A new serovar and a new serological variant belonging to Salmonella enterica subspecies diarizonae

SHORT COMMUNICATION

A new serovar and a new serological variant belonging to Salmonella enterica subspecies diarizonae

CA Solari^I; JR Mandarino^I; MHM Panizzutti^II; RHG Farias^II

^ILaboratório de Patologia Clínica, Hospital Universitário Gaffrée e Guinle, Universidade do Rio de Janeiro Rua Mariz e Barros 775 20270-004 Rio de Janeiro, RJ, Brasil

^IIInstituto de Biologia do Exército, Rio de Janeiro, RJ, Brasil

^{Correspondence}

ABSTRACT

Description of a new serovar (S. IIIb 16:k:e,n,x,z₁₅) and a new serological variant (S. IIIb 42:z₁₀:e,n,x,z₁₅:z₆₀ ) belonging to the genus Salmonella isolated from stool specimens of Brazilian snakes (Crotalus durissus).

Keywords:Salmonella - new serovar - new serological variant

The genus Salmonella comprises two species: (1) S. enterica, which is divided into six subspecies: S. enterica subspecies enterica (I), S. enterica subspecies salamae (II), S. enterica subspecies arizonae (IIIa), S. enterica subspecies diarizonae (IIIb), S. enterica subspecies houtenae (IV) and S. enterica subspecies indica (VI); and (2) S. bongori (formely called S. enterica subspecies bongori V). Species and subspecies can be distinguished on the basis of differential characters, and these, through antigenic formulas, into 2,501 serovars. Usually the 1,478 serovars that belong to the enterica species enterica subspecies (I) colonize the enteric tract of warm-blooded animals, while the other 1,023 serovars belonging to subspecies of the II, IIIa, IIIb, IV and VI and to species S. bongori are found in cold-blooded animals and in the environment (Popoff 2001).

Considering the presence of Salmonella in snakes, as previously described (Hinshaw & McNeil 1945, Zwart 1960, Biggland & Fox 1967, Mayer & Frank 1974, Cambreet al. 1980, Onderka & Finlayson 1985, Ackman et al. 1995, Sá & Solari 2001), we established a survey for Salmonella organisms in Brazilian snakes maintained at the ofidarium of the Instituto de Biologia do Exército. One previously unknown serovar and one serological variant belonging to Salmonella IIIb were found.

In our methodology, cloacal swabs from snakes (Crotalus durissus) were introduced in Cary-Blair transport medium (Difco) and pre-enriched in 10 ml of Buffered Peptone Water (Merck) incubated 16-18 h at 37^oC. An aliquot of 0.1 ml was transferred to 10 ml of Rappaport-Vassiliadis (Merck). After incubation at 37^oC for 18 to 24 h, the broth was streaked onto indicative selective media (Hektoen Enteric Agar, Merck). After incubation at 37^oC for 18 to 24 h, three to five colonies suspected of Salmonella, were submitted to preliminary biochemical identification using Triple Sugar Iron Agar, Lysine Iron Agar and Urea Broth (Merck). Strains presenting a biochemical profile suggestive of Salmonella were submitted to additional biochemical tests (Ewing 1986). The strains confirmed as Salmonella were differentiated in species and subspecies (Popoff 2001). Both strains were recognized as belonging to S. enterica subspecies diarizonae (Table).

Before performing the antigenic characterization (rapid slide agglutination), each culture was tested for smooth (S) or rough phase (R) by inspection of suspensions made done in 2% saline solution. Once in the smooth phase, the cultures were serotyped by using Salmonella OH polyvalent antiserum (Fundação Oswaldo Cruz), somatic (O) and flagellar (H) polyvalent antisera and the respective monovalent antisera (Difco and Sanofi-Pasteur) (Popoff 2001). One of the strains (strain no. 4, also denominated as Institut Pasteur 9173/01), isolated from a snake captured in Três Corações, state of Minas Gerais, presented the antigenic formula 42:z₁₀: e,n,x,z₁₅: z₆₀ (triphasic variant). The other strain (strain no. 25, also denominated as Institut Pasteur no. 9192/01) had the antigenic formula 16:k:e,n,x,z₁₅ (new serovar). The new serovar and the new serological variant of S. enterica subspecies diarizonae in the present communication will be included in the next edition (9th) of the Kauffmann-White Scheme.

Acknowledgements

To Dr Michel Y Popoff for the biochemical and serological confirmations of strains. WHO Collaborating Centre for Reference and Research of Salmonella, Institut Pasteur, Paris, France.

Received 12 August 2002

Accepted 30 December 2002

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Publication Dates

• Publication in this collection
  18 Aug 2003
• Date of issue
  June 2003

History

• Accepted
  30 Dec 2002
• Received
  12 Aug 2002