Salmonella enterica subspecies arizonae infection of adult patients in Southern Taiwan: a case series in a non-endemic area and literature review.

BACKGROUND: The majority of Salmonella arizonae human infections have been reported in southwestern United States, where rattlesnake-based products are commonly used to treat illness; however, little is known in non-endemic areas. We reviewed and analyzed the clinical manifestations and treatment outcomes in adult patients with S. arizonae infection at our institution. METHOD: A retrospective study was conducted at a regional teaching hospital in southern Taiwan from July 2007 to June 2014. All adult patients diagnosed with S. arizonae infections and treated for at least three days at Chia-Yi Christian Hospital were included. Patients were followed till discharge. RESULTS: A total of 18 patients with S. arizonae infections (median age: 63.5 years) were enrolled for analysis, of whom two thirds were male. The three leading underlying diseases were diabetes mellitus, peptic ulcer disease and malignancy. Ten patients had bacteraemia and the most common infection focus was the lower respiratory tract. Most of the patients (72.2%) received third-generation cephalosporins as definitive therapy. In contrast, ampicillin-based regimens (accounting for 45.2%) were the major treatment modalities in previous reports. The crude in-hospital mortality was 5.6%, which was much lower than what was previously reported (22.7%). CONCLUSIONS: Though uncommon, there were cases of S. arizonae infections in Taiwan. Patients receiving third-generation cephalosporins treatment had better prognosis compared with those treated with ampicillin-based regimen.

Subspecies IIIa and IIIb Salmonellae are defective for colonization of murine models of salmonellosis compared to Salmonella enterica subsp. I serovar typhimurium.

Non-subspecies I salmonellae are commensals of cold-blooded vertebrates and cause sporadic disease in mammals. The reasons why non-subspecies I salmonellae do not circulate in populations of warm-blooded vertebrates, but instead only cause occasional disease in this niche, are unknown. We examined the ability of Salmonella enterica subsp. IIIa (subsp. arizonae) and subsp. IIIb (subsp. diarizonae) isolates to grow competitively with subspecies I (serovar Typhimurium) ATCC 14028 in vitro, to colonize Salmonella-sensitive BALB/c mice, and to persist in the intestine of Salmonella-resistant CBA/J mice in competitive infections. Subspecies IIIa had severely reduced intestinal colonization, intestinal persistence, and systemic spread in mice. Subspecies IIIa is nonmotile on swarming agar and thus may also have reduced motility under viscous conditions in vivo. Surprisingly, subspecies IIIb colonizes the intestinal tract of BALB/c mice normally yet does not spread systemically. Subspecies IIIb colonization of the intestine of CBA/J mice is reduced late in infection. In order to understand why these isolates do not colonize systemic sites, we determined that subspecies IIIa and IIIb are not internalized well and do not replicate in J774-A.1 murine macrophages, despite normal adherence to these cells. We further show that selected effectors of both type III secretion systems 1 and 2 are secreted by subspecies IIIa and IIIb in vitro but that each of these isolates secretes a different combination of effectors. We outline the phenotypic differences between these subspecies and subspecies I and provide a possible explanation for the inability of these strains to spread systemically in murine models.

Respiratory and digestive lesions caused by Salmonella arizonae in two snakes.

Cases of diphtheritic necrotizing gastritis in a Rosy Boa (Lichanura trivirgata) and of necrotizing tracheitis in a double-headed Kingsnake (Lampropeltis hondurensis), both associated with Salmonella arizonae, are described. An immunoperoxidase technique indicated that S. arizonae played a role in the causation of the lesions. In addition, the study showed the value of the technique for the detection of S. arizonae in the tissues of infected snakes.

[Salmonella osteomyelitis in a child with sickle cell disease]. / Salmonella-osteomyelitis bij een patiëntje met sikkelcelanemie.

In an eight-months-old girl with sickle cell disease, osteomyelitis due to Salmonella arizona was diagnosed. Osteomyelitis caused by Salmonella species is rare in children. However, in patients with sickle cell disease it is the responsible pathogen in more than 50% of cases. The differentiation between, the much more common, bone crisis and osteomyelitis in sickle cell patients is often difficult. Ultrasound and bone marrow scans may be helpful. It is not known why Salmonella causes osteomyelitis in patients with sickle cell disease. What is clear, however, is that osteomyelitis usually occurs shortly after a preceding bone crisis. Empiric antibiotic treatment of osteomyelitis in patients with sickle cell disease should include coverage for Salmonella species. The patient described was initially treated with cefuroxime and gentamicin, but once the culture result was known this was switched to amoxicillin. As new infection foci later occurred in the bone the treatment was switched to ceftriaxone i.v. which was later substituted by ciprofloxacin orally. With this all of the skeletal abnormalities were fully corrected.

Net replication of Salmonella enterica serovars Typhimurium and Choleraesuis in porcine intestinal mucosa and nodes is associated with their differential virulence.

Salmonella enterica is a facultative intracellular pathogen of worldwide importance and causes a spectrum of diseases depending on serovar- and host-specific factors. Oral infection of pigs with S. enterica serovar Typhimurium strain 4/74 produces acute enteritis but is rarely fatal, whereas serovar Choleraesuis strain A50 causes systemic disease with a high mortality rate. With a porcine ligated ileal loop model, we observed that systemic virulence of serovar Choleraesuis A50 is not associated with enhanced intestinal invasion, secretory responses, or neutrophil recruitment compared to serovar Typhimurium 4/74. The net growth in vivo of serovar Choleraesuis A50 and serovar Typhimurium 4/74 was monitored following oral inoculation of pigs with strains harboring pHSG422, which exhibits temperature-sensitive replication. Analysis of plasmid partitioning revealed that the enteric virulence of serovar Typhimurium 4/74 relative to that of serovar Choleraesuis A50 is associated with rapid replication in the intestinal wall, whereas systemic virulence of serovar Choleraesuis A50 is associated with enhanced persistence in intestinal mesenteric lymph nodes. Faster replication of serovar Typhimurium, compared to that of serovar Choleraesuis, in the intestinal mucosa was associated with greater induction of the proinflammatory cytokines tumor necrosis factor alpha, interleukin-8 (IL-8), and IL-18 as detected by reverse transcriptase PCR analysis of transcripts from infected mucosa. During replication in batch culture and porcine alveolar macrophages, transcription of genes encoding components of type III secretion systems 1 (sipC) and 2 (sseC) was observed to be significantly higher in serovar Typhimurium 4/74 than in serovar Choleraesuis A50, and this may contribute to the differences in epithelial invasion and intracellular proliferation. The rapid induction of proinflammatory responses by strain 4/74 may explain why pigs confine serovar Typhimurium infection to the intestines, whereas slow replication of serovar Choleraesuis may enable it to evade host innate immunity and thus disseminate by stealth.

Enterotoxigenicity and invasiveness of Salmonella species.

A large number of enterotoxigenic strain was encountered in a group 56 Salmonella cultures belonging to 8 species viz., S. alachua, S. anatum, S. dublin, S. Enteritidis, S. hindmarsh, S. newport, S. typhimurium, S. weltevreden, and 5 serotypes of S. arizona (16:z4:--; 48:1,v:z56; 53:z52:z53; 60:r:z; 60:i:z53). These cultures were isolated mainly from humans and animals suffering from gasteroenteritis. The enterotoxigenic (diarrhoeagenic) Salmonella cultures possess capacities for both skin permeation and epithelial penetration (invasiveness). Preliminary characterization revealed that Salmonella enterotoxin is a heat-labile protein of high molecular weight. It is suggested that enterotoxigenic and invasive properties play a vital role in the pathogenesis of Salmonella diarrhoea.

Occurrence and distribution of serotypes of the Arizona subgroup of Salmonella strains in the United States from 1967 to 1976.

The Salmonella Arizona subgroup contains gram-negative enteric bacteria that are closely related to other salmonellae biochemically, serologically, and genetically. Although the Arizona subgroup may be isolated from a wide variety of nonhuman and human sources, the arizonae are uncommonly recognized as human pathogens, and surprisingly little is known about their epidemiology. From 1967 through 1976, the Centers for Disease Control received 858 Arizona subgroup cultures from human and nonhuman sources representing 143 different serotypes in 33 somatic groups; several serotypes had not been previously reported. The 374 cultures from humans represent 71 different serotypes; extraintestinal isolates were present in 31 (44%) serotypes. Compared with data from a previous 20 years of surveillance, the proportion of Arizona subgroup strains isolated from stools, blood, and other sites was remarkably stable, but several serotypes showed marked changes in their frequency of isolation. In total, the ratio of extraintestinal to intestinal isolates was 0.37, but marked serotype-specific variation was noted, suggesting differences in virulence associated with serotype.

Meningitis por Salmonella arizonae: presentación de un caso y revisión de la literatura / Meningitis due to Salmonelle arizonae: a case and literature review

Introducción: la meningitis es una complicación rara de la infección por Salmonella. Caso clínico: lactante masculino de nueve meses de edad, no inmunocomprometido, con antecedentes de convivencia con perros, conejos, aves de corral y lagartijas. Una semana antes de su ingreso al hospital presentó diarrea que se autolimitó en 24 horas. Evoluciona con deterioro neurológico, fontanela anterior abombada, rigidez de nuca y Kerning; se cultivó Salmonella arizonae del líquido cefalorraquídeo (LCR). El manejo inicial fue con ampicilina y cloranfenicol; al conocer la sensibilidad antibiótica se continuó con cloranfenicol y cefotaxima. El LCR se negativiza después de tres días. Una tomografía computarizada mostró atrofia cerebral sin evidencia de absceso o empiema subdural. Egresa a los 31 días con hemiparesia izquierda, tono muscular aumentado y clonus, los cuales desaparecen dos meses después.Conclusiones: este es el segundo caso reportado a nivel mundial, y el primero en México, de meningitis por S. arizonae en niños.