Print version ISSN 0036-4665
Rev. Inst. Med. trop. S. Paulo vol.50 no.5 São Paulo Sept./Oct. 2008
LETTER TO THE EDITOR
Macarena Pariente MartínI; Elena Escribano GaraizábalII,*; Pedro Jorge Liria SánchezIII; María Dolores Crespo SánchezIV
ILaboratorio de Microbiología Complejo Hospitalario Universitario de Albacete C/ Hermanos Falcó, 37; 02006 Albacete. Spain Tel. 967597507; E-mail: firstname.lastname@example.org
IILaboratorio de Microbiología Complejo Hospitalario Universitario de Albacete C/ Hermanos Falcó, 37; 02006 Albacete. Spain Tel. 967597507; E-mail: email@example.com
IIIServicio de Cirugia Plástica y Reparadora Complejo Hospitalario Universitario de Albacete C/ Hermanos Falcó, 37; 02006 Albacete. Spain Tel. 967597994; E-mail: firstname.lastname@example.org
IVLaboratorio de Microbiología Complejo Hospitalario Universitario de Albacete C/ Hermanos Falcó, 37; 02006 Albacete. SpainTel. 967597507; E-mail: email@example.com
Albacete, July 23, 2008
Vibrio metschnikovii is a gram-negative bacillus that can be found in various aquatic habitats including fresh, brackish and marine waters and sewage, as well as shellfish, birds, poultry and domestic ungulates2,3,7. The first case of infection in humans was published in 19816 and very few cases have been reported since then. We did not find any reference to the isolation of V. metschnikovii in Spain. We report a case where V. metschnikovii was isolated from an infected ulcer in the leg.
The patient was a 49-year-old woman from Uruguay who had been living in our country for five months, with a 7-year history of fibromyalgia and frequently infected leg ulcers. She came to our hospital´s emergency service suffering from painful ulcers in both legs, which carried a chronic lymphoedema background. Swabs with exudates from ulcers were sent to the laboratory for microbiological study and a regular cure was prescribed. Mixed flora - consisting of multiresistant bacterial organisms - was isolated from both legs. In addition, V. metschnikovii was isolated from the left lower limb. This microorganism formed grey colonies (diameter: 2-3 mm) with complete hemolysis on blood agar after 24 hours of incubation at 36 °C. It formed lactose positive colonies on MacConkey agar and yellowish ones on thiosulfate-citrate-bile salts-sucrose agar. Gram staining of the colonies showed curved gram-negative rods. It was oxidase negative and did not reduce nitrate to nitrite. This strain was identified as V. metschnikovii with a Vitek 2 GN card (bioMérieux) and ID 32 E gallery (bioMérieux), and was confirmed by sequencing the 16S rRNA gene at the National Center for Microbiology. The strain was resistant to amoxicillin (MIC >16 µg/mL), cefalotine (MIC > 8), cefotaxime (MIC = 8), gentamycin (MIC > 8), tobramycin (MIC > 8), and sensitive to cefoxitin (MIC < 8), amikacin (MIC = 16), amoxicillin / clavulanic acid (MIC < 4/2), imipenem (MIC < 1), ciprofloxacin (MIC < 0, 12) and trimethoprim / sulfamethoxazole (MIC < 2/38). The agar diffusion test with combined disks for the detection of extended spectrum β-lactamases was positive. One month after and following an initial improvement, the patient was admitted because of an increased pain and exudation from her ulcers, where multiresistant mixed flora was isolated without the presence of V. metschnikovii. A 16-day course of intravenous antibiotic therapy with imipenem and amikacina, as well as daily cures, was prescribed. The patients showed a good clinical outcome with a progressive decrease of pain and exudation, and improvement of inflammatory analytical parameters.
The isolation of V. metschnikovii from human clinical samples is very rare. Only four cases of bacteremia in adults4-6 and one neonatal sepsis9, a postoperative wound infection in a leg7 and one case of pneumonia10 have been reported. It has also been isolated from the urine of two patients3, from an ulcer in the foot3, from the feces of five children suffering from watery diarrhea1 and in pure culture from the feces of a patient with diarrhea8. The source of infection could not be documented in any of the cases, but presumably the transmission was due to direct contact with the aquatic environment, consumption of contaminated food or manipulation of meat products6,7. The pathogenicity of this bacterium has not been clearly defined. A specific cytolysin with hemolytic properties could be a virulence factor of this microorganism8. The isolation of the bacterium from blood samples and the deadly result in one of the patients seem to confirm its pathogenicity in some cases4, but its etiological role as a cause of diarrhea has not been shown3. In our case it is not possible to establish the clinical significance of the isolation of V. metschnikovii since it was obtained from a surface sample and mixed flora. However it is interesting to note that this bacterium has been isolated in three more cases from lesions in lower limbs3,4,7. Finally, it is noteworthy that the strain isolated in our case was resistant to cefalotine, cefotaxime and gentamicin, which is unusual in this organism1,3,5,7-10.
1. DALSGAARD, A.; ALARCON, A.; LANATA, C.F. et al. - Clinical manifestations and molecular epidemiology of five cases of diarrhoea in children associated with Vibrio metschnikovii in Arequipa, Peru. J. med. Microbiol., 45: 494-500, 1996. [ Links ]
2. FARMER III, J.J.; HICKMAN-BRENNER, F.W.; FANNING, G.R.; GORDON, C.M. & BRENNER, D.J. - Characterization of Vibrio metschnikovii and Vibrio gazogenes by DNA-DNA hybridization and phenotype. J. clin. Microbiol., 26: 1993-2000, 1988. [ Links ]
3. FARMER III, J.J.; JANDA, J.M. & BIRKHEAD, K. - Vibrio. In: Murray, P.R.; Baron, E.J.; Jorgensen, J.H.; Pfaller, M.A. & YOLKEN, R.H., ed. Manual of clinical microbiology. 8. ed. Washington, American Society for Microbiology, 2003. p. 706-718. [ Links ]
4. HANSEN,W.; FRENEY, J.; BENYAGOUB, H. et al. - Severe human infections caused by Vibrio metschnikovii. J. clin. Microbiol., 31: 2529-2530, 1993. [ Links ]
5. HARDARDOTTIR, H.; VIKENES, K.; DIGRANES, A.; LASSEN, J. & HALSTENSEN, A. - Mixed bacteremia with Vibrio metschnikovii in a 83-year-old female patient. Scand. J. infect. Dis., 26: 493-494, 1994. [ Links ]
6. JEAN-JACQUES, W.; RAJASHEKARAIAH, K.R.; FARMER III, J.J. et al. - Vibrio metschnikovii bacteremia in a patient with cholecystitis. J. clin. Microbiol., 14: 711-712, 1981. [ Links ]
7. LINDE, H.J.; KOBUCH, R.; JAYASINGHE, S. et al. - Vibrio metschnikovii, a rare cause of wound infection. J. clin. Microbiol., 42: 4909-4911, 2004. [ Links ]
8. MIYAKE, M.; HONDA, T. & MIWATANI, T. - Purification and characterization of Vibrio metschnikovii cytolysin. Infect. Immun., 56: 954-960, 1988. [ Links ]
9. PRASAD, R.H.V. & KHARIDEHAL, N. - Vibrio metschnikovii sepsis in a Neonate. Internet J. Pediat. Neonatol., 6 (1), 2006. [ Links ]
10. WALLET, F.; TACHON, M.; NSEIR, S.; COURCOL, R.J. & ROUSSEL-DELVALLEZ, M. - Vibrio metschnikovii pneumonia. Emerg. infect Dis., 11: 1641-1642, 2005. [ Links ]
* Correspondence to: Elena Escribano Garaizábal