Isolement de Methylobacterium podarium au cours d’une inflammation intraoculaire

The Family Methylobacteriaceae

“…Methylobacterium strains have been increasingly reported as infectious agents in humans (Borsali et al 2011;Holton et al 1990;Lambert et al 1983;Sanders et al 2000;Truant et al 1998), with 30 clinical cases reviewed by Sanders et al (2000). Clinically recovered Methylobacterium strains are typically regarded as opportunistic pathogens in immunocompromised patients, such as those on chemotherapy (Engler and Norton 2001;Sanders et al 2000), and with immunosuppression due to alcoholism, renal failure, diabetes, tuberculosis, or (uncommonly) from patients with no previous underlying clinical condition (Gilardi and Faur 1984;Lai et al 2011;Lambert et al 1983;Liu et al 1997;Strazzi et al 1992;Truant et al 1998).…”

“…Clinically recovered Methylobacterium strains are typically regarded as opportunistic pathogens in immunocompromised patients, such as those on chemotherapy (Engler and Norton 2001;Sanders et al 2000), and with immunosuppression due to alcoholism, renal failure, diabetes, tuberculosis, or (uncommonly) from patients with no previous underlying clinical condition (Gilardi and Faur 1984;Lai et al 2011;Lambert et al 1983;Liu et al 1997;Strazzi et al 1992;Truant et al 1998). Symptoms due to Methylobacterium infections range from bacteremia, fever, sepsis, empyema, pneumonia, peritonitis, to eye or urinary tract infection (Borsali et al 2011;Brown et al 1996;Fernandez et al 1997;Furuhata et al 2006;Hiraishi et al 1995;Lee et al 2004;Sanders et al 2000).…”

“…A frequent isolate from infected patients has been Mtb mesophilicum (Engler and Norton 2001;Holton et al 1990;Kaye et al 1992;Sanders et al 2000), which has also been shown as the cause of a postoperative septicemia case (Barriere et al 2008). Other species (including Mtb radiotolerans, Mtb aminovorans, Mtb thiocyanatum, Mtb extorquens, Mtb zatmanii, Mtb fujisawaense, Mtb lusitanum, and Mtb podarium) have also been reported (Borsali et al 2011;Fanci et al 2010;Furuhata et al 2006;Hornei et al 1999;Lai et al 2011;Truant et al 1998), with Mtb extorquens earning the clinical nickname ''the red phantom'' (Holton et al 1990). It has been suggested that infection rates may be underestimated because of the difficulty of identifying Methylobacterium strains which grow only slowly on commonly used clinical media (Hornei et al 1999), and underreporting of infection by Methylobacterium species due to difficulties in identification using standard clinical practices (Blomqvist et al 1997; Lee et al 2004).…”

“…This link was probed by Borsali et al (2011) in considering the diagnostic difficulty of relating the presence of Mtb podarium to the eye infection reported by them. It is not simple to consider the Methylobacterium case in terms of Koch's postulates: The first postulate (''The microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy organisms'') was abandoned as a universal rule by Koch on discovering asymptomatic carriers of cholera and typhoid fever, and asymptomatic carriers are now known to be a common feature of many infectious diseases, and could be the case for the commensal strains of Methylobacterium.…”

“…In one example, intervention with five antibiotics was needed to cure the infection (Hornei et al 1999). Aminoglycoside antibiotics (imipenem, ticarcillin-clavulanic acid, sulfamethoxazole, and trimethoprim), tetracycline, rifamycin, and gentamycin have been reported to be effective against Methylobacterium, but a number of studies have shown resistance of some strains to antibiotics, including cephalosporins, ampicillin, piperacillin, carbenicillin, spectinomycin, puromycin, cefuroxime, erythromycin, vancomycin, chloramphenicol, fosfomycin, piperacillin, cefazolin, cefotetan, cerfuroxime, ceftazidime, ceftriaxone, ciprofloxacin, meropenem, nalidixic acid, teicoplanin, gentamycin, amikacin, nitrofurantoin, and p-fluorophenylalanine (Borsali et al 2011;Brown et al 1992;Furuhata et al 2006;Goodwin et al 1988;Korvick et al 1989;Lee et al 2004;Zaharatos et al 2001). Brown et al (1992) showed the majority of 15 clinical isolates of Methylobacterium were resistant to b-lactam drugs, with the exceptions of ceftriaxone and ceftizoxime, and that six of these were b-lactamase-negative with a minimum inhibitory concentration for ampicillin of 4 mg ml À1 , whereas nine b-lactamase-positive isolates were resistant to 8-32 mg ml À1 (or more).…”