Yersinia enterocolitica, a small, Gram-negative coccobacillus which culturally and biochemically resembles members of the family Enterobacteriaceae, is widespread in nature, particularly in both domestic and wild mammals and birds. Human infection caused by this microorganism has been well documented in Europe, primarily in Scandinavian countries, and is now being increasingly appreciated in the United States, Canada, South Africa, and Japan. Infection with Y. enterocolitica usually presents as acute mesenteric lymphadenitis and terminal ileitis, although gastroenteritis, erythema nodosum, polyarthritis, septicemia, meningitis, cellulitis, conjunctivitis, and subacute localized abscesses in liver and spleen have also been recorded. Beginning with a review of historical milestones since its first description in the U.S. in 1939, this article will endeavor to place into perspective those factors contributing to the recognition and awareness in the U.S. of this long-discounted human pathogen. Pertine...

Yersinia Enterocolitica: A Panoramic View of a Charismatic Microorganism

https://sfamjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2672.1982.tb04838.x

A Review: Yersinia enterocolitica†

Four enrichment procedures were used for examining 131 raw milk samples for the presence of Yersinia enterocolitica. Forty-two isolations were obtained from 19 pooled- (31.1 percent positive) and 10 individual-producer samples (14.3 percent positive). Enrichment by Butterfields phosphate buffer incubated at 4 degrees C for 14 days and then inoculation of modified Rappaport broth incubated at 23 degrees C for 5 days produced the greatest number of isolations. The majority of isolates were biotype 1, and many were atypical from clinical isolates in being rhamnose positive (47.6 percent), citrate positive (16.7 percent), and lactose positive (26.2 percent). Thirteen isolates were serotypable, belonging to seven different O serotypes, with O:5 occurring most frequently.

Isolation of Yersinia enterocolitica from raw milk.

Through transposon mutagenesis and DNA sequence analysis, the main disease determinant of the entomopathogenic bacterium Yersinia entomophaga MH96 was localized to an ~32-kb pathogenicity island (PAI) designated PAI(Ye₉₆). Residing within PAI(Ye₉₆) are seven open reading frames that encode an insecticidal toxin complex (TC), comprising not only the readily recognized toxin complex A (TCA), TCB, and TCC components but also two chitinase proteins that form a composite TC molecule. The central TC gene-associated region (~19 kb) of PAI(Ye₉₆) was deleted from the Y. entomophaga MH96 genome, and a subsequent bioassay of the ΔTC derivative toward Costelytra zealandica larvae showed it to be innocuous. Virulence of the ΔTC mutant strain could be restored by the introduction of a clone containing the entire PAI(Ye₉₆) TC gene region. As much as 0.5 mg of the TC is released per 100 ml of Luria-Bertani broth at 25°C, while at 30 or 37°C, no TC could be detected in the culture supernatant. Filter-sterilized culture supernatants derived from Y. entomophaga MH96, but not from the ΔTC strain grown at temperatures of 25°C or less, were able to cause mortality. The 50% lethal doses (LD₅₀s) of the TC toward diamondback moth Plutella xylostella and C. zealandica larvae were defined as 30 ng and 50 ng, respectively, at 5 days after ingestion. Histological analysis of the effect of the TC toward P. xylostella larva showed that within 48 h after ingestion of the TC, there was a general dissolution of the larval midgut.

The Main Virulence Determinant of Yersinia entomophaga MH96 Is a Broad-Host-Range Toxin Complex Active against Insects

Infections due to biochemically typical Yersinia enterocolitica usually present as gastroenteritis, mesenteric lymphadenitis, terminal ileitis, and septicemia often with visceral abscesses. In these instances, the isolates have been biochemically typical and of well-established serotypes, namely 0:3 or 0:9 and, in the United States, 0:5 or 0:8. The recovery, recognition, and significance of biochemically and serologically atypical Y. enterocolitica in human infections has proceeded more slowly. From an analysis of the clinical histories of 20 patients infected with 21 such aberrant Y. enterocolitica, it appears that these strains are of restricted pathogenic potential, producing various clinical entities such as localized skin abscesses, conjunctivitis, self-limiting enteritis, and wound and urinary tract infections in hosts with predisposing factors. Epidemiologically, whereas episodic acquisition of atypical strains by hospitalized patients is indicative of nosocomial transmission, in the present series sporadic isolations over a 4-year period, mainly from ambulatory patients, suggest an occult reservoir in the community serviced by The Mount Sinai Hospital. In contrast to typical Y. enterocolitica, which has become well adapted in animal and human hosts, it appears that environmental strains may be in the evolutionary process of becoming adapted to humans.

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Atypical Yersinia enterocolitica: clinical and epidemiological parameters.

Clinical isolates of rhamnose-positive Yersinia enterocolitica (Y.e.rh+) were compared with typical rhamnose-negative Y. enterocolitica (Y.e.rh-) and with Yersinia pseudotuberculosis. The Y.e.rh+ differed from the Y.e.rh- and Y. pseudotuberculosis in their ability to ferment raffinose and lactose, utilize citrate and in their inability to grow on Hektoen enteric agar at 22 or 37 C, on Salmonella-Shigella agar at 37 C, and scant on xylose-lysine-deoxycholate agar at 37 C. An extensive temperature-dependent profile of characteristics was established for the Y.e.rh+: motility, acetoin production, citrate utilization, growth on Salmonella-Shigella agar, and ampicillin resistance occurred at 22 C but not 37 C; fermentation of melibiose, raffinose, and cellobiose occurred within 24 h at 22 C, but not before 5 days at 37 C; fermentation of rhamnose and production of beta-galactosidase occurred within 24 h at 22 C, but not before 48 h at 37 C; greater resistance to ampicillin, chloramphenicol, streptomycin, kanamycin, carbenicillin, and gentamicin was observed at 22 than 37 C; and good growth on xylose-lysine-deoxycholate agar occurred at 22 but not 37 C. For optimal recovery of Y.e.rh+ from mixed culture, e.g., stools, two MacConkey plates should be inoculated and incubated, one at 37 C, and one at 22 C. Lactose-negative colonies appearing after 48 h on the 22 C MacConkey agar but not the 37 C MacConkey agar should be considered possible Y.e.rh+. Biochemicals should be tested in duplicate, one set incubated at 22 C, one set at 37 C. Antibiotic susceptibility tests of Y.e.rh+ isolates should be incubated at both 37 C and at a lower temperature to allow the greatest expression of resistance of these organisms to the various antibiotics.

B Chester

Papers

Temperature-dependent cultural and biochemical characteristics of rhamnose-positive Yersinia enterocolitica.