Isolation and characterization of Listeria monocytogenes among women attending Jimma University medical center, Southwest Ethiopia

Relevance of microbiological cultures of cord blood and placental swabs in the rapid diagnosis of preterm newborn infection due to Listeria monocytogenes: A case report

Listeria monocytogenes (Lm) is a Gram-positive bacterium causing listeriosis, a rare but severe foodborne infection, particularly impactful during pregnancy. Maternal-fetal transmission can lead to adverse fetal outcomes, yet symptoms in mothers may be nonspecific, delaying intervention. Despite the severity, the mechanisms of vertical transmission remain unclear. This report describes a case of rapid Lm diagnosis in a preterm newborn using cord blood and placental swabs. A 31-week pregnant woman presented with abdominal pain, diarrhea, and reduced fetal movements after consuming raw sushi. Laboratory findings indicated infection, and she vaginally delivered a live infant with placental and fetal abscesses. Cultures confirmed Lm, with swift diagnosis aided by molecular syndromic testing. The neonate received appropriate antibiotics and was asymptomatic by the end of treatment. This case underscores the need for the rapid diagnosis of maternal-fetal listeriosis, as it poses significant risks during pregnancy, including preterm birth and neonatal complications. Current diagnostic methods often delay treatment. This report emphasizes the use of innovative molecular techniques for early diagnosis, which is crucial in managing neonatal infections, especially in preterm newborns.

Prevalence, Antimicrobial Resistance, and Characterization of Listeria Spp. Isolated from Various Sources in Ethiopia: A Comprehensive Review

Listeriosis is an important foodborne zoonotic disease affecting humans and animals in Ethiopia. This review aims to synthesize the epidemiology, prevalence, distribution, and antimicrobial resistance of Listeria species in the country. The literature reveals a widespread occurrence of Listeria infection in humans, animals, and food products, with an average prevalence of 21.6% for Listeria species and 6.9% for L. monocytogenes. Three sequence types (STs) of L. monocytogenes (2, 145, and 18) and twelve STs of L. innocua (1489, 1619, 603, 537, 1010, 3186, 492, 3007, 1087, 474, 1008, and 637) were reported from milk and dairy products. Contamination rates ranged from 4.1% to 42.9% across livestock, dairy, slaughterhouses, and processing facilities, indicating faults in production practices. Sporadic human listeriosis outbreaks have occurred since 1967, causing meningitis, perinatal infections, and deaths, with recent studies showing L. monocytogenes isolation in up to 10.4% of febrile patients, confirming foodborne transmission. Non-pathogenic Listeria species were also common on farms and in facilities. Ovine listeriosis poses a threat to Ethiopia's sheep and goat industries, with over 40% seroprevalence in some herds. Comprehensive control measures across the food chain are needed to curb contamination and protect public health. Isolates from various foods show antibiotic resistance to first-line agents but susceptibility to others like gentamicin and cephalosporins. In conclusion, this review synthesizes evidence on Listeria distribution in Ethiopia's food system and disease burden, highlighting the need for improved food safety policies and awareness.

A review of the literature of Listeria monocytogenes in Africa highlights breast milk as an overlooked human source

According to the latest WHO estimates (2015) of the global burden of foodborne diseases, Listeria monocytogenes is responsible for one of the most serious foodborne infections and commonly results in severe clinical outcomes. The 2013 French MONALISA prospective cohort identified that women born in Africa has a 3-fold increase in the risk of maternal neonatal listeriosis. One of the largest L. monocytogenes outbreaks occurred in South Africa in 2017-2018 with over 1,000 cases. Moreover, recent findings identified L. monocytogenes in human breast milk in Mali and Senegal with its relative abundance positively correlated with severe acute malnutrition. These observations suggest that the carriage of L. monocytogenes in Africa should be further explored, starting with the existing literature. For that purpose, we searched the peer-reviewed and grey literature published dating back to 1926 to date using six databases. Ultimately, 225 articles were included in this review. We highlighted that L. monocytogenes is detected in various sample types including environmental samples, food samples as well as animal and human samples. These studies were mostly conducted in five east African countries, four west African countries, four north African countries, and two Southern African countries. Moreover, only ≈ 0.2% of the Listeria monocytogenes genomes available on NCBI were obtained from African samples, contracted with its detection. The pangenome resulting from the African Listeria monocytogenes samples revealed three clusters including two from South-African strains as well as one consisting of the strains isolated from breast milk in Mali and Senegal and, a vaginal post-miscarriage sample. This suggests there was a clonal complex circulating in Mali and Senegal. As this clone has not been associated to infections, further studies should be conducted to confirm its circulation in the region and explore its association with foodborne infections. Moreover, it is apparent that more resources should be allocated to the detection of L. monocytogenes as only 15/54 countries have reported its detection in the literature. It seems paramount to map the presence and carriage of L. monocytogenes in all African countries to prevent listeriosis outbreaks and the related miscarriages and confirm its association with severe acute malnutrition.

Prevalence of Listeria monocytogenes infection in women with spontaneous abortion, normal delivery, fertile and infertile

BACKGROUND

Listeria monocytogenes with a vast range of natural reservoirs is more known for being a food-borne pathogen. Human infections have shown an impact on pregnancy outcomes, so, this study surveyed the frequency of L. monocytogenes infection involving different groups of women.

METHODS

This study enrolled a total sample consisting of 109 women with spontaneous abortion, 109 women with normal delivery, 100 fertile women, and 99 infertile women aged 19-40 years and willing to participate in the study. The research tool in this study was a questionnaire and Polymerase chain reaction (PCR) test.

RESULTS

According to the results, the frequency of L. monocytogenes infection was 4/109 (3.66%) observed among women with spontaneous abortion, 2/109 (1.83%) among women with normal delivery, 3/100 (3%) among fertile women, and 0/99 (0%) among infertile women.

CONCLUSION

There was no significant relationship between Listeria monocytogenes infection and pregnancy outcomes of spontaneous abortion and infertility.

A vigilant observation to pregnancy associated listeriosis in Africa: Systematic review and meta-analysis

The burden of human listeriosis, an emerging food-borne illness would be higher in Africa due to poor food processing practices. The severity of the disease and the high case fatality rate make human listeriosis an important public health problem. Besides, pregnant women and their fetuses are at higher risk of gaining human listeriosis. Thus, we planned to estimate the pooled prevalence of pregnancy-associated human listeriosis in Africa. Primary studies were exhaustively searched using PubMed, Cochrane, Web of Science, Google Scholar, and University of Gondar online research repository. Observational studies (cross-sectional) revealing the pregnancy-associated human listeriosis were incorporated. Eligible studies were selected and critically appraised for quality using the Joanna Briggs Institute (JBI) quality appraisal checklist. The required data were extracted and exported to Stata version 14 for meta-analysis. The pooled prevalence of pregnancy-associated human listeriosis in Africa was estimated using a weighted inverse random effect model. Sensitivity and sub-group analysis were conducted for evidence of heterogeneity. Among 639 reviewed articles, 5 articles were eligible with total study participants of 621. The pooled prevalence of pregnancy-associated listeriosis was found to be 5.17% (95% CI, 1.51, 8.82). The pooled level resistance of isolates was high. Cotrimoxazole and erythromycin were the relative choices of antibiotics for pregnancy-associated listeriosis in Africa. The burden of pregnancy-associated listeriosis in Africa was higher with an increased level of antibiotic resistance. Therefore, we recommend due attention to the deadly emerging disease in terms of health educations and the role of food hygiene particularly for risk groups, pregnant women. The antibiotics of choice should be after performing drug susceptibility test.