Salmonella meningitis: report of three cases in adults and literature review

Infant Salmonella enterica Meningitis: A Rare Case Report and Review of Literature

Meningitis caused by Salmonella enterica can be a fatal condition that is more common in low- and middle-income countries and uncommon in infants. This case of a 2-month-old male infant reported Salmonella meningitis symptoms, such as fever, irritability, altered sensorium, and diarrhoea. Clinical examination revealed bulging anterior fontanelles, dehydration, and sunken eyes. Screening for normal hearing, cranial ultrasound, and magnetic resonance imaging (MRI) revealed no brain abnormalities. A cerebrospinal fluid (CSF) culture revealed gram-negative Salmonella enterica bacilli. Treatment with meropenem and ampicillin was initiated after antibiotic susceptibility testing showed sensitivity. The patient's cerebrospinal fluid parameters and bacterial growth improved after antibiotic therapy. Two weeks later, the baby was neurologically healthy and discharged. Paediatricians should be aware that Salmonella enterica can cause meningitis in children with non-specific symptoms.

A rare case of extensively drug-resistant Salmonella typhi meningitis in a 9-year old: a case report

Meningitis caused by Salmonella typhi is rare and is generally seen in infants. We report a case of a 9-year-old boy with extensively drug-resistant S. typhi meningitis. The patient was diagnosed using a culture sensitivity test and successfully treated with meropenem. Culture sensitivity may be included in routine testing for the diagnosis of S. typhi especially in developing countries due to high burden of disease and emergence of drug resistance.

Activation of Toll-like receptor 5 in microglia modulates their function and triggers neuronal injury

Microglia are the primary immune-competent cells of the central nervous system (CNS) and sense both pathogen- and host-derived factors through several receptor systems including the Toll-like receptor (TLR) family. Although TLR5 has previously been implicated in different CNS disorders including neurodegenerative diseases, its mode of action in the brain remained largely unexplored. We sought to determine the expression and functional consequences of TLR5 activation in the CNS. Quantitative real-time PCR and immunocytochemical analysis revealed that microglia is the major CNS cell type that constitutively expresses TLR5. Using Tlr5^−/− mice and inhibitory TLR5 antibody we found that activation of TLR5 in microglial cells by its agonist flagellin, a principal protein component of bacterial flagella, triggers their release of distinct inflammatory molecules, regulates chemotaxis, and increases their phagocytic activity. Furthermore, while TLR5 activation does not affect tumor growth in an ex vivo GL261 glioma mouse model, it triggers microglial accumulation and neuronal apoptosis in the cerebral cortex in vivo. TLR5-mediated microglial function involves the PI3K/Akt/mammalian target of rapamycin complex 1 (mTORC1) pathway, as specific inhibitors of this signaling pathway abolish microglial activation. Taken together, our findings establish TLR5 as a modulator of microglial function and indicate its contribution to inflammatory and injurious processes in the CNS.

Salmonella typhi Meningitis in an Immunocompetent Asian Adult

Enteric salmonella infections are common in the United States though nonenteric salmonella infections in immunocompetent adults are exceedingly rare in the United States, and meningitis is one of the least common extra-intestinal sites. In addition, it is very unusual for a patient with bacterial meningitis to present with meningitis signs and symptoms of >72 h duration like aseptic meningitis. 

A 25-year-old Indian male, without any past medical history brought by friends to the ER had fever and irritability for a week. He became increasingly somnolent and confused three days back. Physical exam reveals signs of meningitis and laboratory showed cerebrospinal fluid (CSF) studies suggestive of bacterial meningitis. Culture of CSF grew Salmonella typhi and later on blood culture also grew S. typhi. The patient became worse with cerebral edema and hydrocephalous suspected by change in neurological status and confirmed by ultrasound of eye ball examining optic nerve sheath diameter and CT scan of brain. The patient required neurosurgical intervention and hence external ventricular drain was placed. The patient was also placed on mechanical ventilation. Subsequently he developed ventilator associated pneumonia (VAP) with carbapenem-resistant Pseudomonas aeruginosa. The patient underwent tracheostomy and successfully completed treatment of VAP and was transferred to his home country after four months. Thus we describe a rare case of salmonella meningitis in an immunocompetent adult.

Siblings with typhoid fever: An investigation of intrafamilial transmission, clonality, and antibiotic susceptibility

BACKGROUND

Typhoid fever usually manifests as an acute disease. However, asymptomatic carriage with Salmonella Typhi may occur. This study investigated a family setting of severe typhoid fever in Switzerland months after return from Bangladesh.

METHOD

Standard microbiological procedures were performed. Testing for S. Typhi IgM antibodies was done using a novel immunochromographic lateral flow assay. Whole genome sequencing (WGS) followed by comparative core genome multilocus sequence typing (cgMLST) was performed on the S. Typhi isolates.

RESULTS

Four months after returning from a visit to Bangladesh sibling 1 (9 months) was diagnosed with a S. Typhi meningitis and sibling 3 (8 years) was identified as asymptomatic S. Typhi carrier. Sibling 2 (2 years) was retrospectively diagnosed with typhoid fever by IgM serology at the time point of admission to the hospital. Parents were asymptomatic and culture-negative. WGS analysis of family S. Typhi isolates showed clonality and strongest homology with S. Typhi strains occurring in Bangladesh. The S. Typhi strain showed resistance against fluoroquinolones. A 4-week course of ceftriaxone resulted in full recovery of sibling 1. S. Typhi was eradicated from sibling 3 following azithromycin treatment for 14 days.

CONCLUSION

S. Typhi, acquired from a visit to Bangladesh, was most likely transmitted within the family from one brother as asymptomatic shedder to his 9-month-old brother who manifested S. Typhi meningitis as a very rare and life-threatening presentation of typhoid fever. S. Typhi infection should be considered even in case of uncommon manifestations and irrespective of the interval between disease presentation and travel to an endemic area.

Salmonella Typhi meningitis in a 9-year old boy with urinary schistosomiasis: a case report

Background

Cases of Salmonella Typhi meningitis have been rarely reported in infants. There are few documented cases of persistent salmonella bacteraemia in patients with schistosomiasis. A presented case highlights the importance of broadening the list of pathogens that can cause meningitis among older children in schistosomiasis endemic regions.

Case presentation

The reported case is of a 9-year old sukuma-black African boy referred to Bugando Medical Centre with complaints of fever, abdominal pain, headache and generalized body weakness. On examination; the child was febrile (39°C) with neck stiffness and distended abdomen. Cerebrospinal fluid culture was positive for Salmonella Typhi. In addition on urine sediments microscopy, Schistosoma haematobium eggs were seen. The child improved clinically on ceftriaxone and praziquantel, and was discharged 3 weeks after admission.

Conclusion

Complicated persistent salmonella infection should be considered in schistosomiasis endemic areas. More research should be done to confirm the association between salmonella infections and urinary schistosomiasis.

Obscure manifestations of Salmonella subdural empyema in children: case report and literature review

PURPOSE

Salmonella intracranial infections, including subdural empyema and brain abscess, are rare clinical manifestations in children. The aim of this study is to investigate the clinical course of Salmonella subdural empyema in infants and children.

METHODS

We report a 9-month-old female infant diagnosed as Salmonella subdural empyema with clinical features of prolonged fever for more than 2 months and episodic focal seizures. Literature published between 1986 and 2010 relevant to Salmonella subdural empyema in children were reviewed. The clinical presentations and laboratory findings were analyzed.

RESULTS

Seventeen cases with Salmonella subdural empyema, including our index case, has been reported with detailed clinical presentation. Fever (17/17; 100%), symptoms and signs of increased intracranial pressure (8/17; 47%), seizures (8/17; 47%), and limb paralysis (8/17; 47%) were the most frequent clinical features. Among these cases, unknown causative organism prior to surgery (11/17; 65%) and prolonged fever for more than 3 weeks (5/17; 29%) were also noticed. Sixteen out of 17 patients (94%) required surgical intervention for treatment. The morbidity rate and mortality rate were 29% (5/17) and 6% (1/17), respectively.

CONCLUSION

Subdural empyema is considered to be a disease with rapid progression. However, the cases caused by Salmonella species may present a slow disease course. Surgical intervention is sometimes the only way to detect the pathogen.

Humanized mice are susceptible to Salmonella typhi infection

Salmonella enterica serovar Typhi is a pathogen that only infects humans. Currently, there is no animal model for studying this pathogen. Recently, alymphoid RAG-2(-/-)/γ(c)(-/-) mice engrafted with human leukocytes, known as humanized mice, have been successfully utilized to develop experimental models for several human-specific viral infections, including HIV, human-like dengue fever and hepatitis C virus. Little is known about the usefulness and feasibility of the humanized mouse model for the study of human-specific bacterial pathogens, such as S. typhi. The aim of this study was to determine if Salmonella enterica serovar Typhi could establish productive infection in humanized mice. Here we report that intravenous inoculation of S. typhi into humanized mice, but not controls, established S. typhi infections. High bacterial loads were found in the liver, spleen, blood and bone marrow of mice reconstituted with human leukocytes, but not in the unreconstituted control mice. Importantly, S. typhi-infected humanized mice lost significant body weight, and some of the infected mice displayed neurological symptoms. Our data suggest, for the first time, that humanized mice are susceptible to S. typhi challenge and that this model can be utilized to study the pathogenesis of S. typhi to develop novel therapeutic strategies.

Presence of wild-type and attenuated Salmonella enterica strains in brain tissues following inoculation of mice by different routes

Salmonella enterica serovar Typhi and Typhimurium vaccine candidates elicit significant immune responses in mice by intranasal (i.n.) immunization. Because of the proximity of the cribriform plate of the ethmoid bone, we were concerned that Salmonella bacteria delivered i.n. might access the brain. Accordingly, wild-type and attenuated (by single and double mutations) strains of S. enterica serovars Typhimurium and Typhi were recovered at low numbers initially from the olfactory lobe and then from the brain for 3 to 4 days after i.n. immunization. This was independent of invA gene function. Although the presence of bacteria in blood 1 to 3 h after i.n. inoculation was sometimes observed, this was infrequent compared to the frequency of bacteria detected in brain tissues. In confirmation of recent observations by Wickham et al. (M. E. Wickham, N. F. Brown, J. Provias, B. B. Finlay, and B. K. Coombes, BMC Infect. Dis. 7:65, 2007) that oral inoculation with wild-type S. enterica serovar Typhimurium strains lead to bacteria in blood with subsequent colonization of brain tissues with neurological symptoms of disease, we found similar results by using the i.n. and intraperitoneal (i.p.) routes of inoculation for wild-type but not for attenuated strains of S. enterica serovar Typhimurium. In contrast, a highly modified attenuated S. enterica serovar Typhimurium strain was not present in brain tissues when administered at higher doses by the oral, i.n., and i.p. routes than the wild-type strain even though the presence of bacteria in blood was detectable 1 to 3 h after inoculation by each of the three routes. Our results indicate that i.n. and possibly even oral delivery of live Salmonella vaccines may be unsafe although it is possible to reduce this risk by appropriate genetic modifications.

Salmonella meningitis in an immunocompetent adult

Non-enteric salmonella infections in immunocompetent adults are exceedingly rare in the United States, and meningitis is one of the least common extra-intestinal sites. In addition, it is very unusual for a patient with bacterial meningitis to present with classic meningitis signs and symptoms of > 72 h duration. The objective of this work is to describe a rare case of salmonella meningitis in an immunocompetent adult and, in the context of previously published case reports, describe the frequently atypical clinical course of salmonella meningitis along with the potential pitfalls encountered during its evaluation and treatment. An otherwise healthy 45-year-old man presented to our Emergency Department with frontal headache, fever, and stiff neck of 7 days duration. He was alert and oriented in triage, where he was noted to be afebrile, mildly tachycardic, with a normal blood pressure and respiratory rate; shortly after triage he developed a high fever, severe tachycardia, hypotension, and a change in mental status. He was resuscitated according to our severe sepsis protocol and treated empirically for bacterial meningitis. Blood and cerebrospinal fluid cultures grew group D Salmonella berta. An evaluation for underlying immunodeficiency was unrevealing. The patient was discharged home on hospital day 7 in good condition. Salmonella meningitis can present with an indolent course and can mimic, in many misleading ways, the less serious diagnosis of aseptic meningitis. This case highlights the need for an unbiased clinical assessment, aggressive management of critical illness, and point-for-point correspondence between clinical data and assigned diagnosis.

Salmonella enteritidis meningitis in a first time diagnosed AIDS patient: case report

We describe a patient with salmonella enteritidis meningitis and unknown HIV infection.

Setting: A 14-bed adult intensive care unit in a tertiary hospital.

The patient was brought to the emergency department with fever, nuchal rigidity and confusion. A first cerebrospinal fluid examination was non diagnostic. After a short period of improvement the patient developed septic shock. A second cerebrospinal fluid specimen was purulent. Both specimens yielded salmonella enteritidis and a blood culture as well. An Eliza reaction was performed and showed positive for HIV. The CD4(+) cells count was 16/mm³. The patient died with refractory shock eight days after admission in the intensive care unit.

Oral infection of mice with Salmonella enterica serovar Typhimurium causes meningitis and infection of the brain

Background

Salmonella meningitis is a rare and serious infection of the central nervous system following acute Salmonella enterica sepsis. For this pathogen, no appropriate model has been reported in which to examine infection kinetics and natural dissemination to the brain.

Methods

Five mouse lines including C57BL/6, Balb/c, 129S6-Slc11a1tm1^Mcg, 129S1/SvImJ, B6.129-Inpp5dtm1^Rkh were used in the murine typhoid model to examine the dissemination of systemic Salmonella enterica serovar Typhimurium following oral infection.

Results

We report data on spontaneous meningitis and brain infection following oral infection of mice with Salmonella enterica serovar Typhimurium.

Conclusion

This model may provide a system in which dissemination of bacteria through the central nervous system and the influence of host and bacterial genetics can be queried.

Rare Infections Are Just an Airplane Trip Away: Salmonella Typhi Meningitis in a Recent Immigrant to the United States

We report a case of a 24-year-old immigrant from Bangladesh with Salmonella typhi meningitis, a rare disease in the United States, especially among adults. The common manifestations of meningitis such as neck rigidity and changes in mental status did not develop and Kernig sign was absent. The patient was successfully treated with intravenous ceftriaxone. This case demonstrates the importance of considering endemic infections in the country of origin when recent immigrants and returnees to the United States present with febrile illness.

Successful treatment of pulmonary mucormycosis in an allogenic bone-marrow transplant recipient with combined medical and surgical therapy

Mucormycosis is a rare, but severe, complication in allogenic bone-marrow recipients with a mortality rate of about 80%. Moreover, its incidence appears to have increased within the last decade. We report a case of pulmonary and nasal mucormycosis in a 55-y-old patient, which occurred 1 y after BMT. Treatment combining 4 months of amphotericin B, early surgical resection of infected tissue and discontinuation of immunosuppressive treatment allowed the cure of this mould infection.

Invasion of the central nervous system by intracellular bacteria

Infection of the central nervous system (CNS) is a severe and frequently fatal event during the course of many diseases caused by microbes with predominantly intracellular life cycles. Examples of these include the facultative intracellular bacteria Listeria monocytogenes, Mycobacterium tuberculosis, and Brucella and Salmonella spp. and obligate intracellular microbes of the Rickettsiaceae family and Tropheryma whipplei. Unfortunately, the mechanisms used by intracellular bacterial pathogens to enter the CNS are less well known than those used by bacterial pathogens with an extracellular life cycle. The goal of this review is to elaborate on the means by which intracellular bacterial pathogens establish infection within the CNS. This review encompasses the clinical and pathological findings that pertain to the CNS infection in humans and includes experimental data from animal models that illuminate how these microbes enter the CNS. Recent experimental data showing that L. monocytogenes can invade the CNS by more than one mechanism make it a useful model for discussing the various routes for neuroinvasion used by intracellular bacterial pathogens.

A case of retroperitoneal abscess caused by Salmonella Oranienburg

The authors report a case of retroperitoneal abscess caused by Salmonella Oranienburg in an 8-year-old girl. This was one case in an epidemic of food poisoning from Salmonella Oranienburg or Salmonella Chester transmitted by many kinds of contaminated dried squid products. This is the first reported case of a retroperitoneal abscess by Salmonella Oranienburg.