Preterm delivery and neonatal meningitis due to transplacental acquisition of non-typhoidal Salmonella serovar montevideo

Surgical Indications and Outcomes of Postmeningitis Subdural Collection in Infants: Single Tertiary Care Center Experience

BACKGROUND

 Postmeningitis subdural collection (PMSC) is a complication in infants with bacterial meningitis. Clinical and radiologic findings enable treating teams to gain more insights into diagnosing and managing PMSC. This study aims to establish the indications for surgical management of PMSC in infants based on a single pediatric tertiary care center experience.

METHODS

 We reviewed the hospital records of infants diagnosed with PMSC between January 2015 and December 2021. They were diagnosed based on clinical suspicion that was confirmed through imaging using computed tomography (CT) scanning or magnetic resonance imaging (MRI). All patients received antibiotic treatment, and surgical interventions using subdural drain placement or craniotomy were performed. The patients were followed up for outcomes and prognosis for 1 to 5 years.

RESULTS

 A total of 17 infants were included in the study. Infants younger than 4 months represented most cases of PMSC (64.7%). Initially, bacterial growth was seen in the cerebrospinal fluid (CSF) of 15 (88.2%) patients. The causative agents included Streptococcus pneumoniae (58.8%), Salmonella spp. (11.7%), Streptococcus agalactiae (5.9%), Escherichia coli (5.9%), and Micrococcus luteus (5.9%). Growth in subdural fluid revealed the presence of E. coli (5.9%) and Staphylococcus hominis (5.9%). All the patients received treatments including combinations of antibiotics regimens. Major indications predisposing patients with PMSC to surgery included persistent fever, seizures, and bulging fontanel in the presence of PMSC on CT or MRI. All the patients underwent surgical operations, including subdural drain placement (76.5%) and craniotomy (23.5%).

CONCLUSIONS

 Persistent fever, seizures, and bulging fontanel, in the presence of PMSC, were found to be the indications for surgical intervention in PMSC. Drainage of PMSC and continuation of antibiotics is a safe and effective modality for treatment in PMSC, with a reasonable outcome and acceptable rate of morbidity and mortality. Craniotomy should be reserved for those with thick pus collection, as burr hole surgery can be used to achieve the goal in the majority of patients.

Characterization of Salmonella isolated from donkeys during an abortion storm in China

In China, abortions of donkeys caused by Salmonella have dramatically stifled the growth of the donkey industry. However, pathogenicity of Salmonella linked to abortions in donkeys has not been previously described. Bacteria were isolated and identified from 45 donkeys that experienced abortions, and antibiograms were conducted. Pathogenicity, as median lethal dose (LD₅₀) in mice was then determined. Furthermore, a mouse abortion model was used to re-create the disease observed in donkeys. The pathologic changes in spleen, liver, intestine and embryo were observed by histological examination. An immunofluorescence assay was used to determine the location and distribution of Salmonella colonization in tissues. A clear link was made between S. abortus equi and abortions in donkeys. The bacterial strains isolated from these cases were either highly or moderately sensitive to the 8 antibiotics tested here. The strain of S. abortus equi isolated here was lethal to mice (LD₅₀ value is 1.88 × 10⁸ CFU), and caused abortions in pregnant mice. The 50% abortion-causing dose was 1.22 × 10⁸ CFU. Pathological and immunofluorescence data confirmed that the abortions in pregnant mice and donkeys were accompanied by similar disease processes. Therefore, a Salmonella induced abortion model in mice was developed, characterized by abortion, aberrant embryo development, and parenchymal hypoplasia. The mouse abortion model developed here is an important tool for the future characterization and testing therapeutic interventions.

Early onset neonatal bacterial meningitis in term infants: the clinical features, perinatal conditions, and in-hospital outcomes: A single center retrospective analysis

To compare clinical features and outcomes between early and late onset of neonatal bacterial meningitis (NBM).Patients were allocated in 2 groups: early onset neonatal bacterial meningitis (ENBM) and late onset neonatal bacterial meningitis (LNBM). Data analysis includes asphyxia at birth, premature rupture of membranes (PROM), amnionitis, amniotic fluid contamination, maternal age, clinical manifestations of the patients, laboratory findings, radiological results, complications related to meningitis, duration of hospitalization and therapeutic effect.There was no difference in gender, birth weight, gestational age, and incidence of asphyxia between 2 groups. The incidence of PROM, chorioamnionitis and amniotic fluid contamination, proportion of small-for-gestational-age infants, convulsions, intracranial hemorrhage, hyperbilirubinemia, and the protein level of cerebrospinal fluid in ENBM group were higher than that in LNBM group (P < .05); the proportion of fever, elevated C-reaction protein and the abnormal of platelet counts in LNBM group was higher than that in ENBM group (P < .05). There was no difference in the incidence of complications and hospitalization time between 2 groups. The rate of effective treatment in LNBM group was significantly higher than that in ENBM group (P < .05).Patients with conditions of amniotic fluid contamination, chorioamnionitis, small-for-gestational-age and PROM might be more prone to develop ENBM and ENBM had worse outcomes than LNBM.

Toll-Like Receptor 4 Signaling in the Ileum and Colon of Gnotobiotic Piglets Infected with Salmonella Typhimurium or Its Isogenic ∆rfa Mutants

Salmonella Typhimurium is a Gram-negative bacterium that causes enterocolitis in humans and pigs. Lipopolysaccharide (LPS) is a component of the outer leaflet of Gram-negative bacteria that provokes endotoxin shock. LPS can be synthesized completely or incompletely and creates S (smooth) or R (rough) chemotypes. Toll-like receptors (TLR) 2, 4, and 9 initiate an inflammatory reaction to combat bacterial infections. We associated/challenged one-week-old gnotobiotic piglets with wild-type S. Typhimurium with S chemotype or its isogenic ∆rfa mutants with R chemotype LPS. The wild-type S. Typhimurium induced TLR2 and TLR4 mRNA expression but not TLR9 mRNA expression in the ileum and colon of one-week-old gnotobiotic piglets 24 h after challenge. The TLR2 and TLR4 stimulatory effects of the S. Typhimurium ∆rfa mutants were related to the completeness of their LPS chain. The transcription of IL-12/23 p40, IFN-γ, and IL-6 in the intestine and the intestinal and plasmatic levels of IL-12/23 p40 and IL-6 but not IFN-γ were related to the activation of TLR2 and TLR4 signaling pathways. The avirulent S. Typhimurium ∆rfa mutants are potentially useful for modulation of the TLR2 and TLR4 signaling pathways to protect the immunocompromised gnotobiotic piglets against subsequent infection with the virulent S. Typhimurium.

Transcriptome, Spliceosome and Editome Expression Patterns of the Porcine Endometrium in Response to a Single Subclinical Dose of Salmonella Enteritidis Lipopolysaccharide

Endometrial infections at a young age can lead to fertility issues in adulthood. Bacterial endotoxins, such as lipopolysaccharide (LPS), can participate in long-term molecular changes even at low concentrations. Lipopolysaccharide plays a crucial role in the progression of septic shock, inflammation and auto-immune diseases. The aim of this study was to describe transcriptomic modulations in the porcine endometrium, induced in vivo by a single subclinical dose of LPS from Salmonella Enteritidis. which did not produce clinical symptoms of toxicity. The RNA-seq methodology was applied to reveal 456 differentially expressed regions, including 375 genes, four long noncoding RNAs, and 77 other unclassified transcripts. Two independent methods confirmed 118 alternatively spliced genes that participate i.a., in the formation of the MHC-I complex and the adaptive immune response. Single nucleotide variant-calling algorithms supported the identification of 3730 allele-specific expression variants and 57 canonical A-to-I RNA editing sites. The results demonstrated that the differential expression of genes involved in inflammation, immune response, angiogenesis and endometrial development may be maintained for up to 7 days after exposure to LPS. RNA editing sites and long noncoding RNAs (lncRNAs) play an important role in transcriptional regulatory machinery in the porcine endometrium in response to LPS administration.

Intrauterine infection caused by nontyphoidal Salmonella: a literature review

Objectives: Although nontyphoidal Salmonella infections have a prevalence of 0.2-1.8%. It is mostly described in veterinary medicine; it could be responsible for severe intra-amniotic infections in humans. The objective of this review is to describe the clinical and microbiological aspects of intrauterine infection (IUI) caused by nontyphoidal Salmonella.Methods: We reported a case analysis and subsequently conducted a systematic literature review of IUI caused by nontyphoidal Salmonella between 1966 and 2018.Results: In literature nine cases have been reported, and were confirmed by the identification of a nontyphoidal Salmonella in the biological samples. Our review reveals severe clinical presentations in pregnant women. Indeed, sepsis, spontaneous abortions, and fatal outcomes for fetuses were described in 90, 60, and 80% of the cases, respectively. The major clinical symptoms were in majority acute, with high fever, abdominal pain, metrorrhagia, and premature membranes ruptures. Nulliparity is a risk factor and the prognosis depends on the pregnancy stage. All mothers received antibiotics and their outcomes were favorable.Conclusions: Nontyphoidal Salmonella infections can be responsible for severe pregnancy complications. Considering the severe neonatal prognosis, in case of a history of diarrhea and/or sepsis, a search for this pathogen should be considered, and a preventive strategy could be discussed during pregnancy.

Analysis of the capacity of Salmonella enterica Typhimurium to infect the human Placenta

INTRODUCTION

Salmonella species are gram-negative facultative intracellular bacteria that are common causes of foodborne illness in North America. Infections by Salmonella during pregnancy are a significant cause of fetal loss in domestic livestock, and fetal and maternal mortality in mice. Furthermore, Salmonella infection is associated with miscarriage, stillbirth and preterm birth in pregnant women. Despite these collective associations, the extent to which Salmonella can infect the human placenta has not been investigated.

METHODS

Human placental villous explants from several gestational ages were exposed to Salmonella enterica serovar Typhimurium (STm) ex vivo. Infection was assessed by colony forming unit assay and whole mount immunofluorescence (WMIF).

RESULTS

Viable bacteria were recovered from placental villous explants of all gestational ages tested, but the bacterial burden was highest in 1st trimester explants. Bacterial numbers did not change appreciably with time post-infection in explants from any gestational age examined, suggesting that STm does not proliferate in placental villi. Exposure of villous explants to STm strains defective for the type III secretion systems revealed that Salmonella pathogenicity island 1 is essential for optimal invasion. In contrast to placental explants, STm infected and proliferated within villous cytotrophoblast cells isolated from term placentas. WMIF demonstrated that STm was restricted primarily to the syncytiotrophoblast layer in infected placentas.

DISCUSSION

Our study demonstrates that STm can invade into the syncytiotrophoblast but does not subsequently proliferate. Thus, the syncytiotrophoblast may function as a barrier to STm infection of the fetus.

Effect of Diarrheal Illness During Pregnancy on Adverse Birth Outcomes in Nepal

Background

Adverse birth outcomes, including low birthweight, small for gestational age (SGA), and preterm birth, contribute to 60%–80% of infant mortality worldwide. Little published data exist on the association between diarrhea during pregnancy and adverse birth outcomes.

Methods

Data were used from 2 community-based, prospective randomized trials of maternal influenza immunization during pregnancy conducted in rural Nepal from 2011 to 2014. Diarrheal illnesses were identified through longitudinal household-based weekly symptom surveillance. Diarrhea episodes were defined as at least 3 watery bowel movements per day for 1 or more days with 7 diarrhea-free days between episodes. The Poisson and log-binomial regression were performed to evaluate baseline characteristics and association between diarrhea during pregnancy and adverse birth outcomes.

Results

A total of 527 of 3693 women in the study (14.3%) experienced diarrhea during pregnancy. Women with diarrhea had a median of 1 episode of diarrhea (interquartile range [IQR], 1–2 episodes) and 2 cumulative days of diarrhea (IQR, 1–3 days). Of women with diarrhea, 85 (16.1%) sought medical care. In crude and adjusted analyses, women with diarrhea during pregnancy were more likely to have SGA infants (42.6% vs 36.8%; adjusted risk ratio = 1.20; 95% confidence interval, 1.06–1.36; P = .005). Birthweight and preterm birth incidence did not substantially differ between women with diarrhea during pregnancy and those without.

Conclusions

Diarrheal illness during pregnancy was associated with a higher risk of SGA infants in this rural South Asian population. Interventions to reduce the burden of diarrheal illness during pregnancy may have an impact on SGA births in resource-limited settings.

Unusual meningitis caused by non-typhoid Salmonella in an Italian infant: a case report

BACKGROUND

Non-typhoid Salmonella (NTS) is an important cause of bacterial meningitis in newborn and infants in developing countries, but rarely in industrialized ones. We describe an unusual presentation of bacterial meningitis in an infant, focusing on his diagnostic and therapeutic management.

CASE REPORT

An Italian two-month old male presented high fever and diarrhea with blood, associated with irritability. Inflammatory markers were high, cerebrospinal fluid analysis was compatible with bacterial meningitides but microbiological investigations were negative. Salmonella enteritidis was isolated from blood. Cerebral ultrasound and MRI showed periencephalic collection of purulent material. Specific antibiotic therapy with cefotaxime was initiated with improvement of clinical conditions and blood tests. Brain MRI follow up improved progressively.

CONCLUSIONS

Most of pediatric patients with NTS infection develop self-limited gastroenteritis, but in 3-8% of the cases complications such as bacteremia and meningitis may occur, especially in weak patients. Cerebral imaging can be useful to identify neurological findings. Although there is no standardized treatment for this condition, specific antibiotic therapy for at least four weeks is recommended. Neuroimaging follow up is required due to high risk of relapse.

Nontypical Salmonella meningitis in an infant

A previously healthy 3-month-old girl was admitted to the hospital after 1 day of fever, decreased oral intake, irritability, lethargy, and decreased activity. Examination disclosed a bulging anterior fontanelle, tachycardia (heart rate of 160 beats/minute), and urate crystals in her diaper. Lumbar puncture revealed meningitis. She was treated with broad-spectrum antibiotics and fluids. A urine culture was negative, but blood and cerebrospinal fluid cultures came back positive for Salmonella species, nontyphoid. During her hospitalization, she developed seizures but quickly improved with treatment and made a complete recovery with no sequela. Additional inquiry disclosed that the baby spent several days a week at her grandparents' house, where they raised chickens and ate fresh chicken eggs, which are well-known carriers for Salmonella.

Serovars and antimicrobial resistance of non-typhoidal Salmonella isolated from non-diarrhoeic dogs in Grenada, West Indies

Non-typhoidal salmonellosis remains an important public health problem worldwide. Dogs may harbour Salmonella in their intestines and can easily shed Salmonella in the environment with the possibility of transmission to humans. Thus, monitoring is essential to understand the role of dogs in zoonotic transmission. The objectives of this study were to determine the shedding of Salmonella by owned, apparently healthy dogs in Grenada, West Indies, to identify the serovars, and to examine their antimicrobial susceptibility profiles. Faecal samples collected during August to October, 2016 from 144 non-diarrhoeic owned dogs were examined by enrichment and selective culture for the presence of Salmonella spp. Eight (5.6%) of the tested animals were culture positive, yielding 35 Salmonella isolates that belonged to six serovars of Salmonella enterica subspecies enterica. These were serovars Arechavaleta from two dogs, Arechavaleta and Montevideo from one dog, and Javiana, Rubislaw, Braenderup and Kiambu from one dog each. All these serovars have been reported as causes of human salmonellosis globally. Antimicrobial susceptibility tests on 35 isolates showed absence of resistance to the currently used drugs for cases of human salmonellosis, including ciprofloxacin and cefotaxime. One isolate (2.9%) was resistant to neomycin, two isolates (5.7%) showed intermediate susceptibility to neomycin, and another (2.9%) had intermediate susceptibility to tetracycline. This is the first report of isolation and antimicrobial susceptibilities of non-typhoidal Salmonella serovars from dogs in Grenada. This study shows that dogs in Grenada may be involved in the epidemiology of salmonellosis.