Apparent seroprevalence, isolation and identification of risk factors for brucellosis among dairy cattle in Goa, India

A study on the epidemiology of brucellosis in bovine population of peri-urban and rural areas of district Multan, southern Punjab, Pakistan

BACKGROUND

Brucellosis is a zoonotic disease caused by a bacterial pathogen belonging to the genus Brucella. It is one of the most frequent bacterial zoonoses globally but unfortunately, it is still considered as a neglected disease in the developing world. Keeping in view, this study was conducted to determine the prevalence and risk determinants of brucellosis in large ruminants of peri-urban and rural areas of district Multan-Pakistan. For this purpose, blood samples (n = 490) were collected from the cattle (n = 245) and buffalo (n = 245) population of the study area and subjected to preliminary screening of brucellosis using local and imported RBPT reagents. All the samples were further analyzed using commercially available multi-specie indirect ELISA kit followed by their confirmation by PCR using genus and species-specific primers. Data obtained from lab analysis and questionnaires were subjected to statistical analysis for Pearson Chi-square, Odds Ratio and Confidence intervals (95%).

RESULTS

The results showed that the maximum seropositivity was recorded with local RBPT reagent (VRI, Pakistan; 12.45%; 95%CI = 9.72-15.65%) followed by RBPT-IDEXX (12.24%; 95%CI = 9.52-15.45%) and RBPT-ID.vet (11.84%; 95%CI = 9.18-14.95%) however statistical difference was non-significant (P = 0.956). The ELISA results showed an overall seroprevalence rate of 11.22% (95%CI = 8.59-14.33%) with comparatively higher rate in cattle (12.65%; 95%CI = 8.82-17.44%) as compared to buffaloes (9.80%; 95%CI = 6.49-14.15%). The PCR analysis confirmed the presence of genus Brucella in all seropositive samples whereas frequency of B. abortus and B. melitensis in seropositive samples was 80% and 20%, respectively. The co-existence of both species was also observed in 5.45% samples. The statistical analysis showed a significant association of bovine brucellosis with herd size, breed, reproductive disorders, mode of insemination, educational status and farmers' awareness about brucellosis (P < 0.05). Conversely, locality, age, weight, gender, pregnancy status, parity and puberty status had no associations with brucellosis (P > 0.05).

CONCLUSION

In conclusion, brucellosis is prevalent in large ruminants of district Multan, Pakistan. It is suggested to devise and implement stringent policies for the effective control and prevention of brucellosis in the region. Further, the current situation also warrants the need to strengthen interdisciplinary coordination among veterinarians and physicians in one health perspective to ensure and strengthen the human and animal health care systems in the region.

Brucellae as resilient intracellular pathogens: epidemiology, host-pathogen interaction, recent genomics and proteomics approaches, and future perspectives

Brucellosis is considered one of the most hazardous zoonotic diseases all over the world. It causes formidable economic losses in developed and developing countries. Despite the significant attempts to get rid of Brucella pathogens in many parts of the world, the disease continues to spread widely. Recently, many attempts proved to be effective for the prevention and control of highly contagious bovine brucellosis, which could be followed by others to achieve a prosperous future without rampant Brucella pathogens. In this study, the updated view for worldwide Brucella distribution, possible predisposing factors for emerging Brucella pathogens, immune response and different types of Brucella vaccines, genomics and proteomics approaches incorporated recently in the field of brucellosis, and future perspectives for prevention and control of bovine brucellosis have been discussed comprehensively. So, the current study will be used as a guide for researchers in planning their future work, which will pave the way for a new world without these highly contagious pathogens that have been infecting and threatening the health of humans and terrestrial animals.

Evaluation of serological diagnostic tests for bovine brucellosis in dairy cattle herds in an endemic area: a multicenter study

Brucellosis is known as one of the most common zoonotic diseases worldwide affecting both livestock and humans. It causes abortions, reduces milk production, and infertility in infected animals. The disease is routinely diagnosed through three serological techniques, such as rose bengal plate test (RBPT), standard agglutination test (SAT), and indirect enzyme-linked immunosorbent assay (I-ELISA). The aim of this study was to identify and compare the brucellosis seroprevalence among dairy cattle farms through these different serological tests. From 2112 sampled dairy cattle in different parts of Iran, RBPT, SAT, and I-ELISA led to 296 (14.02%), 215 (10.18%), and 297 (14.06%) positive results, respectively. Brucella abortus biovar 3 (62 cases) was identified as the most common cause of brucellosis in tested animals. Our results showed that the specificity and sensitivity of I-ELISA were higher than those obtained by RBPT and SAT. In this study, the overall agreement of RBPT and SAT with I-ELISA reached 95.21% and 94.12% in dairy cattle farms, respectively. Furthermore, Cohen's kappa statistical analysis revealed that the best degree of agreement was seen between RBPT and I-ELISA (0.80), followed by RBPT and SAT (0.78) and finally SAT and I-ELISA (0.72), thereby indicating a strong agreement between RBPT and I-ELISA methods and good agreement between SAT and I-ELISA methods. The McNemar analysis also showed that a significant difference exists between positive and negative results determined by SAT and I-ELISA methods (p < 0.0001). However, the positive and negative results determined by I-ELISA and RBPT did not show a significant difference (p = 0.9207). Therefore, I-ELISA was a more specific and sensitive serological test when compared to RBPT and SAT and could remarkably decrease non-specific reaction by improving the serological screening specificity for an accurate brucellosis diagnosis in endemic areas.

Identifying potential natural inhibitors of Brucella melitensis Methionyl-tRNA synthetase through an in-silico approach

Background

Brucellosis is an infectious disease caused by bacteria of the genus Brucella. Although it is the most common zoonosis worldwide, there are increasing reports of drug resistance and cases of relapse after long term treatment with the existing drugs of choice. This study therefore aims at identifying possible natural inhibitors of Brucella melitensis Methionyl-tRNA synthetase through an in-silico approach.

Methods

Using PyRx 0.8 virtual screening software, the target was docked against a library of natural compounds obtained from edible African plants. The compound, 2-({3-[(3,5-dichlorobenzyl) amino] propyl} amino) quinolin-4(1H)-one (OOU) which is a co-crystallized ligand with the target was used as the reference compound. Screening of the molecular descriptors of the compounds for bioavailability, pharmacokinetic properties, and bioactivity was performed using the SWISSADME, pkCSM, and Molinspiration web servers respectively. The Fpocket and PLIP webservers were used to perform the analyses of the binding pockets and the protein ligand interactions. Analysis of the time-resolved trajectories of the Apo and Holo forms of the target was performed using the Galaxy and MDWeb servers.

Results

The lead compounds, Strophanthidin and Isopteropodin are present in Corchorus olitorius and Uncaria tomentosa (Cat’s-claw) plants respectively. Isopteropodin had a binding affinity score of -8.9 kcal / ml with the target and had 17 anti-correlating residues in Pocket 1 after molecular dynamics simulation. The complex formed by Isopteropodin and the target had a total RMSD of 4.408 and a total RMSF of 9.8067. However, Strophanthidin formed 3 hydrogen bonds with the target at ILE21, GLY262 and LEU294, and induced a total RMSF of 5.4541 at Pocket 1.

Conclusion

Overall, Isopteropodin and Strophanthidin were found to be better drug candidates than OOU and they showed potentials to inhibit the Brucella melitensis Methionyl-tRNA synthetase at Pocket 1, hence abilities to treat brucellosis. In-vivo and in-vitro investigations are needed to further evaluate the efficacy and toxicity of the lead compounds.

The cure for brucellosis involves a long course of treatment with a combination of antibiotics. However, some of the drugs are not recommended for very young children and pregnant women. Moreover, cases of relapse and resistance to these drugs are reported. With the Brucella Methionyl-tRNA synthetase as a target, molecular docking and virtual screening was used to identify possible drug candidates from a library of 1524 compounds obtained from edible African plants. Two lead compounds, Strophanthidin and Isopteropodin usually present in Corchorus olitorius and Uncaria tomentosa (Cat’s claw) plants showed potentials to inhibit the Brucella melitensis Methionyl-tRNA synthetase. Their bioactivities were also confirmed in their molecular dynamic simulation with the target protein. Consequently, both compounds have potentials for safety and efficacy in the treatment of brucellosis.

Importance of brucellosis control programs of livestock on the improvement of one health

Brucellosis not only represents an important health restraint on livestock but also causes high economic losses in many developing countries worldwide. Despite considerable efforts made for the control of brucellosis, the disease is still spreading in many regions (such as the Middle East) where it represents one of the most important health hazards impacting both animals and humans. The present review aims to investigate the efficacy of veterinary control programs regarding brucellosis, with a special focus on current prevention, control, and eradication approaches. The reasons for unsuccessful control programs such as the absence of highly effective vaccines and non-certified bulls are also debated, to understand why the prevalence of brucellosis in livestock is not decreasing in many areas despite considerable efforts taken to date. The importance of governmental and regional investment in brucellosis control remains one of the main limiting factors owing to the limited budget allocated to tackle this disease. In this context, one health concept has generated novel comprehensive approaches with multiple economic implications across the livestock industry and public health. However, the implementation of such global preventive strategies appears to be a key issue for many endemic and low-income countries. According to the collected data, epidemiological contexts including management and trade systems along with well-defined agro-ecological zones should be evaluated in brucellosis endemic countries to improve milk production and to enhance the sustainability of the livestock sector at both national and regional levels.

Bovine brucellosis - a comprehensive review

Brucellosis is a zoonotic disease of great animal welfare and economic implications worldwide known since ancient times. The emergence of brucellosis in new areas as well as transmission of brucellosis from wild and domestic animals is of great significance in terms of new epidemiological dimensions. Brucellosis poses a major public health threat by the consumption of non-pasteurized milk and milk products produced by unhygienic dairy farms in endemic areas. Regular and meticulous surveillance is essentially required to determine the true picture of brucellosis especially in areas with continuous high prevalence. Additionally, international migration of humans, animals and trade of animal products has created a challenge for disease spread and diagnosis in non-endemic areas. Isolation and identification remain the gold standard test, which requires expertise. The advancement in diagnostic strategies coupled with screening of newly introduced animals is warranted to control the disease. Of note, the diagnostic value of miRNAs for appropriate detection of B. abortus infection has been shown. The most widely used vaccine strains to protect against Brucella infection and related abortions in cattle are strain 19 and RB51. Moreover, it is very important to note that no vaccine, which is highly protective, safe and effective is available either for bovines or human beings. Research results encourage the use of bacteriophage lysates in treatment of bovine brucellosis. One Health approach can aid in control of this disease, both in animals and man.

The feasibility and acceptability of various bovine brucellosis control strategies in India

Bovine brucellosis is a neglected zoonotic disease prevalent in several developing countries including India. It has been successfully controlled in many developed countries by using vaccination in conjunction with extensive surveillance and test-and-cull approaches, but some of these approaches do not suit Indian culture and norms. This study was conducted to investigate the feasibility and social acceptability of various bovine brucellosis control strategies in India. Focus group discussions and key-informant interviews were conducted with veterinarians, para-veterinarians, veterinary academics, farmers and other stakeholders. Vaccination with the Brucella strain 19 vaccine was considered feasible, but the participants were concerned about the risk of self-inoculation, the inability to vaccinate pregnant and male animals, the difficulty to differentiate vaccinated from diseased animals and the challenges of maintaining the vaccine cold chain in India. As expected, the test-and-cull approach was not considered feasible as cattle are considered sacred by Hindus and their slaughter is banned in most states. Although the test-and-segregation approach appears reasonable in theory, it would have low acceptability, if implemented without providing any compensation to farmers. Negligible biosecurity was implemented by farmers: almost no biosecurity procedures were performed for visitors entering a farm, and testing of animals was rarely undertaken before introducing them to a farm. However, the participants considered that improving biosecurity would be more acceptable and feasible than both the test-and-cull and the test-and-segregation approaches. Similarly, inadequate personal protection was used by veterinary personnel for handling parturition, retention of placenta and abortion cases; this was considered as another area of possible improvement. Farmers and veterinarians expressed serious concerns about stray cattle as many of them could potentially be infected with brucellosis, and thus could spread the infection between farms. This study recommends using vaccination and biosecurity along with some ancillary strategies to control brucellosis in India. Information from the study could be used to develop an evidence-based disease control program for the disease in the country.

Seroprevalence and risk factors of brucellosis and the brucellosis model at the individual level of dairy cattle in the West Bandung District, Indonesia

Background and Aim

Brucellosis is a zoonotic bacterial infectious disease. West Bandung is a center for dairy farming in West Java Province District and endemic for brucellosis. The aim of the study was to determine the prevalence, the associated risk factors, and the brucellosis model at the individual level of dairy cattle in the West Bandung District.

Materials and Methods

The research was conducted through a cross-sectional study. The samples were collected from the serum blood of dairy cattle. Data obtained from the questionnaire were used to investigate risk factors. Multistage random sampling was applied as the sampling technique; therefore, a sample size of 540 cows was selected. The number of farms and cattle on each farm was calculated using a variant effect design of the farm as well as 108 farms was selected with five cattle samples per farm. The results in regard of the research sample acquisition in the West Bandung District included 588 dairy cows from 116 farms, exceeds the number of samples calculated (540 dairy cows and 108 farms). The rose Bengal test (RBT) and the complement fixation test (CFT) were performed for brucellosis testing. Data associated with brucellosis cases at the individual level of the dairy cattle were analyzed using descriptive statistics univariate, bivariate with Chi-square, and odds ratio (OR). Moreover, multivariate logistic regression was used for the analysis during modeling.

Results

The results showed that the prevalence of brucellosis at the individual level in the West Bandung District was 5.10%. Risk factors associated with brucellosis in cattle included the history of abortion (p=0.000; OR=9.9), the history of placental retention (p=0.000; OR=6.6), the history of endometritis (p=0.000; OR=5.5), the history of stillbirth (p=0.043; OR=3.0), the history of pregnancy abortion age at 7-8 months (p=0.000; OR=15.2), and the history of pregnancy abortion at the age of 4-6 months (p=0.007; OR=3.8). The model of brucellosis in dairy cows was the following: = -3.2843+3.41033 the history of pregnancy abortion at the age of 7-8 months +2.54503 the history of pregnancy abortion at the age of 4-6 months +1.86185 age of cattle >2 years - 1.0469 Calving interval 12 months. The model showed the factors that were associated with brucellosis at the individual level of dairy cattle included the history of pregnancy abortion at the age of 7-8 months (β=+3.41033; OR=30.3), the history of pregnancy abortion at the age of 4-6 months (β=+2.54503; OR=12.7); age of cattle >2 years (β=+1.86185; OR=1.2), and Calving interval ≤12 months (β=-1.04691; OR=0.34).

Conclusion

The results of this research showed that the prevalence of brucellosis at the individual level of dairy cattle in the West Bandung district was 5.10%. The risk factors could contribute to the increase of the brucellosis cases, that is, the history of pregnancy abortion at the age of 7-8, the history of pregnancy abortion at the age of 4-6 months, and the age of cattle >2 years. The risk factors can be decreased in the brucellosis cases, that is, calving intervals ≤12 months.

Serological evidence of Brucellosis in selected gaushalas of Haryana

Brucellosis is a neglected zoonotic disease with significant economic and public health consequences to human and animal population in developing countries. The objective of the present study was to determine the serological evidences of brucellosis in cattle reared in two gaushalas of Hisar and Jind districts, Haryana. The serological tests: Rose Bengal Plate Test (RBPT), Serum Agglutination Test (SAT) and Enzyme Linked Immunosorbent Assay (ELISA) were employed for screening the animals for brucellosis. The overall seropositivity by RBPT, SAT and ELISA was 23.46%, 20.67% and 28.49% respectively. The logistic regression modalities concluded higher likelihood of brucellosis with age > 6 years followed by 3–6 year than cows with <3 years. The agreement between tests (RBPT and ELISA, SAT and ELISA and RBPT and SAT) was found to be 0.87 (95% CI: 0.857–0.882), 0.70 (95% CI: 0.684–0.718) and 0.82 (95% CI: 0.809–0.834) respectively by kappa statistic. This study concluded high infection rate in gaushala where animals were kept as closed population with more risks of brucellosis among older milching animals which poses potential public health risk through consumption of unpasteurized milk.

A comparative study of serology and PCR for the diagnosis of brucellosis in goats

Brucellosis is an economically important infectious disease of livestock causing abortions, infertility, delayed oestrus, interrupted lactation, increased condemnation and loss of milk production besides its zoonotic nature. The present study was conducted to compare serological assays and polymerase chain reaction (PCR) for the diagnosis of caprine brucellosis. A total of 301 whole blood samples to extract DNA for PCR and serology were collected from goats maintained at various organized herds, panjarapoles, slaughter house, local meat markets, etc. in South Gujarat region of India. Out of 301 serum samples tested, 7 samples (2.33%) were positive by all the three serological tests, viz. rose bengal plate test (RBPT), indirect ELISA (iELISA) and immunochromatographic assay (ICA). Among 301 DNA samples, genus specific PCR detected DNA of Brucella spp. in 11 samples by targeting BCSP 31 and IS-711 genes to get 223 bp and 350 bp PCR products on agarose gel electrophoresis. None of the seven serologically positive samples showed Brucella genus-specific DNA amplification by PCR and similarly all PCR positive samples were negative on serology.

Associated factors in distinguishing patients with brucellosis from suspected cases

BACKGROUND

To investigate the risk factors for brucellosis in suspected cases of the disease.

METHODS

A self-designed questionnaire was developed to collect data from 3557 people whose initial visit site was the Songyuan Center for Disease Control and Prevention (CDC) from January 1st, 2009 to December 31st, 2012. After collecting blood samples, a plate agglutination test (PAT) and serum agglutination test (SAT) were used to distinguish the patients with brucellosis from the suspected cases.

RESULTS

Sex, occupation (farmers and herdsmen), contact with abortion products, and contact with feces were the main risk factors for brucellosis in the suspected cases (all P < 0.05). No difference existed between the confirmed cases and suspected cases in the demographic characteristics, contact with animals (except swine), contact with substances, or clinical symptoms (except fever). However, the confirmed cases showed significant differences from people without brucellosis in demographic characteristics, contact with animals (except cattle and swine), contact with substances, and clinical symptoms. Suspected cases exhibited significant differences from people without brucellosis in the demographic characteristics (except education), contact with animals (except swine), contact with substances (except dust), and clinical symptoms (except chills and acratia). Brucella was cultured from the blood samples of three of 30 suspected cases with fever. Using AMOS-PCR and agarose electrophoresis, the detailed species of Brucella strain was identified as Brucella melitensis.

CONCLUSIONS

Abortion products and feces are the main risk factors for brucellosis in suspected cases of the disease. Pyrexia in suspected cases with a history of contact with abortion products or feces should raise suspicion for the disease.

Multilocus variable number tandem repeat analysis (MLVA)-typing of Brucella abortus isolates of India reveals limited genetic diversity

Multilocus variable number tandem repeat analysis (MLVA) technique has wide applications in studying phylogenies and short-term epidemiology of pathogens. The technique has been extensively used worldwide in molecular epidemiology of Brucella genus. Only one study on this aspect is reported from India despite its economic and public health significance in country. The present study isolated B. abortus from domesticated bovines of Jammu region of Jammu and Kashmir state, India, and applied MLVA for 16 loci (MLVA-16). MLVA results were compared with the results of a previous study and with MLVA data of Indian isolates present in http://microbesgenotyping.i2bc.paris-saclay.fr/database. In the study, 136 samples from bovines (cattle and buffaloes) of 47 farms of Jammu region were processed for isolation. Eleven isolates of B. abortus biovar 1 from 6 farms were obtained. In MLVA-16 analysis, although the isolates were classified in a single cluster, 5 genotypes were obtained with a specific genotype being prevalent on each farm. The study identifies that MLVA-16 is capable to differentiate B. abortus strains in an area having high genetic similarity among isolates. On comparing the results with previous study and database, the isolates were found to have high genetic similarity indicating that the genetic diversity of B. abortus in India is very limited. It probably indicates that India is contaminated recently with B. abortus. To test this hypothesis, analysis of whole genome sequencing data of diverse collection of Indian B. abortus strains is required.

Reasons behind the epidemiological situation of brucellosis in the Republic of Kazakhstan

Brucellosis is endemic in the Republic of Kazakhstan, particularly in agro-pastoral areas. The purpose of this research is to study the epidemiological situation of brucellosis in livestock recorded in the Republic of Kazakhstan, and to identify the reasons why anti-brucellosis measures were not effective. The research was performed on statistical data provided by the Republican Veterinary Laboratory (RVL), the Ministry of Agriculture of the Republic of Kazakhstan. The analysis touched upon the prevalence of Brucellosis in cattle and small ruminants (sheep and goats) in 13 regions of the Republic of Kazakhstan in 2012-2016. Aside from that, Research Institute for Biological Safety Problems conducted screening assays that involved 11,889 samples of blood and tissues from said animals. The risks of developing Brucellosis were assessed for each particular region. The comparison of studies conducted in 2012-2016 reveals an increase in the prevalence of Brucellosis in cattle in the following regions: West Kazakhstan, Karaganda Region and Pavlodar Region. For small ruminants, growing prevalence was observed in the Kostanay Region, Jambyl Region and Almaty Region. Between 2014 and 2016, the incidence rate had a growing trend, with a high in 2014 and 2015. The lowest prevalence rate during the following years (2012-2016) was in the Mangystau Region. The Enzyme-Linked Immunosorbent Assay (ELISE) test applied in the research among other tests provided the best results. The main risk factors involve epidemiology and sanitary measures, which are undertaken in the Republic of Kazakhstan, geography of the region with focuses of infection, and randomness of spread.

Analysis of the risk factors for bovine brucellosis in dairy herds of the Rio Branco microregion, Acre, Brazil

ABSTRACT Bovine brucellosis (BB) is a compulsory notifiable bacterial disease caused by Brucella abortus, which is responsible for severe reproductive disorders in cattle, considerable damages to trade and public health damage. The objectives of this study were to identify the frequency of BB and to analyze the risk factors in the dairy herds of the Rio Branco microregion, in the state of Acre, Brazil. Thus, 527-bovine-serological samples were submitted to the buffered acidified antigen test and to 2-mercaptoethanol. Risk factors were characterized by the administration of epidemiological questionnaires. The logistic regression test was used to evaluate the existence of a significant association between the variables. The frequency of BB in the Rio Branco microregion was 10.6% (56/527). The inappropriate destination of the aborted fetus and placental remnants (odds ratio — OR = 13.6), the slaughter of cattle within the property (OR = 3.4) and the age range above 4 years old (OR = 2.9) were the most significant risk factors identified by the logistic regression model. According to the results of this study, it is recommended to intensify BB control and prophylaxis measures in the microregion of Rio Branco, especially those related to sanitary and reproductive management in the livestock breeding.

Brucellosis seroprevalence in dairy cattle in China during 2008-2018: A systematic review and meta-analysis

Brucellosis remains one of the most common zoonotic diseases globally with more than a half million human cases reported annually. The Brucella reservoir associated with livestock brucellosis poses a significant threat to public health, and awareness of the seroprevalence and spatial distribution of livestock brucellosis is valuable for the prevention and control of diseases caused by Brucella, especially human brucellosis. Therefore, we conducted a systematic review and meta-analysis to evaluate the seroprevalence of brucellosis in dairy cattle in China. We retrieved 88 studies related to the seroprevalence of brucellosis in dairy cattle in China in which samples were harvested between 2008 and 2018. The results of our systematic review and meta-analysis reveal that the overall seroprevalence of brucellosis in dairy cattle herds in China was 1.9% during the selected period, rising from 1.6% in 2008-2012 to 2.6% in 2013-2018. In Northern China, where the traditional agropastoral areas with more developed animal breeding industry are located, the brucellosis seroprevalence was >10%. In contrast, the seroprevalence of brucellosis in Southern China reached only 5.5%. At the provincial level, the highest brucellosis seroprevalence in dairy cattle was estimated at >30% in Jilin province, followed by Shanxi, Ningxia, Inner Mongolia, and Guizhou, each with a prevalence of 10-20%. Additionally, the seroprevalence of brucellosis in some local areas was >30% or even >50%, indicating that Brucella infection was highly endemic in dairy herds in China. Our data may facilitate the prevention and control of brucellosis in domestic animals in China. Further epidemiological surveillance and the administration of a comprehensive monitoring program to determine the risk factors associated with brucellosis incidence in humans and domestic animals are recommended to refine brucellosis control strategies.