A comprehensive review of disseminated Salmonella arizona infection with an illustrative case presentation

An evaluation of the species and subspecies of the genus Salmonella with whole genome sequence data: Proposal of type strains and epithets for novel S. enterica subspecies VII, VIII, IX, X and XI

Species and subspecies within the Salmonella genus have been defined for public health purposes by biochemical properties; however, reference laboratories have increasingly adopted sequence-based, and especially whole genome sequence (WGS), methods for surveillance and routine identification. This leads to potential disparities in subspecies definitions, routine typing, and the ability to detect novel subspecies. A large-scale analysis of WGS data from the routine sequencing of clinical isolates was employed to define and characterise Salmonella subspecies population structure, demonstrating that the Salmonella species and subspecies were genetically distinct, including those previously identified through phylogenetic approaches, namely: S. enterica subspecies londinensis (VII), subspecies brasiliensis (VIII), subspecies hibernicus (IX) and subspecies essexiensis (X). The analysis also identified an additional novel subspecies, reptilium (XI). Further, these analyses indicated that S. enterica subspecies arizonae (IIIa) isolates were divergent from the other S. enterica subspecies, which clustered together and, on the basis of ANI analysis, subspecies IIIa was sufficiently distinct to be classified as a separate species, S. arizonae. Multiple phylogenetic and statistical approaches generated congruent results, suggesting that the proposed species and subspecies structure was sufficiently biologically robust for routine application. Biochemical analyses demonstrated that not all subspecies were distinguishable by these means and that biochemical approaches did not capture the genomic diversity of the genus. We recommend the adoption of standardised genomic definitions of species and subspecies and a genome sequence-based approach to routine typing for the identification and definition of novel subspecies.

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A large-scale analysis of genomic data demonstrate Salmonella species and subspecies are genetically distinct.

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Biochemical analysis does not capture the genomic diversity of the Salmonella genus but routine species and subspecies identification can be achieved with rMLST

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Average Nucleotide Identify (ANI) with a 95% criteria was suitable to distinguish species and 98% to distinguish subspecies.

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Five novel S. enteric subspecies (VII-XI) type strains are defined.

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Reclassification of S. arizonae as a separate species is recommended.

Salmonella typhimurium myopericarditis: A case report and review of literature

BACKGROUND

Non-typhoidal salmonella (NTS) is a rare, but well-established cause of myopericarditis. Presenting symptoms may be varied, however often revolve around the dual presentation of both myopericarditis and infectious diarrhoea. Given the rarity of NTS related myopericarditis, we conducted a systematic review of the literature, identifying 41 previously reported cases.

CASE SUMMARY

We present the case of an otherwise healthy 39-year old male, presenting with chest pain in the setting of documented Salmonella typhimurium infection. After further investigation with echocardiogram and laboratory blood tests, a diagnosis of NTS associated myopericarditis was made, and the patient received antibiotic treatment with an excellent clinical outcome. Overall, myopericarditis is rare in NTS. Although treatment for myopericarditis has not been well established, there are guidelines for the treatment of NTS infection. In our review, we found that the majority of NTS cases has been pericarditis (27/42, 64.3%), with an average age of 48.3 years, and 71.4% being male. The average mortality across all cases was 31%.

CONCLUSION

Myopericarditis is a rare, but potentially serious complication of NTS infection, associated with an increased morbidity and mortality.

"Message from a turtle": otitis with Salmonella arizonae in children: Case report

RATIONALE

Salmonella enterica subsp arizonae is a common gut inhabitant of reptiles (snakes are the most common reservoir, but it also occurs in turtles). Alhough human cases owing to this organism are exceedingly rare, it may occasionally infect young infants and immunocompromised individuals with a history of intimate associations with reptiles. Our case is the 20th one among the infections with S arizonae in children, but the 2nd one of otitis and the first of mastoiditis. The other cases had different anatomical locations, such as gastroenteritis, osteomyelitis, meningitis, ankle infection, wound infection, and sinusitis.

PATIENT CONCERNS AND DIAGNOSIS

We report a rare case of otitis with Salmonella in a previously healthy adolescent, which was most likely acquired after bathing in a lake. The ear infection was complicated with mastoiditis. Audiometric testing showed a moderately conductive hearing loss (60 dB on pure-tone average).

INTERVENTION

Standard therapy for S arizonae was initiated. The surgery revealed a "hidden" cholesteatoma. Surgical management comprised of canal wall up mastoidectomy with attico-antrotomy and posterior tympanotomy followed by tympanoplasty.

OUTCOMES

Daily postoperative dressing care of the incision, along with antibiotic lavage of the external auditory canal packing, ensured a favorable evolution. The functional gain was important; the 1-month postsurgical pure tone audiogram indicated nearly normal hearing (a mean of 25 dB for air conduction thresholds).

LESSON

Salmonella enterica serotype arizonae is a rare cause of human infection, being a common organism in reptiles, like snakes and turtles. Young children are at a particular risk for acquiring such infections. Our study might encourage further epidemiologic investigations into these infections to generate a more effective strategy among public health agencies.

Pyelonephritis in Japan caused by Salmonella enterica subspecies arizonae

Salmonella enterica subsp. arizonae is a bacteria commonly found in the gut of reptiles. In humans, infections caused by this organism are rare. Most cases originate from southwestern United States, where rattlesnake products are often used in traditional medicine. In Asia, only a few cases have been described. This case report documents a case involving a 64-year-old woman with pyelonephritis caused by S. arizonae in Japan. She had no history of contact with reptiles or foreign travel. The likely route of transmission is unclear. She was treated with cephalosporins for 14 days and the pyelonephritis appeared to be resolved; however recurrence occurred twice -after two weeks and then after one month. Prolonged antibiotic therapy with amoxicillin resolved the infection. This case demonstrates that pyelonephritis associated with S. arizonae can be found outside of the typical geographic region and may not be associated with typical animal hosts.

Purulent Pericarditis with Salmonella enterica Subspecies arizona in a Patient with Type 2 Diabetes Mellitus

Purulent pericarditis is a life-threatening disorder, even in the modern antibiotic era. Although diabetes mellitus is known to be associated with an increased risk of multiple types of infections, purulent pericarditis is extremely rare. We herein report an unusual case of pericarditis caused by Salmonella enterica subspecies arizona that was not associated with any evident underlying immunosuppressive disorder apart from uncontrolled type 2 diabetes mellitus. Because a pet snake was suspected as being the source of infection in the present case, patient education and a detailed review of exposure history could play an important role in treating patients with diabetes mellitus.

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.

Fever of unknown origin in a patient initially presenting with traveller's diarrhoea

A 17-year-old male presented with diarrhoea and malaise following his return from Kenya and Tunisia. He was managed as a case of traveller's diarrhoea. Stool cultures were negative for pathogenic bacterial growth. Two weeks later he presented with worsening lower back pain. MRI of lumbosacral spine suggested L1 osteomyelitis. CT-guided spinal aspirate grew no organisms and repeat viral serology and blood cultures (including tuberculosis screening) were negative. He was treated with a 6-week course of ceftriaxone. Back pain did not improve and a repeat MRI scan 8 weeks after his antibiotic course indicated progressive changes in L1 extending to L2 with an intradiscal abscess. Repeat CT-guided spinal aspirate grew Salmonella arizonae sensitive to cotrimoxazole and ceftriaxone. He was treated with intravenous ceftriaxone and cotrimoxazole for 12 weeks. A 4-month follow-up MRI scan showed progressive improvement of the L1/L2 discitis with resolution of intradiscal fluid.

Investigating the prevalence of Salmonella in dogs within the Midlands region of the United Kingdom

Background

The intimate relationship between dogs and their owners has the potential to increase the risk of human exposure to bacterial pathogens. Over the past 40 years, there have been several reports on transmission of salmonellae from dogs to humans. This study therefore aimed to determine the prevalence of Salmonella in the faeces of dogs from the Midlands region of the United Kingdom to assess exposure risk and potential for zoonotic transmission.

Results

A total of 436 apparently healthy dogs without diarrhoea from households (n = 126), rescue centres (n = 96), boarding kennels (n = 43), retired greyhound kennels (n = 39) and a pet nutrition facility (n = 132) were investigated for Salmonella shedding. Faecal samples were processed by an enrichment culture based method. The faeces from one dog (0.23 %; 95 % confidence limit 0.006 %, 1.27 %) was positive for Salmonella. The species was S. enterica subspecies arizonae.

Conclusion

This study showed that the prevalence of Salmonella from faeces from apparently healthy dogs from a variety of housing conditions is low; however, Salmonella shedding was still identified.

Nontyphoidal cardiac salmonellosis: two case reports and a review of the literature

Nontyphoidal Salmonella, especially Salmonella enterica, is a rare cause of endocarditis and pericarditis that carries a high mortality rate. Proposed predisposing conditions include immunodeficiency states, congenital heart defects, and cardiac valve diseases. We present 2 cases of cardiovascular salmonellosis. The first case is that of a 73-year-old woman with mechanical mitral and bioprosthetic aortic valves who died from sequelae of nontyphoidal Salmonella mitral valve vegetation, aortic valve abscess, and sepsis. The second case is that of a 62-year-old man with a recent systemic lupus erythematosus exacerbation treated with oral steroids, who presented with obstructive features of tamponade and sepsis secondary to a large S. enteritidis purulent pericardial cyst. He recovered after emergent pericardial drainage and antibiotic therapy. Identifying patients at risk of cardiovascular salmonellosis is important for early diagnosis and treatment to minimize sequelae and death. We reviewed the literature to identify the predisposing risk factors of nontyphoidal Salmonella cardiac infection.

Pork meat as a potential source of Salmonella enterica subsp. arizonae infection in humans

Salmonella enterica subsp. arizonae was isolated from 13 of 123 slaughtered pigs in central Greece. The samples cultured were feces, ileum tissue, mesenteric lymph nodes, and gallbladder swabs. A total of 74 isolates from 492 samples were identified as Salmonella spp. by use of standard laboratory culture media and two commercial micromethods and by use of a polyvalent slide agglutination test for the detection of O and H antigens. Among them were 19 (25.68%) suspected to be S. enterica subsp. arizonae according to analysis with standard laboratory culture media. Of those, 14 were identified as S. enterica subsp. arizonae by the API 20E (bioMérieux, France) and the Microgen GnA+B-ID (Microgen Bioproducts, Ltd., United Kingdom) identification systems. All the isolates were tested for resistance to 23 antimicrobials. Strains identified as S. enterica subsp. arizonae were resistant to 17 (70.8%) antibiotics. The highest proportions of resistance were observed for sulfamethoxazole-trimethoprim (71.4%), tetracycline (71.4%), ampicillin (64.3%), and amoxicillin (57.1%). Two isolates were resistant to aztreonam (7.1%) and tigecycline (7.1%), used only for the treatment of humans. Thus, pork meat may play a role in the transmission of antibiotic-resistant S. enterica subsp. arizonae to human consumers. This is the first report of S. enterica subsp. arizonae isolation from pigs.

Wegener's granulomatosis mimicking inflammatory bowel disease and presenting with chronic enteritis

Wegener’s granulomatosis, also known as anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, is a small vessel vasculitis with primarily pulmonary, renal, and sinus disease manifestations. The prevalence of Wegener’s granulomatosis is three cases per 100,000 patients. Cardiovascular, neurologic, cutaneous, and joint manifestations have been reported in many case reports and case series. Gastrointestinal manifestations are less noted in Wegener’s granulomatosis, although they have been previously reported in the form of intestinal perforation and intestinal ischemia. Additionally, there are characteristic findings of vasculitis that are noted with active Wegener’s granulomatosis of the small bowel. We report a case of an elderly patient who presented with weight loss, diarrhea, and hematochezia. His symptoms were chronic and had lasted for more than 1 year before diagnosis. Inflammatory bowel disease or chronic enteritis due to Salmonella arizonae because of reptile exposure originally were suspected as etiologies of his presentation. The findings of proteinuria, renal failure, and pauci-immune glomerulonephritis on renal biopsy, in conjunction with an elevated c-ANCA titer, confirmed the diagnosis of Wegener’s granulomatosis with associated intestinal vasculitis. This case demonstrates an atypical presentation of chronic duodenitis and jejunitis secondary to Wegener’s granulomatosis, which mimicked inflammatory bowel disease.

Characterization of Salmonella occurring at high prevalence in a population of the land iguana Conolophus subcristatus in Galápagos Islands, Ecuador

The aim of the study was to elucidate the association between the zoonotic pathogen Salmonella and a population of land iguana, Colonophus subcristatus, endemic to Galápagos Islands in Ecuador. We assessed the presence of Salmonella subspecies and serovars and estimated the prevalence of the pathogen in that population. Additionally, we investigated the genetic relatedness among isolates and serovars utilising pulsed field gel electrophoresis (PFGE) on XbaI-digested DNA and determined the antimicrobial susceptibility to a panel of antimicrobials. The study was carried out by sampling cloacal swabs from animals (n = 63) in their natural environment on in the island of Santa Cruz. A high prevalence (62/63, 98.4%) was observed with heterogeneity of Salmonella subspecies and serovars, all known to be associated with reptiles and with reptile-associated salomonellosis in humans. Serotyping revealed 14 different serovars among four Salmonella enterica subspecies: S. enterica subsp. enterica (n = 48), S. enterica subsp. salamae (n = 2), S. enterica subsp. diarizonae (n = 1), and S. enterica subsp. houtenae (n = 7). Four serovars were predominant: S. Poona (n = 18), S. Pomona (n = 10), S. Abaetetuba (n = 8), and S.Newport (n = 5). The S. Poona isolates revealed nine unique XbaI PFGE patterns, with 15 isolates showing a similarity of 70%. Nine S. Pomona isolates had a similarity of 84%. One main cluster with seven (88%) indistinguishable isolates of S. Abaetetuba was observed. All the Salmonella isolates were pan-susceptible to antimicrobials representative of the most relevant therapeutic classes. The high prevalence and absence of clinical signs suggest a natural interaction of the different Salmonella serovars with the host species. The interaction may have been established before any possible exposure of the iguanas and the biocenosis to direct or indirect environmental factors influenced by the use of antimicrobials in agriculture, in human medicine or in veterinary medicine.

Salmonella enterica ssp. arizonae infection in a 43-year-old Italian man with hypoglobulinemia: a case report and review of the literature

Introduction

Salmonella enterica ssp. arizonae is an uncommon human pathogen with serious infections reported in immunocompromised hosts. In Europe, only a few cases have been described. Patients with this infection usually have a history of contact with reptiles or travel abroad. We present a case report of infection in a patient with hypoglobulinemia and a literature review.

Case presentation

We describe the case of a 43-year-old Caucasian Italian man with hypoglobulinemia who presented to our hospital with sepsis and diarrhea. A stool culture yielded S. enterica ssp. arizonae. Our patient was treated with oral ciprofloxacin and made a full recovery. We also present a review of the cases of S. enterica ssp. arizonae infections previously reported in Europe.

Conclusions

The majority of infections from S. enterica ssp. arizonae occur in patients who are immunocompromised. Data from the literature suggests that it may be difficult to eradicate the bacteria and thus, prolonged antibiotic courses are often used. It would be advisable for clinicians to investigate for pre-existing immune dysfunction if S. enterica ssp. arizonae is isolated. In Italy, although there have only been a few cases, the likely route of transmission remains unclear and requires further surveillance.

Osteomyelitis due to Salmonella enterica subsp. arizonae: the price of exotic pets

We describe a 31-year-old immunocompromised patient who developed sepsis and osteomyelitis due to Salmonella enterica subsp. arizonae secondary to exposure to iguana and snakes kept as pets at her home, and review all 23 previously published cases of bone and joint infections due to this organism, for a total of nine children and 15 adults. Eleven of the adults were female (73%), compared with three (33%) of the children (p <0.01). Significant underlying illnesses were present in all 15 adults and in five children (55%, p <0.05); 10 (77%) of the adults were immunosuppressed, compared with one child only (17%) (p <0.05). In ten of the adults the knee was infected (67%), compared with one child only (11%, p <0.01). Antibiotic therapy was prolonged in both adults and children, and in most cases consisted of 4-6 weeks of parenteral treatment. Complete cure and survival was attained in 11 of 15 adults (73%) and all nine children (NS). Optimal antibiotic treatment probably consists of ceftriaxone or a fluoroquinolone, if the organism is susceptible.

Respiratory infections unique to Asia

Asia is a highly heterogeneous region with vastly different cultures, social constitutions and populations affected by a wide spectrum of respiratory diseases caused by tropical pathogens. Asian patients with community‐acquired pneumonia differ from their Western counterparts in microbiological aetiology, in particular the prominence of Gram‐negative organisms, Mycobacterium tuberculosis, Burkholderia pseudomallei and Staphylococcus aureus. In addition, the differences in socioeconomic and health‐care infrastructures limit the usefulness of Western management guidelines for pneumonia in Asia. The importance of emerging infectious diseases such as severe acute respiratory syndrome and avian influenza infection remain as close concerns for practising respirologists in Asia. Specific infections such as melioidosis, dengue haemorrhagic fever, scrub typhus, leptospirosis, salmonellosis, penicilliosis marneffei, malaria, amoebiasis, paragonimiasis, strongyloidiasis, gnathostomiasis, trinchinellosis, schistosomiasis and echinococcosis occur commonly in Asia and manifest with a prominent respiratory component. Pulmonary eosinophilia, endemic in parts of Asia, could occur with a wide range of tropical infections. Tropical eosinophilia is believed to be a hyper‐sensitivity reaction to degenerating microfilariae trapped in the lungs.

This article attempts to address the key respiratory issues in these respiratory infections unique to Asia and highlight the important diagnostic and management issues faced by practising respirologists.

Clonal relatedness of Salmonella isolates associated with invasive infections in captive and wild-caught rattlesnakes

This study examines the serotype distribution and clonal relatedness among Salmonella isolates obtained from healthy and diseased snakes. Isolates from extraintestinal body sites were obtained through routine diagnostic lab submissions from snakes in two facilities that had experienced a high prevalence of osteomyelitis in Crotalus species. Gastrointestinal isolates were predominantly from fecal samples collected from healthy snakes of both crotalid and non-crotalid species in one facility. PFGE macrorestriction analysis of Salmonella isolates confirmed the clonal and species-restricted nature of Salmonella serotype IIIa 56: z4, z23: - in one facility. Fourteen of 15 isolates from suspected osteomyelitis lesions in wild-caught snakes at the second facility were also from Salmonella subgroup IIIa (serotype IIIa 18: z4, z23: -) and appeared to be closely related by PFGE. Evaluation of a PCR assay for the spvC gene in 209 isolates demonstrated that this method consistently distinguished isolates of subgroup IIIa from those of subgroup IIIb. The data presented establish that Salmonella of subgroup IIIb are abundant and regularly associated with gastrointestinal shedding in snakes but that Salmonella in subgroup IIIa disproportionately cause infections in bone or other extraintestinal sites.

A Bayesian approach to acute infectious diarrhea in adults

Acute infectious diarrhea is a yearly occurrence for most Americans, and is associated with 1 million hospitalizations and about 6000 deaths in the United States annually. Up to 80% of acute infectious diarrhea is caused by noroviruses, which produce a clinically mild illness with a predictable short course and good outcome that make laboratory testing and antimicrobial treatment unnecessary. Most diarrhea-causing bacteria and protozoa can cause a clinical illness "like norovirus"; when they do so in healthy adults neither specialized testing nor antimicrobials is required. The presence or absence of epidemiologic evidence (such as travel, hospitalization, antibiotic use, other exposures)and clinical evidence (such as diarrhea frequency and duration, severity of abdominal pain and fever, character of stool, presence of chronic illness or immune deficiency) can change the probability of "not norovirus" from as low as 8% to as high as 100%. Such probabilities guide the use of laboratory testing and antimicrobial therapy in patients who have acute infectious diarrhea.