Genomic Diversity and Zoonotic Potential of Brucella neotomae.

After reports in 2017 of Brucella neotomae infections among humans in Costa Rica, we sequenced 12 strains isolated from rodents during 1955-1964 from Utah, USA. We observed an exact strain match between the human isolates and 1 Utah isolate. Independent confirmation is required to clarify B. neotomae zoonotic potential.

National epidemiology of culture-confirmed brucellosis in Israel, 2004-2022.

Brucellosis, a global zoonosis, is endemic in Israel. We used a national database of culture-confirmed cases (2004-2022) to analyse the trends of brucellosis. Of 2,489 unique cases, 99.8% were bacteraemic, 64% involved males, and the mean age was 30.5 years. Brucella melitensis was the dominant species (99.6%). Most cases occurred among the Arab sector (84.9%) followed by the Jewish (8.5%) and Druze (5.5%) sectors. The average annual incidence rates overall and for the Arab, Druze, and Jewish sectors were 1.6/100,000, 6.6/100,000, 5.5/100,000, and 0.18/100,000, respectively. The annual incidence rates among the Arab (incidence rate ratio (IRR) = 36.4) and the Druze (IRR = 29.6) sectors were significantly higher than among the Jewish sector (p < 0.001). The highest incidence rates among the Arab sector occurred in the South District, peaking at 41.0/100,000 in 2012. The frequencies of B. melitensis isolated biotypes (biotype 1 - 69.1%, biotype 2 - 26.0%, and biotype 3 - 4.3%) differed from most Middle Eastern and European countries. A significant switch between the dominant biotypes was noted in the second half of the study period. Efforts for control and prevention should be sustained and guided by a One Health approach mindful of the differential trends and changing epidemiology.

Spatiotemporal dynamics and influencing factors of human brucellosis in Mainland China from 2005-2021.

BACKGROUND: Brucellosis poses a significant public health concern. This study explores the spatial and temporal dynamic evolution of human brucellosis in China and analyses the spatial heterogeneity of the influencing factors related to the incidence of human brucellosis at the provincial level. METHODS: The Join-point model, centre of gravity migration model and spatial autocorrelation analysis were employed to evaluate potential changes in the spatial and temporal distribution of human brucellosis in mainland China from 2005 to 2021. Ordinary Least Squares (OLS), Geographically Weighted Regression (GWR), and Multi-scale Geographically Weighted Regression (MGWR) models were constructed to analyze the spatial and temporal correlation between the incidence rate of human brucellosis and meteorological and social factors. RESULTS: From 2005 to 2021, human brucellosis in China showed a consistent upward trend. The incidence rate rose more rapidly in South, Central, and Southwest China, leading to a shift in the center of gravity from the North to the Southwest, as illustrated in the migration trajectory diagram. Strong spatial aggregation was observed. The MGWR model outperformed others. Spatio-temporal plots indicated that lower mean annual temperatures and increased beef, mutton, and milk production significantly correlated with higher brucellosis incidence. Cities like Guangxi and Guangdong were more affected by low temperatures, while Xinjiang and Tibet were influenced more by beef and milk production. Inner Mongolia and Heilongjiang were more affected by mutton production. Importantly, an increase in regional GDP and health expenditure exerted a notable protective effect against human brucellosis incidence. CONCLUSIONS: Human brucellosis remains a pervasive challenge. Meteorological and social factors significantly influence its incidence in a spatiotemporally specific manner. Tailored prevention strategies should be region-specific, providing valuable insights for effective brucellosis control measures.

Molecular examination for Coxiella burnetii and Brucella spp. infections in Iranian women experiencing spontaneous miscarriage.

BACKGROUND: Spontaneous miscarriage, a leading health concern globally, often occurs due to various factors, including infections. Among these, Coxiella burnetii and Brucella spp. may have adverse effects on pregnancy outcomes. While previous research has established a link between infections and spontaneous miscarriage, our study aimed specifically to investigate the presence of these two pathogens in abortion samples from women who experienced spontaneous miscarriages in Iran. Our study can add to the existing knowledge by focusing on Iran, a region with a high prevalence of C. burnetii and Brucella spp. As a result, it could provide a better understanding and unique insights into the relationship of these pathogens with spontaneous miscarriages in endemic regions. METHODS: From March 2021 to March 2022, a total of 728 abortion samples (including placenta and cotyledon) were collected from 409 women who had experienced spontaneous miscarriages in the provinces of Tehran, Fars, and West Azerbaijan in Iran. The specimens included 467 Formalin-Fixed Paraffin-Embedded (FFPE) and 261 fresh frozen samples. After DNA extraction from abortion samples, the quantitative real-time PCR (qPCR) assay targeted a specific fragment of the IS1111 and IS711 elements for molecular identification of C. burnetii and Brucella spp., respectively. Furthermore, the qPCR assay employing specific primers for different species was used to determine the species of Brucella. RESULTS: Among the studied women, 1 out of 409 (0.24%) samples tested positive for Brucella spp., specifically Brucella melitensis. There were no positive specimens for C. burnetii. CONCLUSIONS: Our study contributes to understanding the potential involvement of Brucella species in spontaneous infectious abortion within endemic regions. The identification of B. melitensis in this study highlights the need for further research in this area. However, while our results suggest a relatively low or zero identification of these pathogens in our sample population, this does not rule out the possibility of undetected infections. Therefore, it is critical to acknowledge the limitations of the molecular techniques used (qPCR), which may have potential limitations such as sensitivity and specificity. Moreover, because 64.15% of our samples were FFPE, the sensitivity of the qPCR test may be reduced. These raise concerns about the accuracy of the reported prevalence rates and the potential for false positives or negatives.

Spatiotemporal distribution and ecological factors of brucellosis among children from 2016 to 2020 in Inner Mongolia, China.

OBJECTIVE: In recent years, the increasing incidence of brucellosis in children has become more serious. However, relatively few studies have been conducted to characterize the spatialtemporal distribution of brucellosis in children. This study aimed to analyze the spatiotemporal distribution characteristics and ecological influencing factors of brucellosis incidence among children in Inner Mongolia. METHODS: This study used data on brucellosis incidence in children aged 0-14 years reported in Inner Mongolia from 2016 to 2020. A Bayesian model was used to analyze the spatial and temporal distribution of brucellosis in children from 2016 to 2020 in Inner Mongolia. Geographical weighted regression model was used to analyze the ecological factors related to the incidence of brucellosis in children. RESULT: Bayesian spatiotemporal analysis indicated that the highest brucellosis risk and increased disease incidence were observed in Hinggan, Inner Mongolia, in children aged 0-14 years. Alxa had the lowest risk but the incidence rate increased rapidly. The incidence of childhood brucellosis was positively associated with the number of sheep at the year-end (ß: 2.5909 ~ 2.5926, P < 0.01), average temperature (ß: 2.8978 ~ 2.9030, P < 0.05), and precipitation level (ß: 3.3261 ~ 3.3268, P < 0.01). CONCLUSION: From 2016 to 2020, the overall incidence of brucellosis in children in Inner Mongolia showed an upward trend, with cases exhibiting spatial aggregation. We should focus on areas where the incidence of brucellosis in children is rising rapidly. The incidence of childhood brucellosis was associated with the number of sheep at the year-end, average temperature and precipitation level. IMPLICATIONS AND CONTRIBUTION: The findings suggest that brucellosis in children is not to be taken lightly. For children should also focus on protection, take corresponding protective measures. While we focus on high-risk areas, we must also monitor areas where the risk of disease is low, but the incidence is rising fast, to prevent outbreaks in low-risk areas from becoming high-risk areas.

Clinical characterization of brucellosis in children from non-pastoral areas: a report of five cases.

BACKGROUND: Brucellosis is a global public health concern and occurs mainly in young adults and the elderly, with children having a lower incidence, thus often leading to delayed treatment. This study aimed to describe the epidemiologic features and clinical characteristics of brucellosis in children. METHODS: In this retrospective study, the clinical data of five children diagnosed with brucellosis in Anhui Provincial Children's Hospital between January 1, 2021 and December 30, 2022 were analyzed. RESULTS: All five cases were from non-pastoral areas, among which three have a history of livestock exposure and originated from the countryside. All patients had medium-high grade fever, mostly accompanied by night sweats and malaise, and three had joint pains. Laboratory tests showed that their white blood cell count was normal or mildly raised, with lymphocytes as the predominant cell population. Four patients had anemia, four had aspartate aminotransferase and alanine aminotransferase abnormality, and two had elevated ferritin levels. All blood samples were positive for Brucella culture, one of which had positive bone marrow culture, and all had positive serology test results. All patients were treated with rifampicin, in combination with sulfamethoxazole or doxycycline for 6 weeks following diagnosis. Four children had a good prognosis, but one child had recurrent joint pain. CONCLUSIONS: The epidemiologic history of children from non-pastoral areas with brucellosis is often unclear; clinical manifestations and laboratory tests lack specificity; and they are easily delayed diagnosis. Clinicians should remain vigilant regarding the possibility of this disease in children with fever of unknown origin. The epidemiological history should be investigated in detail to improve the diagnostic ability of brucellosis. We recommend emphasizing serological testing. Children with brucellosis who receive timely diagnosis and standardized treatment can expect a favorable prognosis.

Chronic meningitis in adults: a comparison between neurotuberculosis and neurobrucellosis.

BACKGROUND: In regions endemic for tuberculosis and brucellosis, distinguishing between tuberculous meningitis (TBM) and brucella meningitis (BM) poses a substantial challenge. This study investigates the clinical and paraclinical characteristics of patients with TBM and BM. METHODS: Adult patients diagnosed with either TBM or BM who were admitted to two referral hospitals between March 2015 and October 2022, were included, and the characteristics of the patients were analyzed. RESULTS: Seventy patients formed the study group, 28 with TBM and 42 with BM, were included. TBM patients had a 2.06-fold (95% CI: 1.26 to 3.37, P-value: 0.003) higher risk of altered consciousness and a 4.80-fold (95% CI: 1.98 to 11.61, P-value: < 0.001) higher risk of extra-neural involvement as compared to BM patients. Cerebrospinal fluid (CSF) analysis revealed a significantly higher percentage of polymorphonuclear leukocytes (PMN) in TBM compared to BM (Standardized mean difference: 0.69, 95% CI: 0.18 to 1.20, P-value: 0.008). Neuroimaging findings indicated higher risks of hydrocephalus (P-value: 0.002), infarction (P-value: 0.029), and meningeal enhancement (P-value: 0.012) in TBM compared to BM. Moreover, TBM patients had a 67% (95% CI: 21% to 131%, P-value:0.002) longer median length of hospital stay and a significantly higher risk of unfavorable outcomes (Risk ratio: 6.96, 95% CI: 2.65 to 18.26, p < 0.001). CONCLUSIONS: Our study emphasizes that TBM patients displayed increased frequencies of altered consciousness, PMN dominance in CSF, extra-neural involvement, hydrocephalus, meningeal enhancement, and brain infarction. The findings emphasize the diagnostic difficulties and underscore the importance of cautious differentiation between these two conditions to guide appropriate treatment strategies.

Neurobrucellosis: laboratory features, clinical characteristics, antibiotic treatment, and clinical outcomes of 21 patients.

BACKGROUND: Neurobrucellosis (NB) is a rare and serious complication of brucellosis. Its clinical manifestations vary, with no obvious specificity. At present, there is no clear clinical diagnosis or treatment for reference. In this study, we retrospectively analyzed the clinical data for 21 patients with NB to provide reference data for its further study. METHODS: We analyzed the epidemiological and clinical manifestations, laboratory tests, imaging examinations, cerebrospinal fluid, and treatment plans of 21 patients diagnosed with NB in the Department of Neurology, Xuanwu Hospital, Capital Medical University Beijing, China. RESULTS: The ages of the patients ranged from 15 to 60 years old (mean age 40.1 ± 13.33 years), the male: female ratio was 4.25:1. Thirteen patients had a history of animal (sheep, cattle) contact, three had no history of animal contact, and the contact status of four was unknown. Brucella can invade various systems of the body and show multi-system symptoms, the main general manifestations were fever (66.67%), fatigue (57.14%) and functional urination or defecation disturbance (42.86%). The main nervous system manifestations were limb weakness (52.38%) and hearing loss (47.62%).The main positive signs of the nervous system included positive pathological signs (71.43%), sensory abnormalities (52.38%), limb paralysis (42.86%). Nervous system lesions mainly included spinal cord damage (66.67%), cranial nerve involvement (61.90%), central demyelination (28.57%) and meningitis (28.57%). In patients with cranial nerve involvement, 69.23% of auditory nerve, 15.38% of optic nerve and 15.38% of oculomotor nerve were involved. The blood of eight patients was cultured for Brucella, and three (37.5%) cultures were positive and five (63.5%) negative. The cerebrospinal fluid (CSF) of eight patients was cultured for Brucella, and two (25.00%) cultures were positive and six (75.00%) negative. Nineteen of the patients underwent a serum agglutination test (SAT), 18 (94.74%) of whom were positive and one (5.26%) of whom were negative. A biochemical analysis of the CSF was performed in 21 patients, and the results were all abnormal. Nineteen patients underwent magnetic resonance imaging (MRI). Twenty-one patients were treated with doxycycline and/or rifampicin, combined with ceftriaxone, quinolone, aminoglycoside, or minocycline. After hospitalization, 15 patients improved (71.43%), two patients did not recover, and the status of four patients was unknown. CONCLUSIONS: The clinical manifestations, CSF parameters, and neurological imaging data for patients with NB show no significant specificity or correlations. When patients with unexplained neurological symptoms accompanied by fever, fatigue, and other systemic manifestations in a brucellosis epidemic area or with a history of contact with cattle, sheep, animals, or raw food are encountered in clinical practice, the possibility of NB should be considered. Treatment is based on the principles of an early, combined, and long course of treatment, and the general prognosis is good.

Molecular epidemiological characteristics of osteoarthritis-associated Brucella melitensis in China: evidence from whole-genome sequencing-based analysis.

BACKGROUND: Brucellosis, developing complications including arthritis, spondylitis, sacroiliitis, and osteomyelitis, is one of the most common zoonotic diseases in the current world which causes economic losses to the livestock industry and is a great public health concern. Brucella melitensis are the main pathogen of brucellosis epidemics in China, most of which are located in northern China. However, there is limited knowledge about the epidemiology of osteoarthritis-associated brucellosis. This study was aimed to reveal the prevalence of osteoarthritis-associated brucellosis in Inner Mongolia and also to investigate the molecular characteristics of B. melitensis isolates. METHODS AND RESULTS: In 2018, the osteoarthritis symptoms of brucellosis in the Brucellosis department of a hospital in Inner Mongolia were investigated. Twenty osteoarthritis-associated B. melitensis strains, isolated from the inpatients in Inner Mongolia during 2013-2017, were subjected to whole genome sequencing. The multilocus sequence type (MLST) and core genome SNP (cgSNP) analysis were conducted to detect molecular epidemiological characteristics. The incidence of brucellosis osteoarthritis symptoms in males (85/120, 70.8%) was significantly higher than that in females (35/120, 29.2%), and the age of patients was concentrated between 41 and 60 years old. In silico analyses indicated ST8 was the prevalent sequence type and the transmission of osteoarthritis-associated B. melitensis among different geographical areas. All strains carry virulence genes, including cgs, lpsA, manCoAg, pgm, pmm, virB4, wbdA and wboA. CONCLUSION: Our study showed the close epidemiologically connection of osteoarthritis-associated B. melitensis strains in northern China. And ST8 was the prevalent sequence type which need our attention.

Analysis of the Brucella melitensis epidemic in Xinjiang: genotyping, polymorphism, antibiotic resistance and tracing.

Brucella spp. are facultative intracellular pathogens that cause zoonosis- brucellosis worldwide. There has been a trend of the re-emergence of brucellosis worldwide in recent years. The epidemic situation of brucellosis is serious in Xinjiang. To analyze the epidemic situation of Brucella spp. in Xinjiang among humans and animals, this study identified 144 Brucella isolates from Xinjiang using classical identification and 16 S rRNA sequencing. MLVA, drug resistance testing, and wgSNP detection were also performed. At the same time, analysis was conducted based on the published data of Brucella isolates worldwide. The results showed that the dominant species was B. melitensis biovar 3, which belonged to GT42 (MLVA-8 typing) and the East Mediterranean lineage. The correlation among isolates was high both in humans or animals. The isolates in Xinjiang exhibited higher polymorphism compared to other locations in China, with polymorphism increasing each year since 2010. No amikacin/kanamycin-resistant strains were detected, but six rifampicin-intermediate isolates were identified without rpoB gene variation. The NJ tree of the wgSNP results indicated that there were three main complexes of the B. melitensis epidemic in Xinjiang. Based on the results of this study, the prevention and control of brucellosis in Xinjiang should focus on B. melitensis, particularly strains belonging to B. melitensis bv.3 GT42 (MLVA-8 typing) and East Mediterranean lineage. Additionally, the rifampicin- and trimethoprim-sulfamethoxazole- resistance of isolates in Xinjiang should be closely monitored to avoid compromising the therapeutic efficacy and causing greater losses. These results provide essential data for the prevention and control of brucellosis in Xinjiang and China. Although the isolates from Xinjiang have significant characteristics among Chinese isolates and can reflect the epidemiological situation of brucellosis in China to some extent, this study cannot represent the characteristics of isolates from other regions.

Stability of a stochastic brucellosis model with semi-Markovian switching and diffusion.

To explore the influence of state changes on brucellosis, a stochastic brucellosis model with semi-Markovian switchings and diffusion is proposed in this paper. When there is no switching, we introduce a critical value R s and obtain the exponential stability in mean square when R s < 1 by using the stochastic Lyapunov function method. Sudden climate changes can drive changes in transmission rate of brucellosis, which can be modelled by a semi-Markov process. We study the influence of stationary distribution of semi-Markov process on extinction of brucellosis in switching environment including both stable states, during which brucellosis dies out, and unstable states, during which brucellosis persists. The results show that increasing the frequencies and average dwell times in stable states to certain extent can ensure the extinction of brucellosis. Finally, numerical simulations are given to illustrate the analytical results. We also suggest that herdsmen should reduce the densities of animal habitation to decrease the contact rate, increase slaughter rate of animals and apply disinfection measures to kill brucella.

The Reasons Behind Long-Term Endemicity of Brucellosis in Low and Middle-Income Countries: Challenges and Future Perspectives.

Brucellosis is a neglected worldwide zoonotic disease with more than 500,000 new human cases each year. Direct contact with infected animals and consumption of undercooked animal origin foods are the main routes of brucellosis transmission to humans. Although long endeavor has been applied to control and eliminate brucellosis from animal and human populations in developing countries especially in low- and middle-income countries (LMICs), the disease is still endemic in these regions. Many common or unique factors including raw milk consumption, unhygienic slaughter of livestock, extensive husbandry, budgetary limitations, misdiagnosis, and other conditions play a role in long-term endemicity of brucellosis in these locations. It has been shown that One Health is the only practical approach to control brucellosis; however, applying such methods is challenging in low-resource areas. In such conditions, brucellosis is continuously maintained in animals and repeatedly spread to human populations. In this article, factors playing a critical role in brucellosis endemicity, and the real conditions challenging the application of One Health approach in control of brucellosis are highlighted.

Genomic analysis of Brucella isolates from animals and humans, Türkiye, 2010 to 2020.

BackgroundBrucellosis is a bacterial zoonosis causing severe illness in humans and animals and leading to economic losses in the livestock production in Türkiye and other endemic countries.AimWe aimed at investigating genomic differences of Brucella isolates from animals and humans in Türkiye.MethodsWe used whole genome sequencing (WGS) to assess the genetic diversity of Brucella isolates from 41 provinces in Türkiye and compared with isolates from other countries. We applied allele-based typing and core genome single nucleotide polymorphism (cgSNP) determination.ResultsOf the 106 Turkish Brucella isolates included, 57 were B. abortus and 49 were B. melitensis. One B. melitensis and two B. abortus isolates were identified as vaccine strains. Most (n = 55) B. abortus isolates clustered in three major branches, with no spatial discernible pattern. Of the B. melitensis isolates, 48 were assigned to the Eastern Mediterranean lineage with no discernible patterns between host species, location and sampling date. The Turkish isolates clustered with isolates from neighbouring countries such as Greece and Syria, but some also with isolates from human patients in European countries, like Germany, Norway and Sweden, suggesting that the source may be travel-related.ConclusionSeveral B. melitensis and B. abortus lineages are circulating in Türkiye. To decrease the prevalence and prevent brucellosis in animals and humans, stricter control measures are needed, particularly in areas where humans and animals have close contact. Furthermore, illegal transportation of animals across borders should be more closely controlled and regulated.

Long COVID: Alice Evans, Brucellosis, and Reflections on Infectious Causes of Chronic Disease.

Despite more than a century of research on the link between infection and chronic diseases, we again find ourselves flummoxed by a new pathogen that causes long-term impairment. Patients have reported being ignored or minimized, resources are lacking for diagnosis and treatment, and frustrated individuals are turning outside of the scientific profession for answers. The experience mirrors that of American Society for Microbiology past president Alice C. Evans. Accidentally infected with Brucella melitensis during her laboratory research, Evans was chronically ill for more than 20 years, during which time friends, colleagues, and physicians cast doubt on her illness. As a result, she argued passionately for improved diagnostics and for those who reported chronic infection to be taken seriously rather than presumed to be "malingering" or using their illness for financial benefit. Lessons from Evans' experience are useful as we work toward understanding long COVID and patients suffering from the condition.

Global Estimate of Human Brucellosis Incidence.

Brucellosis is a major public health concern worldwide, especially for persons living in resource-limited settings. Historically, an evidence-based estimate of the global annual incidence of human cases has been elusive. We used international public health data to fill this information gap through application of risk metrics to worldwide and regional at-risk populations. We performed estimations using 3 statistical models (weighted average interpolation, bootstrap resampling, and Bayesian inference) and considered missing information. An evidence-based conservative estimate of the annual global incidence is 2.1 million, significantly higher than was previously assumed. Our models indicate Africa and Asia sustain most of the global risk and cases, although areas within the Americas and Europe remain of concern. This study reveals that disease risk and incidence are higher than previously suggested and lie mainly within resource-limited settings. Clarification of both misdiagnosis and underdiagnosis is required because those factors will amplify case estimates.

Novel Species of Brucella Causing Human Brucellosis, French Guiana.

Human brucellosis is a zoonoses caused by bacteria of the genus Brucella. Infection results in subacute or chronic debilitating disease with nonspecific clinical manifestations and is often associated with consuming unpasteurized dairy products. We report 2 cases of brucellosis in male patients who were hospitalized in distinct towns of French Guiana, an overseas territory of France located on the northeastern shore of South America. Both men were citizens of Brazil working as clandestine goldminers in the deep Amazonian rainforest. Characterization of the 2 bacterial isolates revealed that they represent a potential new species of Brucella. Medical practitioners working in contact with wildlife in this region of the world should be aware of the existence of these pathogens and the potential for human infection.

Neurobrucellosis.

PURPOSE OF REVIEW: Brucellosis is one of the most common zoonosis worldwide, affecting 500 000 people, annually. Neurobrucellosis incidence is approximately 4%, and it is almost always heterogeneous. As there are no typical clinical features, its diagnosis is frequently misdiagnosing by other infections. RECENT FINDINGS: Neurobrucellosis picture includes meningitis, meningoencephalitis, encephalitis, cranial neuropathies, intracranial hypertension, sinus thrombosis, hemorrhages radiculitis, peripheral neuropathy, myelitis, and psychiatric manifestations. The diagnosis should be based on symptoms and signs suggestive of neurobrucellosis, not explained by other neurological disease, cerebrospinal fluid analysis, a positive Brucella serology or culture, and a response to specific antibiotics, with a significant improvement of cerebrospinal fluid parameters. SUMMARY: Neurobrucellosis can be insidious, and despite its global distribution, it is still unrecognized and frequently goes unreported. The understanding of the current epidemiology is necessary for eradication of the disease in humans, as well as the disease control in animals and prevention based on occupational hygiene and food hygiene.

Comparative evaluation of RBPT, I-ELISA, and CFT for the diagnosis of brucellosis and PCR detection of Brucella species from Ethiopian sheep, goats, and cattle sera.

BACKGROUND: Brucellosis is an economically devastating animal disease and has public health concern. Serological methods such as Rose Bengal Plate Test (RBPT), Complement Fixation Test (CFT), and Indirect-Enzyme-Linked Immunosorbent Assay (I-ELISA) have been used to detect brucellosis. However, there is limited comparative evaluation studies and lack of molecular confirmation of the causative agents in the study areas. The study was aimed to compare RBPT, I-ELISA, CFT, and confirmation using Polymerase Chain Reaction (PCR). A total of 2317 sera samples were collected from brucellosis-affected areas of Ethiopia with no vaccination history. All sera were subjected to comparative serological assays. Post-cross tabulation, sensitivity, and specificity were determined using Receiver Operating Characteristics (ROC) curve analysis software. PCR was performed on 54 seropositive samples using genus- and species-specific primers. RESULTS: Among the 2317 sera tested for comparative serological assays, 189 (8.16%) were positive for RBPT, 191 (8.24%) for I-ELISA, and 48 (2.07%) for CFT. Sensitivity to RBPT was 100% (95%) in shoats and 74% (95%) in cattle. Specificity on RBPT was 98.69% (95%), 99.28% (95%), 100% (95%) in sheep, goats, and cattle, respectively. CFT sensitivity was 4 (95%) in sheep, 9.65 (95%) goats, and 72 (95%) cattle. Specificity on CFT was 100% (95%) for sheep, goats, and cattle. A 223bp Brucella genus-specific and 156bp B. abortus species-specific detected. However, B. melitensis not detected. CONCLUSION: In this study, I-ELISA was the most sensitive and specific test. RBPT detected all Brucellosis-infected sheep and goats; nevertheless, it showed false positive in sheep and goats and false negative in cattle. The presence of B. abortus in small and large ruminants was confirmed by PCR. This is the first report of B. abortus detection in small ruminant in Ethiopia. B.abortus detected in non-preferred hosts. The findings suggest further study on molecular epidemiology of Brucella species.

Prevalence of Brucella melitensis and Brucella abortus tetracyclines resistance: A systematic review and meta-analysis.

INTRODUCTION: Brucellosis is a zoonotic disease that can be transmitted from animals to humans. Brucellosis is caused by bacteria of the genus Brucella, which are typically transmitted through contact with infected animals, unpasteurized dairy products, or airborne pathogens. Tetracyclines (tetracycline and doxycycline) are antibiotics commonly used to treat brucellosis; however, antibiotic resistance has become a major concern. This study assessed the worldwide prevalence of tetracycline-resistant Brucella isolates. METHODS: A systematic search was conducted in Scopus, PubMed, Web of Science, and EMBASE using relevant keywords and Medical Subject Headings (MeSH) terms until August 13, 2022, to identify relevant studies for meta-analysis. A random effects model was used to estimate the proportion of resistance. Meta-regression analysis, subgroup analysis, and examination of outliers and influential studies were also performed. RESULTS: The prevalence rates of resistance to tetracycline and doxycycline were estimated to be 0.017 (95% confidence interval [CI], 0.009-0.035) and 0.017 (95%CI, 0.011-0.026), respectively, based on 51 studies conducted from 1983 to 2020. Both drugs showed increasing resistance over time (tetracycline: r = 0.077, P = 0.012; doxycycline: r = 0.059, P = 0.026). CONCLUSION: The prevalence of tetracycline and doxycycline resistance in Brucella was low (1.7%) but increased over time. This increase in tetracycline and doxycycline resistance highlights the need for further research to understand resistance mechanisms and develop more effective treatments.

The canonical Brucella species-host dependency is changing, however, the antibiotic susceptibility profiles remain unchanged.

Brucellosis is a chronic disease caused by Brucella species with a wide range of hosts, from marine mammals to terrestrial species, but with strict host preferences. With the zoonotic character, the prevalence of human brucellosis cases is a reflection of animal infections. This study aimed to identify 192 Brucella isolates obtained from various sources by Bruce-ladder PCR and to determine their antibiotic susceptibilities by gradient diffusion method (E-test). As a result of the PCR, all human isolates (n = 57) were identified as B. melitensis. While 58 (82.9%) of the cattle isolates were identified as B. abortus, 59 (90.8%) of the sheep isolates were identified as B. melitensis. In addition, 12 (17.1%) of the cattle isolates and 6 (9.2%) of the sheep isolates were determined as B. melitensis and B. abortus, respectively. The primary host change behavior of B. melitensis was 1.9 times higher than that of B. abortus. While gentamicin and ciprofloxacin susceptibilities of Brucella isolates were 100%, tetracycline, doxycycline, streptomycin, trimethoprim/sulfamethoxazole and rifampicin susceptibilities were 99%, 99%, 97.4%, 91.7% and 83.9%, respectively. The lowest sensitivity of the isolates was determined against to cefoperazone as 26%. A triple-drug resistance was detected in 1 B. abortus isolate that included simultaneous resistance to cefoperazone, rifampicin, and trimethoprim/sulfamethoxazole. The high susceptibility profiles we found against to antibiotics such as tetracycline, doxycycline gentamicin and ciprofloxacin, used widely in treatment, are encouraging. However, the change in the canonical Brucella species-primary host preference suggests the need to reconsider eradication program, including updating vaccine formulations.