppressive therapy (7,8,14). Thus, P. acanthamoebae, presumably spreading through amoebae, is emerging as a potential etiological agent of hospital-acquired pneumonia.…”

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confidence: 99%

“…The emergence of P. acanthamoebae as a novel pathogenic agent of respiratory tract infections in hospital environments has important implications for preventing and controlling hospital-acquired diseases (3,8,9,10,14). Several in vitro studies have shown that P. acanthamoebae grew and multiplied in free-living Acanthamoeba amoebae, which are distributed in a broad range of natural environments but also in the water systems of hospitals (1,(12)(13)(14)(15).…”

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confidence: 99%

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Impact of Free-Living Amoebae on Presence of Parachlamydia acanthamoebae in the Hospital Environment and Its Survival In Vitro without Requirement for Amoebae

et al. 2010

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Parachlamydia acanthamoebae is an obligately intracellular bacterium that infects free-living amoebae and is a potential human pathogen in hospital-acquired pneumonia. We examined whether the presence of P. acanthamoebae is related to the presence of Acanthamoeba in an actual hospital environment and assessed the in vitro survival of P. acanthamoebae. Ninety smear samples were collected between November 2007 and March 2008 (trial 1, n ‫؍‬ 52) and between October 2008 and February 2009 (trial 2, n ‫؍‬ 38) from the floor (dry conditions, n ‫؍‬ 56) and sink outlets (moist conditions, n ‫؍‬ 34) of a hospital. The prevalences of P. acanthamoebae DNA in the first and second trials were 64.3% and 76%, respectively. The prevalences of Acanthamoeba DNA in the first and second trials were 48% and 63.1%, respectively. A statistical correlation between the prevalence of P. acanthamoebae and that of Acanthamoeba was found (trial 1, P ‫؍‬ 0.011; trial 2, P ‫؍‬ 0.022), and that correlation increased when samples from just the dry area (floor smear samples, P ‫؍‬ 0.002) were analyzed but decreased when samples from a moist area were analyzed (P ‫؍‬ 0.273). The in vitro experiment showed that, without Acanthamoeba, P. acanthamoebae could not survive in dry conditions for 3 days at 30°C or 15 days at 15°C. Thus, both organisms were coincidentally found in an actual hospital environment, with the presence of Acanthamoeba having a significant effect on the long-term survival of P. acanthamoebae, suggesting that this potential human pathogen could spread through a hospital environment via Acanthamoeba.

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confidence: 99%

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confidence: 99%

Impact of Free-Living Amoebae on Presence of Parachlamydia acanthamoebae in the Hospital Environment and Its Survival In Vitro without Requirement for Amoebae

et al. 2010

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“…Several studies have reported that parachlamydial DNA was detected by PCR in mononuclear cells of sputa and in bronchoalveolar lavage samples of a patient with bronchitis (16,49). Other studies have suggested that P. acanthamoebae might be an agent of community-acquired pneumonia in human immunodeficiency virus-infected patients and in organ transplant recipients receiving immunosuppressive therapy (10,11). P. acanthamoebae might also be a common agent of inhalation pneumonia (23,24).…”

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confidence: 99%

Novel Parachlamydia acanthamoebae Quantification Method Based on Coculture with Amoebae

Matsuo¹,

Hayashi²,

Nakamura

et al. 2008

Appl Environ Microbiol

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Parachlamydia acanthamoebae, belonging to the order Chlamydiales, is an obligately intracellular bacterium that infects free-living amoebae and is a potential human pathogen. However, no method exists to accurately quantify viable bacterial numbers. We present a novel quantification method for P. acanthamoebae based on coculture with amoebae. P. acanthamoebae was cultured either with Acanthamoeba spp. or with mammalian epithelial HEp-2 or Vero cells. The infection rate of P. acanthamoebae (amoeba-infectious dose [AID]) was determined by DAPI (4,6-diamidino-2-phenylindole) staining and was confirmed by fluorescent in situ hybridization. AIDs were plotted as logistic sigmoid dilution curves, and P. acanthamoebae numbers, defined as amoeba-infectious units (AIU), were calculated. During culture, amoeba numbers and viabilities did not change, and amoebae did not change from trophozoites to cysts. Eight amoeba strains showed similar levels of P. acanthamoebae growth, and bacterial numbers reached ca. 1,000-fold (10 9 AIU preculture) after 4 days. In contrast, no increase was observed for P. acanthamoebae in either mammalian cell line. However, aberrant structures in epithelial cells, implying possible persistent infection, were seen by transmission electron microscopy. Thus, our method could monitor numbers of P. acanthamoebae bacteria in host cells and may be useful for understanding chlamydiae present in the natural environment as human pathogens.

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“…Interestingly, P. acanthamoebae is, like W. chondrophila, resistant to fluoroquinolones (3,18). The resistance to fluoroquinolones was also observed for other Chlamydia-related bacteria, including Neochlamydia hartmanellae and Simkania negevensis (3). In the latter study, quinolone resistance in these amoeba-resisting bacteria could be explained by mutations in the quinolone resistance-determining regions (QRDR) of the DNA gyrase A (GyrA)-and topoisomerase IV (ParC)-encoding genes.…”

mentioning

confidence: 78%

“…However, unlike W. chondrophila, both of these chlamydiae are susceptible to quinolones (13,14,19,20,22). Interestingly, P. acanthamoebae is, like W. chondrophila, resistant to fluoroquinolones (3,18). The resistance to fluoroquinolones was also observed for other Chlamydia-related bacteria, including Neochlamydia hartmanellae and Simkania negevensis (3).…”

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confidence: 94%

Antibiotic Susceptibility of Waddlia chondrophila in Acanthamoeba castellanii Amoebae

Goy

Greub

2009

Antimicrob Agents Chemother

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Resistance of different Chlamydia-like organisms to quinolones and mutations in the quinoline resistance-determining region of the DNA gyrase A- and topoisomerase-encoding genes

Cited by 31 publications

References 20 publications

Impact of Free-Living Amoebae on Presence of Parachlamydia acanthamoebae in the Hospital Environment and Its Survival In Vitro without Requirement for Amoebae

Impact of Free-Living Amoebae on Presence of Parachlamydia acanthamoebae in the Hospital Environment and Its Survival In Vitro without Requirement for Amoebae

Novel Parachlamydia acanthamoebae Quantification Method Based on Coculture with Amoebae

Antibiotic Susceptibility of Waddlia chondrophila in Acanthamoeba castellanii Amoebae

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