Congenital Brucellosis: A Systematic Review of the Literature

Gated nanoprobe utilizing metal-organic frameworks for identifying and distinguishing between the wild strains and the vaccine strains of brucella

In the assay for Brucella, the identification and differentiation of wild strains and vaccine strains present a significant challenge. Currently, there aren't any commercially available product to address this issue. In this study, we have developed a novel gated nanoprobe by utilizing Metal-Organic Frameworks (MOFs) as a scaffold and hairpin DNA as a "gating switch". Specifically, Probe 1 with hairpin structure (P1h) targets a gene that is present in both wild strains Y3 (B. melitensis biovar 3) and vaccine strains A19 (Brucella abortus strains A19). We successfully applied this probe to screen positive samples of Brucella without any cross-reactivity with other substances. Additionally, we identified another specific gene exclusively found in wild strains, which serves as Probe 2 with hairpin structure (P2h) to confirm the strain type. Simultaneous detachment of both P1h and P2h from the MOFs leads to the release of Rhodamine 6G (Rho 6G) and Fluorescein (Flu), specifically indicating the presence of wild strains. If only P1h detaches and the Flu signal is detected, it suggests the presence of vaccine strains. Importantly, this method offers high accuracy, with a detection rate of 90% and a recovery rate of 94.71% to 107.65%, while avoiding cross-reactions with MO and TB. This one-step experiment provides reliable identification and differentiation of Y3 and A19, addressing concerns related to long periodicity, interference from individual variations, and the complex design of primers in existing laboratory methods. Furthermore, our approach successfully detects target 1 (T1) and target 2 (T2) at concentrations ranging from 10-6 M to 10-9 M, with a detection limit of 6.7 × 10-10 M and 6.4 × 10-10 M, respectively. Importantly, our strategy is cost-effective (around $1) and offers higher detection efficiency compared to traditional laboratory methods.

Farmers' perceptions of bovine brucellosis in Benin

Background and Aim

Cattle are the main source of meat in Benin. To improve the attitudes and practices of cattle breeders in relation to bovine brucellosis, a study has been carried out in Benin according to different agroecological zones. This study aimed to assess farmers' knowledge and practices concerning bovine brucellosis to generate essential information for control programs and public health interventions.

Materials and Methods

The study was conducted from February to May 2022, during which 608 farmers were interviewed using a structured questionnaire that provided information on socioeconomic characteristics, knowledge, and practices related to bovine brucellosis. Analysis of variance, Poisson regression, and the proportion comparison test were used to compare these characteristics in the different agroecological zones. At the end of the surveys, three distinct and homogeneous groups of perceptions (hierarchical classification of Multiple Correspondence Analysis components of R software) of bovine brucellosis were identified (these groups only consider farmers who declared knowledge of the disease). Groups were formed by applying the multiple correspondence analysis function of the FactoMineR library in R software, followed by a hierarchical ascending classification using the hierarchical clustering on principal component function of the same software (Agrocampus Rennes, France).

Results

Only 38% of respondents were aware of brucellosis. Knowledge of brucellosis was not related to sex or education level but was higher among farmers in agroecological Zones 1 and 4. Ethnic Dendi herders (62.16%) had better knowledge of the disease than those from other sociolinguistic groups (Somba: 50%, Fulani: 40.91%, Baribas: 26.97%, and others: 8.82%). Reduced milk production (98.29%), presence of hygroma (87.18%), and abortion (56.84%) are the main signs reported by herders familiar with the disease. All three groups had good knowledge of the disease and its zoonotic nature. Groups 1 (96% of breeders) and 2 (2.14%) were aware of the risk factors (contact with affected animals, the consumption of raw milk, the handling of runts, and reproductive rejection). In the case of Brucella, they prefer to treat animals rather than sell them and use both traditional and modern medicines. Group 3 (1.71%) did not know the risk factors and preferred to sell animals in the event of illness.

Conclusion

Pastoralists need to be made aware of the mode of transmission of bovine brucellosis, its clinical manifestations, its impact on animal health, and the zoonotic nature of the disease (impact on public health) so that bovine brucellosis can be rapidly detected in herds.

Immune Responses Potentially Involved in the Gestational Complications of Brucella Infection

Infection by Brucella species in pregnant animals and humans is associated with an increased risk of abortion, preterm birth, and transmission of the infection to the offspring. The pathogen has a marked tropism for the placenta and the pregnant uterus and has the ability to invade and replicate within cells of the maternal-fetal unit, including trophoblasts and decidual cells. Placentitis is a common finding in infected pregnant animals. Several proinflammatory factors have been found to be increased in both the placenta of Brucella-infected animals and in trophoblasts or decidual cells infected in vitro. As normal pregnancies require an anti-inflammatory placental environment during most of the gestational period, Brucella-induced placentitis is thought to be associated with the obstetric complications of brucellosis. A few studies suggest that the blockade of proinflammatory factors may prevent abortion in these cases.

Congenital Brucellosis: A Case Report

Background: Brucellosis is the most common zoonotic infection worldwide, and is caused by bacterial genus Brucella. The disease is rarely transmitted through human-to-human transmission. Few cases have been reported about vertical transmission of human brucellosis. Herein, we reported a case of congenital brucellosis, with clear evidence of pathogen detected in mother's placental specimen. Case Presentation: A 34-day-old girl was admitted to the department of pulmonology with fever for 8 days. Three blood samples and one sample of cerebrospinal fluid were positive for Brucella melitensis. The diagnosis of brucellosis and B. melitensis meningitis were established, along with hyperbilirubinemia and liver dysfunction. Treatment of rifampicin (for 6 weeks) and meropenem (for 2 weeks) was administered. However, the disease relapsed within 18 days. Thereafter, a combination therapy of rifampicin and sulfamethoxazole/trimethiprim (SMZ/TMP) was administered for 8 weeks. The disease relapsed again in 42 days. For chronic brucellosis, three courses of combination therapy of rifampicin and SMZ/TMP was administered. The mother had fatigue and arthralgia for 2 weeks, fever and membrane rupture 1 day before the baby was born. B. melitensis DNA was detected in the mother's placental specimen by next-generation sequencing and bacterial identification under microscope proved chorioamnionitis. Conclusions: We reported a confirmed case of congenital brucellosis. This disease should be closely monitored even in nonepidemic areas. The treatment of brucellosis in infancy faces challenges of drug choice and disease relapse.

Congenital brucellosis: A case report

Although rare, brucellosis is endemic in the Kingdom of Saudi Arabia (KSA). In the case presented here, a neonate was born at 29 weeks gestation with severe respiratory depression, pyrexia; hypotension and an elevated white blood cell count. Her mother was a 19-year-old pregnant woman who developed premature rupture of the membranes and went into labour early. Sepsis was suspected and so the neonate received dobutamine and empiric ampicillin/gentamicin. The mother reported visiting a farm during her pregnancy and so congenital brucellosis was considered a possibility. Blood cultures were positive for Gram-negative coccobacilli and serology confirmed the presence of Brucella abortus and B. meltiness. Antibiotic treatment was changed to rifampin/gentamicin/ciprofloxacin but on day 17 the baby deteriorated and gentamicin was discontinued and meropenem was added. The neonate gradually improved; meropenem was discontinued on day 24 and the baby was discharged from hospital on day 38.

Human brucellosis in pregnancy - an overview

Human brucellosis during pregnancy is characterized by significantly less pronounced adverse obstetric outcomes than in animals, but with remarkably more adverse obstetric outcomes when compared to healthy pregnant women. Seroprevalence of brucellosis in pregnancy and cumulative incidence of brucellosis cases per 1000 delivered obstetrical discharges in endemic regions were reported to be 1.5–12.2% and 0.42–3.3, respectively. Depending on the region, the frequency of pregnant women in the cohorts of patients with brucellosis was from 1.5% to 16.9%. The most common and the most dramatic unfavorable outcomes during brucellosis in pregnancy are the obstetric ones, manifested as abortions (2.5–54.5%), intrauterine fetal death (0–20.6%), or preterm deliveries (1.2–28.6%), depending on the stage of pregnancy. Other unfavorable outcomes due to brucellosis are addressed to infant (congenital/neonatal brucellosis, low birth weight, development delay, or even death), the clinical course of disease in mother, and delivery team exposure. When diagnosed in pregnant women, brucellosis should be treated as soon as possible. Early administration of adequate therapy significantly reduces the frequency of adverse outcomes. Rifampicin in combination with trimethoprim-sulfamethoxazole for 6 weeks is the most commonly used and recommended regimen, although monotherapies with each of these two drugs are also widely used while waiting for the results from prospective randomized therapeutic trials. As no effective human vaccine exists, screening of pregnant women and education of all women of childbearing age about brucellosis should be compulsory preventive measures in endemic regions.

Brucellosis awareness and knowledge in communities worldwide: A systematic review and meta-analysis of 79 observational studies

BACKGROUND

Brucellosis is regarded as a major zoonotic infection worldwide. Awareness and knowledge of brucellosis among occupational workers is considered an important aspect of brucellosis control in both humans and animals. The aim of this study was to explore the distributions of the pooled awareness level and the knowledge level of the disease worldwide.

METHODS

A meta-analysis was carried out to obtain pooled brucellosis awareness levels and knowledge levels of respondents regarding the zoonotic nature of brucellosis, mode of brucellosis transmission, and brucellosis symptoms in animals and humans. The analysis was conducted and reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-analyses guidelines.

RESULTS

A total of seventy-nine original articles reporting the brucellosis awareness levels of in populations from 22 countries were assessed. The total pooled awareness level of brucellosis was 55.5%, and the pooled awareness levels regarding the zoonotic nature of brucellosis, mode of brucellosis transmission, signs of human brucellosis and signs of animal brucellosis were 37.6%, 35.9%, 41.6%, and 28.4% respectively. The pooled awareness level was higher than the brucellosis-related knowledge level. Subgroup analyses showed that no obvious differences in brucellosis awareness levels between high-risk populations in Asia and Africa. Health workers (including human health workers and veterinarians) had the greatest overall awareness and knowledge of human brucellosis. The overall awareness levels and knowledge levels of livestock owners (farmers) and herders were higher than those of dairy farmers and abattoir workers. In addition, awareness and knowledge levels were higher among people who were involved in bovine, caprine and ovine animal production or in caprine and ovine animal production than among people who were involved in only bovine animal production.

CONCLUSIONS

Insufficient awareness and knowledge of brucellosis were observed in the original studies conducted mainly in Asia and Africa. Interventions to improve public knowledge about brucellosis are urgently needed.

Congenital brucellosis in a Chinese preterm neonate: A case report

Although extremely rare, congenital brucellosis can occur via perinatal transmission. We report a case of an infant born prematurely at 34–36 weeks' gestation who had pyrexia, shortness of breath, hepatosplenomegaly and thrombocytopenia. Blood cultures were positive for Gram-negative coccobacilli and Brucella infection was suspected. While, serological tests were negative for Brucella antibodies, B. melitensis infection was confirmed by polymerase chain reaction (PCR). Serology of the parents’ blood confirmed the presence of Brucella. The family did not live in an endemic area but had ridden a camel 12 months before the pregnancy. The bacteria may have been sexually transmitted from father to mother and then to foetus via an intrauterine infection. In endemic areas or where the family has been in close contact with infected animals, brucellosis should be suspected in a severely ill neonate with an unknown infection. Thorough medical histories from the family are essential as early diagnosis and prompt therapy will almost certainly improve neonatal outcome.

Infection by Brucella melitensis or Brucella papionis modifies essential physiological functions of human trophoblasts

Brucellosis is a zoonosis caused by bacteria of the Brucella genus. In ruminants, brucellosis causes abortion, followed by chronic infection and secretion of bacteria in milk. In humans, it usually presents as flu-like symptoms, with serious complications if untreated. Epidemiological studies have only recently established that brucellosis can also cause pregnancy complications in women, but the pathogenic mechanisms are unknown. Pioneering studies in ruminants showed that Brucella infect trophoblasts and then colonise the placenta where they grow to high density. A recent study showed that the main zoonotic Brucella species can infect human cytotrophoblasts (CTB) and extravillous trophoblasts (EVT). In this work, we show that Brucella papionis (associated with stillbirth in primates) also infects human trophoblasts. However, it replicates actively in CTB, whereas its replication is very restricted within EVT. We also observed alteration of several trophoblastic functions upon infection by B. papionis or Brucella melitensis (the most prevalent species in human brucellosis). Infection altered the production of hormones, the ability of CTB to form syncytiotrophoblasts, and the invasion capacity of EVT. We also found that infection can spread between different types of trophoblasts. These findings constitute a new step in understanding how Brucella infection causes adverse pregnancy outcomes.