Serological Investigation of Bovine Chlamydia abortus in Wasit Province, Iraq

Chlamydia abortus is one of the most common infectious and zoonotic bacteria, which causes abortion in different ruminants as well as other animals and humans. For the first time in Iraq, the current study aimed to identify the prevalence of C. abortus in cattle using the enzyme-linked immunosorbent assay (ELISA). A total of 276 venous blood samples were collected from November (2021) to January (2022), subjected to obtaining sera that ELISA tested. Infection severity and estimation of the relationship between serum positivity and risk factors (including age, sex and region) were evaluated. An overall 17.03% of samples were being positive for C. abortus, which classified as mild (63.83%), moderate (25.53%) and severe (10.64%) infections with OD values of 0.32710.0085, 0.5270.0139 and 0.70840.0256, respectively. The association of positivity to risk factors revealed that there was significant variation in their values as follows: for age, significant increases in prevalence and risk factors were detected in cattle aged <3 years when compared to 3-6 and >6 years; whereas, for sex, significant increases were found in females more than males. For the region, significant higher and lower prevalence and risk exposure to were reported in Al-Hai and Al-Kut, respectively. The association of mild, moderate and severe infections to risk factors showed that moderate infection was elevated significantly in cattle of <3 years, while the mild infection increased significantly in cattle aged 3-6 and >6 years with the absence of severe infection in both last age groups. In females and males and all study regions, mild infection appeared more significantly than moderate and severe infections (P<0.05). The present study was the first serological detection of C. abortus in cattle in Wasit province (Iraq); furthermore, studies are necessary to estimate the prevalence of C. abortus in cattle and other field animals.

Prevalence and factors associated with a higher or lower risk of exposure to Coxiella burnetii, Chlamydia abortus and Toxoplasma gondii in dairy cows that have aborted in Algeria

In Algeria, the prevalence of causes of abortion on dairy cattle farms (whether infectious causes or not) has been little studied. The current study involved a serological analysis conducted between October 2014 and June 2016 in northern Algeria using an enzyme-linked immunosorbent assay test on blood samples taken from 368 cows that had aborted on 124 farms. It was complemented by a survey to identify the factors associated with a higher or lower risk of exposure to Coxiella burnetii, Chlamydia abortus and Toxoplasma gondii, using univariate logistic regression and then multivariate logistic regression. The individual serological prevalences obtained were 8.4% (31/368) for C. burnetii and 12.2% (45/368) for C. abortus. For T. gondii, the individual seroprevalence was 13.8% (51/368); the factors associated with a higher risk of individual exposure were the fourth month of gestation (odds ratio [OR] = 22.68; 95% confidence interval [CI]: 1.38-392.97) and the fifth month of gestation (OR = 25.51; 95% CI: 1.47-442.11). All the other factors identified by the multivariate logistic regression were associated with a lower risk of exposure. They are the inspection visits in 2015 (OR = 0.0006; 95% CI: 0.000004-0.12) and in 2016 (OR = 0.0005; 95% CI: 0.000002-0.13) and artificial insemination (OR = 0.15; 95% CI: 0.05-0.44) for C. burnetii ; winter (OR = 0.39; 95% CI: 0.15-1.00), spring (OR = 0.45; 95% CI: 0.20-0.97), and artificial insemination (OR = 0.27; 95% CI: 0.13-0.56) for C. abortus; and the number of gestations (OR = 0.38; 95% CI: 0.16-0.92) for T. gondii. The seroprevalence at herd level was 16.1% (20/124) for C. burnetii and 29.8% (37/124) for both C. abortus and T. gondii. At herd level, the risk factors associated with a higher risk of exposure to C. abortus and T. gondii were the practice of deworming (OR = 3.89; 95% CI: 1.53-9.89) and drilling individual wells as a source of drinking water (OR = 7.50; 95% CI: 2.11-26.69). For C. burnetii, the inspection visit in 2015 (OR = 0.02; 95% CI: 0.0008-0.65) and in 2016 (OR = 0.01; 95% CI: 0.0003-0.36), artificial insemination (OR = 0.21; 95% CI: 0.06-0.69) and rodent eradication (OR = 0.19; 95% CI: 0.06-0.57) were factors that reduced the risk of exposure.

Improving sensitivity of single tube nested PCR to detect fastidious microorganisms

Single Tube Nested PCR (ST-nPCR) is of value to clinical laboratories with limited settings for the detection of fastidious microorganisms. The detection sensitivity of ST-nPCR is dependent on ensuring minimal leftovers of outer primers during the second round of the reaction. In this work, we investigated various approaches to optimize the performance of outer primers, including decreasing outer primer concentrations; using antisense oligonucleotides to block outer primers; using chemically modified inner primers; and using Q5 Taq polymerase that lacks 5′-3′ exonuclease and strand displacement capabilities. These solutions were tested on C. abortus and C. psittaci, which are both fastidious intracellular bacteria that are difficult to diagnose.

The best obtained result was by using Q5 Taq polymerase. A detection limit with a range between 0.1 and 1 ag was achieved, which corresponds to a range between 0.2 and 2 copies of the plasmid positive control. This level of sensitivity is comparable or even better than the sensitivity achieved by TaqMan probe based real-time PCR assays. The assay was validated using 70 veterinary clinical samples from small ruminant abortions and 10% of these samples gave positive results.

In conclusion, sensitivity of ST-nPCR to detect fastidious microorganisms can be improved by using Taq polymerases that lacks 5′-3′ exonuclease. The proposed assay is affordable and applicable to a wide range of fastidious pathogens and can be suitable for laboratories with limited settings.

A Study on Mycoplasma agalactiae and Chlamydophila abortus in Aborted Ovine Fetuses in Sistan and Baluchestan region, Iran

Abortion is one of the most important economic issues in sheep flocks. Chlamydophila abortus is an agent of enzootic abortions in sheep. Mycoplasma agalactiae is the main etiological agent of contagious agalactia, which can cause abortion in sheep. The aim of this study was to investigate the prevalence of M. agalactiae and C. abortus among aborted ovine fetuses in Sistan and Baluchestan, Iran. Sheep owners were asked to transfer their aborted fetuses to a nearby veterinary clinic; furthermore, they were taught biosecurity principles. A total of 78 aborted sheep fetuses were collected from all over Sistan region in the autumn of 2015 and winter of 2016. The samples were then transferred in ice to the Anatomy Laboratory of the Veterinary Faculty of Zabol University, Zabol, Iran. The spleen and abomasum contents of the fetuses were sampled under sterile and safe conditions. Polymerase chain reaction was used to detect M. agalactiae and C. abortus. The results showed that 24 (30.8%) cases were infected with M. agalactiae. However, infection with C. abortus was not detected in any fetuses. There was no statistically significant relationship between such independent variables as the location of livestock, history of abortion, fetal gender and age, age and parity of ewe, and fetal infection with M. agalactiae. The high incidence of Mycoplasma contamination in this study may be due to inappropriate biosecurity measures and lack of vaccination against agalactia in sheep herds in Sistan region.

Molecular detection of Chlamydophila abortus, Coxiella burnetii, and Mycoplasma agalactiae 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.

Pathogens of zoonotic and biological importance in roe deer (Capreolus capreolus): Seroprevalence in an agro-system population in France

Antibody prevalence for several infectious and parasitic diseases in a population of roe deer (Capreolus capreolus) inhabiting a mixed agricultural landscape (south of France) has been analyzed. Serological analyses with ELISA in 245 animals captured from 2008 to 2012 has been performed. We found a high prevalence of Toxoplasma gondii (46.4%), Chlamydophila abortus (17.27%) and Coxiella burnetii (11.26%) compared to other studies in Europe. Seroprevalence varied strongly among years for T. gondii (27-91%), C. abortus (0-42%) and C. burnetii (0-27%). T. gondii prevalence was lower in juvenile females, compared to juvenile males and adults of both sexes. Other pathogens had low prevalences: Neospora caninum (1.56%), Bovine herpesvirus 1 (1.17%, 2008/09; 1.1%, 2010/11), Mycoplasma agalactiae (1.45%, 2009/10), Mycobacterium avium subsp. paratuberculosis (0.9%) and Slow viruses (CAEV-MVV) (0.15%, 2008/10; 0%, 2011/12). Antibodies to bluetongue virus and pestiviruses were not found in any individual.