Coxiella burnetii associated reproductive disorders in domestic animals-a critical review

The bacterium Coxiella burnetii has been detected in the fetal membranes, birth fluids and vaginal mucus, as well as in the milk and other excretions of several domestic mammals. The finding of C. burnetii in association with abortion, parturition and in the postpartum period has led to the hypothesis that C. burnetii causes a range of reproductive diseases. This review critically evaluates the scientific basis for this hypothesis in domestic mammals.The review demonstrates a solid evidence for the association between C. burnetii infection and sporadic cases of abortion, premature delivery, stillbirth and weak offspring in cattle, sheep and goats. C. burnetii induced in-herd epidemics of this complete expression of reproductive failure have been reported for sheep and goats, but not for cattle. The single entities occur only as part of the complex and not as single events such as generally increased stillbirth rate. Studies show that C. burnetii initially infects the placenta and that subsequent spread to the fetus may occur either haematogenous or by the amniotic-oral route. The consequences for the equine, porcine, canine and feline conceptus remains to the elucidated but that infection of the conceptus may occur is documented for most species. There is no solid evidence to support a hypothesis of C. burnetii causing disorders such as subfertility, endometritis/metritis, or retained fetal membranes in any kind of domestic animal species.There is a strong need to validate non-pathology based methods such as polymerase chain reaction for their use in diagnostic and research in relation to establishing C. burnetii as the cause of abortion and to adapt an appropriate study design and include adequate control animals when linking epidemiological findings to C. burnetii or when evaluating effects of vaccination in production herds.     

A one-year descriptive epidemiology of zoonotic abortifacient pathogen bacteria in farm animals in Turkey

This study aimed to investigate the epidemiology of 10 suspicious pathogenic bacteria in 250 stomach contents of aborted calf, lamb, and goat foetuses in 2019. The 155 positive samples obtained from PCR consisted of 53 (58.88 %) bacteria from 90 lamb samples, 10 (43.47 %) bacteria from 23 goat samples, and 92 (67.15 %) bacteria from 137 calf samples. The five most common bacteria associated with abortions were Brucella melitensis, 52 (20.9 %); B. abortus, 13 (5.2 %); Leptospira spp., 34 (13.6 %); Campylobacter fetus, 52 (20.9 %); and Coxiella burnetii, 4 (1.6 %). The highest rate of B. melitensis (65.4 %), B. abortus (69.2 %), Leptospira spp. (67.6 %), and C. fetus (50 %) was detected in the aborted calf samples. The highest individual rate was that of C. fetus (5.2 %). The flock-herd rates of B. melitensis, B. abortus, Leptospira spp., C. fetus, and C. burnetii infections in the 29 farms studied were 34.48 %, 20.69 %, 62.06 %, 82.75 %, and 3.44 %, respectively, with a confidence level and interval of 95 %. The frequency of abortions caused by Leptospira spp. and Campylobacter fetus may be related to increasing in B. melitensis. The rates of aborted calf, lamb, and goat foetuses among the various sampling periods and regions were significantly (P < 0.01) different. In conclusion, precautions should be applied to reduce the spread of these bacterial agents in high-risk areas and to eliminate the risk of harbouring these zoonotic infections in humans. Therefore, these results must be taken into account in the development of control and protection strategies against abortions in animals.     

Improvement of Leptospira spp. diagnosis in aborted bovine fetuses by qPCR

Leptospirosis is a disease with major economic impact on livestock industry. The objective of this work was to determine the presence of Leptospira spp. DNA by qPCR in bovine fetuses with presumptive diagnosis of leptospirosis as the cause of abortion. Leptospira spp. DNA was detected by qPCR in 11 out of 34 fetuses. These specimens (10/11) had histopathological findings in hepatic and/or renal tissues compatible with leptospirosis. qPCR detection rate (32.4 %) was higher compared with direct immuno-fluorescence antibody test (DFAT) (11.8 %). The concordance coefficient between both techniques was 0.44. qPCR is a rapid and sensitive technique for the diagnosis of leptospirosis and improved the detection rate in fetal tissues compared with DFAT. Implementation of molecular techniques may increase the accurate detection of leptospirosis as a cause of bovine abortion allowing the application of rapid therapeutic and prophylactics measures in order to reduce the impact of this zoonotic disease.     

Molecular detection of <Emphasis Type="Italic">Chlamydophila abortus</Emphasis>, <Emphasis Type="Italic">Coxiella burnetii</Emphasis>, and <Emphasis Type="Italic">Mycoplasma agalactiae</Emphasis> in small ruminants’ aborted fetuses in southern Iran

Abortion in sheep and goats has become increasingly important worldwide because of the significant economic losses and potential zoonotic implication of commonly involved pathogens. Therefore, this cross-sectional study was conducted in southern Iran to detect the Chlamydophila abortus and Coxiella burnetii, as zoonotic pathogens, and Mycoplasma agalactiae, as a neglected abortifacient agent in small ruminants’ aborted fetuses, by using polymerase chain reaction (PCR). From a total of 300 aborted fetuses (183 sheep and 117 goats), 46 samples (15.5%) were positive by PCR, 11% for C. abortus, 2% for C. burnetii, and 3% for M. agalactiae. Also, the association of suggested risk factors with abortion due to these bacterial agents was investigated using univariable and multivariable logistic regression. Results of the statistical analysis showed significant association of C. abortus with flock size (OR?=?2.82, P?=?0.014), season (P?<?0.05), and the number of pregnancy in the aborted dam (OR?=?2.5, P?=?0.05). Our results indicated that C. abortus has a relatively substantial role in small ruminant abortions, and C. burnetii and M. agalactiae are likely important abortifacient agents in our region, too. Regarding veterinary and/or public health importance of these bacterial agents, more attention from veterinary and/or human health services and, maybe, a surveillance system for control and prevention of them are recommended.     

High prevalence and risk factors of Coxiella burnetii in milk of dairy animals with a history of abortion in Iran

Coxiella burnetii is causative agent of Q fever, which is a public health problem in most countries. The aim of this study was to study the prevalence rate of C. burnetii in raw milk of dairy animals in Iran with previous history of abortion. In this survey, milk samples were collected from different dairy animals with history of abortion from Qom province (center of Iran). Samples were tested by Nested PCR and Real-time PCR for detection of IS1111 gene of C. burnetii. In total, 34.92% (44 of 126) milk samples were positive for C. burnetii. Prevalence of C. burnetii in cattle, sheep and goat milk was 33.33%, 35.71% and 35.71%, respectively. Age was a significant risk factor for shedding of C. burnetii in cattle (P = 0.02) and goat (P = 0.05). Shedding of C. burnetii was high prevalence in milk of dairy animals with history of abortion in Iran. The high prevalence of this bacterium in milk (especially in animals with history of abortion) indicates that Excreted by milk as a potential source to spread of infection in the environment.     

Canine leptospirosis—Do we have a problem?

Acute canine leptospirosis is well known to vet surgeons. To protect dogs against this lethal disease, vaccination is widely used. However, chronic forms of leptospirosis have been noticed even in vaccinated animals, generally induced by bacteria from serogroups other than Icterohaemorrhagiae and Canicola such as Sejroë, Australis or Grippotyphosa. In a survey on 98 ill cats, 48% were positive in microagglutination test (MAT) to Leptospira spp., showing that this infection is also frequent in the feline species.     

Pathogenic Leptospira spp. in bats: Molecular investigation in Southern Brazil

The present study aimed to investigate the frequency of pathogenic Leptospira spp. in Brazilian bats and to determine possible risk factors associated to it. Ninety two bats of 12 species were evaluated. Whole genomic DNA from kidneys was extracted and real-time PCR specific to pathogenic Leptospira spp. was applied. Association between the frequency of specimens positive for Leptospira spp. and sex, age, bat species or family, season of collection, geographic localization and feeding habits was evaluated. The results showed that 39.13% of analyzed bats were found positive for Leptospira spp. Nine bat species had at least one positive result. There was no association among the evaluated variables and frequency of pathogenic Leptospira spp. Although the limitations due to lack of Leptospira spp. isolation, leptospiral carriage was demonstrated in bats of different species from southern Brazil, which reinforces the need for surveillance of infectious agents in wild animals.     

Comparison of steroid receptor expression in normal, dysplastic, and neoplastic canine and feline mammary tissues

Steroid receptor expression was assessed by immunohistochemistry in neoplastic, hyperplastic/dysplastic, and normal mammary tissue samples removed from 68 queens and 47 bitches, using monoclonal antibodies against human oestrogen-alpha (ER) and progesterone receptors (PR). Mammary lesions were classified according to World Health Organization (WHO) criteria, and all animals with invasive carcinomas were clinically followed for 2 years. Stromal and/or lymphatic invasion and histological grading were also recorded. In both species, ER expression was significantly higher in healthy tissues, hyperplastic/dysplastic lesions, and benign tumours than in carcinomas. The loss of ER expression was more marked in feline than in canine carcinomas. In queens, PR expression increased in dysplastic lesions and "in situ" carcinomas and decreased in invasive carcinomas, even if parts of these tumours were still PR-positive. In bitches no significant variation in PR expression was observed between normal tissue, dysplasias, and benign neoplasms, but was significantly lower in carcinomas. In both species ER and PR expression in invasive carcinomas did not correlate either with histological parameters or overall survival time. This study demonstrates several differences in steroid hormone dependency between the two species. The percentage of PR-positive feline carcinomas suggests a possible role of progesterone in promoting early tumour cell growth in queens. The low percentage of ER-positive invasive carcinomas further demonstrated the aggressive phenotype and behaviour of feline mammary tumours.     

Prevalence of Coxiella burnetii and Brucella spp. in tissues from subsistence harvested northern fur seals (Callorhinus ursinus) of St. Paul Island,Alaska

Background

The northern fur seal (Callorhinus ursinus) is an important cultural and nutritional resource for the Aleut community on St. Paul Island Alaska. In recent years, an increasing number of zoonotic pathogens have been identified in the population, but the public health significance of these findings is unknown. To determine the prevalence of Coxiella burnetii and Brucella spp. in northern fur seal tissues, eight tissue types from 50 subsistence-harvested fur seals were tested for bacterial DNA by real-time polymerase chain reaction.

Findings

Of the 400 samples tested, only a single splenic sample was positive for Brucella spp. and the cycle threshold (ct) value was extremely high suggesting a low concentration of DNA within the tissue. C. burnetii DNA was not detected.

Conclusions

Findings suggest that the risk of humans contracting brucellosis or Q fever from the consumption of harvested northern fur seals is low.     

Epidemiological Analysis of Leptospira spp. Infection in Equids from the Brejo Paraibano Microregion of Brazil

Leptospirosis is a zoonotic disease that occurs in humans and several animal species, including cattle, pigs, and horses, and it has a worldwide distribution. In equids, leptospirosis manifests through recurrent uveitis and abortion and other reproductive disorders. The objective of the present study was to investigate the epidemiological situation of Leptospira spp. infection in equids from the Brejo Paraibano microregion in the northeast of Brazil, that is, to assess the prevalence of and identify the major risk factors for infection. For this purpose, blood samples were taken from 257 equids (204 horses, 46 mules, and 7 donkeys), and a microscopic agglutination test (MAT) was used as serological analysis, with 24 serovars of Leptospira spp. as antigens. Antibodies were observed in 16.2% of horses, 13.0% of mules, and 28.6% of donkeys. Animals between the ages of 2.5 and 11 years had a risk of infection 0.4 times lower than those younger than 2.5 years old (odds ratio, 0.4; 95% confidence interval, 0.18-0.90). Further studies are needed to identify potential wild reservoirs and the main routes of infections.     

Cross-sectional study on Brucella spp., Leptospira spp. and Salmonella spp. in bats from Montes Claros,Minas Gerais,Brazil

The understanding on the role of bats in the ecology of zoonotic diseases, especially its relevance as a carrier of pathogens, is important for the determination of preventive measures considering the One Health context. The present study aimed to investigate the presence of Brucella spp., Leptospira spp. and Salmonella spp. in blood (n = 163), liver (n = 35) and spleen (n = 62) samples from bats captured in Montes Claros, Minas Gerais, Brazil. Only Salmonella spp. was found in a blood sample of an insectivorous female bat of the species Lasiurus blossevilli, evidencing the capacity of this animal species to host this pathogen. In conclusion, our results in bats from Montes Claros indicate that they do not act as hosts for Brucella spp. and Leptospira spp., although being potential carriers of Salmonella spp. in a low prevalence.     

Molecular detection of Coxiella burnetii and Neospora caninum in equine aborted foetuses and neonates

Abortion, stillbirth and neonatal death are major causes of equine mortality and cause severe economic loss to the equine industry. The present study was based on a complete necropsy protocol associated with classical microbiological examinations and molecular biology on 407 cases of abortion, stillbirths and neonate death. Based on this retrospective survey, "less common" abortive infectious agents were characterised by molecular tools in nine independent cases of abortion or neonate mortality. Among others, Chlamydophila abortus (1 case), Coxiella burnetii (6 cases) and Neospora caninum (3 cases) were detected by real-time PCR; one of these samples being co-infected by N. caninum and C. burnetii. DNA detection of this latter bacterium is reported here for the first time in equine abortion samples. C. burnetii should, along with other common pathogens, probably be taken into account in equine abortion.     

Risk factor analysis for antibodies to Brucella, Leptospira and C. burnetii among cattle in the Adamawa Region of Cameroon: a cross-sectional study

Brucellosis, leptospirosis and Q fever are important livestock diseases, commonly responsible for significant production losses, yet their epidemiology in sub-Saharan Africa is largely unknown. Animal reservoirs pose the main risk of transmission to humans, where serious disease can occur. In the developing world setting, the flu-like symptoms of the acute stages of these diseases can be misdiagnosed as malaria, which can result in the administration of the wrong treatment, prolonged disease and increase in antibiotic resistance. Multivariable mixed-effects logistic regression models in this study revealed potential risk factors associated with the aforementioned pathogens in cattle in the Adamawa Region of Cameroon, with wildlife, namely, buffaloes, playing a major role in both Brucella and Coxiella burnetii seropositivity. Cattle mixing with other herds at night and cattle grazing in an area on a route taken by herds on transhumance appear to be positively associated with Leptospira seropositivity, while female cows and whether buffaloes are seen during grazing or transhumance are positively associated with C. burnetii seropositivity. On the other hand, animals that have been on transhumance in the past year and animals belonging to herdsmen of the Fulbe ethnic group appear to be protected against Leptospira and C. burnetii, respectively. Cattle of more than 2 years old appear to have increased odds of being seropositive to either pathogen. Further research is needed to confirm these findings and improve the knowledge of the epidemiology of these three pathogens in Africa, taking particular consideration of the wildlife involvement in the disease transmission.     

Neosporosis, toxoplasmosis, and sarcocystosis in ruminants.

Neospora caninum, Sarcocystis spp, and Toxoplasma gondii are related coccidian parasites that can cause abortion and neonatal mortality in animals. In addition, T gondii and certain species of Sarcocystis are zoonotic. This article reviews information on the etiology, diagnosis, control, and prevention of these diseases.     

Seroepidemiological study on Coxiella burnetii and associated risk factors in ruminants at Kurdistan Province,west of Iran

Q fever is zoonotic disease caused by Coxiella burnetii. Ruminants are the main reservoir of this pathogen, which is often asymptomatic but lead to abortion. This study aims to survey the seroprevalence and risk factors of this zoonose among ruminants in Kurdistan province, the west of Iran. 480 blood samples were collected from ruminants including sheep, goats and cows, each 160 samples, in the age groups of <1, ≥1−3, >3−5 year with and without the history of abortion in two groups border and non-border cities in Kurdistan province. Serums were tested by use of indirect ELISA to determine specific antibodies against C. burnetii. The results indicate the seroprevalence of 46.6 % for Q fever. Seroprevalence in sheep, goats and cows were 28.58 % (n = 64), 45.53 % (n = 102) and 25.89 % (n = 58), respectively. Seroprevalence is significantly higher in animals with abortion than in those without such history (P < 0.05). The seroprevalence in the border cities has been significantly higher than other geographical areas (P < 0.05). Seroprevalence had no significant correlation with animal age (P> 0.05). This study is the first seroepidemiological study done on Q fever in ruminants of Kurdistan province, Iran. The results indicate the high seroprevalence of Coxiella burnetii in the area under the study. Therefore, doing an epidemiologically study aimed at isolating C. brunetii in the human population of Kurdistan province is recommended, so that the epidemiological aspect of this pathogen in the people of Kurdistan province be clarified and subsequently disease control and prevention programs be applied.     

The role of leptospirosis in reproductive disorders in horses

Leptospirosis is a zoonotic disease of global importance and has a worldwide distribution. This infection displays clear seasonal nature in some regions of the tropics, where the rainy season is marked by high temperatures. Household and wild animals carry leptospires and contribute to their dissemination in nature. Transmission mainly occurs by contact with water contaminated with the urine of infected animals, and consequently, it is quite widespread especially in times of rain, since many areas are subject to flooding and have poor sanitation. Serological tests demonstrate that Leptospira sp. infection in horses occurs worldwide and that the predominant serovar may vary depending on the region or infection sources. Besides systemic and ocular manifestations, leptospirosis in horses has been recognized as an important disease of the reproductive system, since it leads to the birth of weak foals, stillbirths or neonatal mortality, and mainly to abortion, usually after the sixth month of pregnancy. In this context, this review aims to gather and discuss information about the role of leptospirosis in reproductive disorders in horses.     

Molecular detection of Coxiella burnetii in horse sera in Iran

Coxiella burnetii is a zoonotic bacterium that can infect a wide range of animals including horses. However, its circulation dynamics in and through horses are still unclear. The aim of this study was to evaluate prevalence of C. burnetii and its genomic characteristics in horse sera samples in the North of Iran (Golestan Province). The samples were collected in 2018 and the age, sex, and breed of each animal were recorded. Nested-PCR was used to detect C. burnetii based on the presence of the transposable gene IS1111. The results showed that 7.50 % (P < 0.05; 95 % CI: 0.5 %–0.12 %) of the examined sera samples were positive for C. burnetii. Based on the resuls, prevalence of C. burnetii in the age groupof < Years 1–5 (p-value <0.05, 95 % CI: 1 %–8 %) was less than the age group of >6 years old (p-value <0.05, 95 %, CI: 7 %–19.8 %). In previous studies, it was concluded that the horses' population in Golestan Province should be considered as an important factor in the epidemiology of Q fever and consequently in public health. Further studies should be implemented to evaluate if horses may be relevant indicators of zoonotic risk in urban and suburban endemic areas.     

Association between antibodies to Coxiella burnetii in bulk tank milk and perinatal mortality of Danish dairy calves

Background

Coxiella burnetii is a well-known cause of placentitis and subsequent abortion in ruminants, but there are no reports on the relationship with perinatal mortality. The study was performed to determine the influence of level and change of bulk tank milk (BTM) antibodies to C. burnetii on two outcomes associated with parturition in cattle: a) stillbirth; and b) stillbirth and neonatal mortality combined (perinatal death).

Methods

Twenty-four Danish dairy herds were tested repeatedly for antibodies to C. burnetii in BTM using a commercial ELISA. Samples were collected monthly from July 2008 to July 2009. Information on the 2,362 calvings occurring in the study period was obtained from the Danish Cattle Database. Two multilevel logistic regression models were created for the two outcomes stillbirth and perinatal mortality. One model included the level of BTM antibodies in a specified period before or after the outcome had occurred. The other model included the change in antibodies over time. These predictors were included both at herd and animal level. Furthermore, all models included parity and breed.

Results

The individual monthly BTM antibody levels were highly correlated within herds. Consequently, changes in BTM antibody levels were not found to be associated with neither risk of stillbirth nor the risk of perinatal mortality. However, the risk of stillborn calves and perinatal death was higher with high level of BTM antibodies 8 to 9 months after the incident, but not outside this period.

Conclusion

We conclude that the level of antibodies to C. burnetii in BTM may be associated with perinatal mortality, but the association was not persistent and should be investigated further.     

Multidisciplinary approach in the diagnosis of acute leptospirosis in dogs naturally infected by Leptospira interrogans serogroup Icterohaemorrhagiae: A prospective study

Leptospirosis, a zoonotic disease with worldwide distribution, is caused by spirochetes of the genus Leptospira. In dogs, this disease is frequently misdiagnosed. Few studies have attempted to associate the detection of Leptospira spp. infection with clinicopathological and renal histopathological findings using a multidisciplinary approach. The present study isolated and characterized Leptospira spp. obtained from naturally infected dogs and described relevant clinical and histopathological findings. Blood and urine were collected from 57 dogs with clinical symptomatology suggestive of leptospirosis; 38 cases were confirmed by PCR in urine or by culture or microscopic agglutination testing (titers ≥800). A total of 12 strains of pathogenic Leptospira were isolated from the studied dogs (seven in blood, four in urine and one in both blood and urine samples). All isolates were characterized as Leptospira interrogans serogroup Icterohaemorrhagiae. Of the confirmed cases, almost one-third of the animals had been vaccinated. Our analysis of laboratory testing revealed that azotemia and proteinuria were statistically significant predictors of infection. The main histopathological findings seen in kidney tissues were necrosis, degeneration, tubular regeneration, mononuclear inflammatory infiltrate and congestion. A multidisciplinary approach involving clinicopathological and histopathological characterization of renal involvement can aid in the identification of acute leptospirosis infection.     

Detection of bacterial contamination and DNA quantification in stored blood units in 2 veterinary hospital blood banks

Blood transfusions in veterinary medicine have become increasingly more common and are now an integral part of lifesaving and advanced treatment in small and large animals. Important risks associated with transfusion of blood products include the transmission of various infectious diseases. Several guidelines suggest what infectious agents to screen for in canine and feline transfusion medicine. However, while the risk of bacterial contamination of blood products during storage and administration has not been documented in veterinary medicine, it has emerged as a cause of morbidity and mortality in human transfusion medicine. Clinical experience shows that the majority of blood component bacterial contaminations are caused by only a few species. Unlike other types of bacteria, psychrotolerant species like Pseudomonas spp. and Serratia spp. can proliferate during the storage of blood units at 4°C from a very low titer at the time of blood collection to a clinically significant level (> 10⁵ CFU/mL) causing clinical sepsis resulting from red blood cell concentrate transfusions in human medicine. The purpose of this report was to describe the detection and quantification procedures applied in 4 cases of bacterial contamination of canine and feline blood units, which suggest the need for further investigations to optimize patients’ safety in veterinary transfusion medicine.