Enzootic Abortion.

Chlamydia abortus is a zoonotic pathogen that causes miscarriage, stillbirth, and sepsis of pregnancy in pregnant women when it infects humans. However, it rarely causes pneumonia in humans. This case reports a case of severe pneumonia characterized by high fever and cough, and the disease rapidly progressed to dyspnea. The patient was treated with moxifloxacin and doxycycline. Chlamydia abortus was detected in bronchoscopy examination and bronchoalveolar lavage fluid (BALF) through metagenomic next-generation sequencing (mNGS)-DNA. A weak positive for influenza A (H1N1) antigen was also found in the throat swab tested. Subsequently, we added mabaloxavir and replaced doxycycline with an intravenous infusion of omadacycline. After effective treatment, the patient developed a urinary tract infection, and the treatment plan was adjusted to meropenem combined with omadacycline. The patient's condition improved, and she was discharged on the 14th day of admission. This is the first report of cases of non-pregnant female patients with Chlamydia abortus infection pneumonia. Consequently, infections with Chlamydia abortus can result in severe respiratory distress, disturbance of water and electrolyte balance, and abnormal liver function, which requires timely diagnosis and correct use of antibiotics by clinicians. Consequently, the mixed infection of H1N1 and Chlamydia abortus aggravated the complexity of the condition and treatment. Combining tetracycline and quinolone is effective for treating severe pneumonia with Chlamydia abortus infection.

Brucella spp., Toxoplasma gondii, and Chlamydia abortus have long been recognized as zoonoses and significant causes of reproductive failure in small ruminants globally. A cross-sectional study was conducted in August 2020 to determine the seroprevalences of Brucella spp., Toxoplasma gondii and Chlamydia abortus in 398 small ruminants from four districts of Zimbabwe (Chivi, Makoni, Zvimba, and Goromonzi) using Indirect-ELISAs. A structured questionnaire was used to assess the knowledge, attitudes, and practices of 103 smallholder farmers towards small ruminant abortions, Brucella spp., T. gondii and C. abortus, and to obtain a general overview of the significance of small ruminant reproductive failure(s) on their livelihoods. The overall seroprevalences were: 9.1% (95% CI: 6.4-12.3) for Brucella spp., 6.8% (95% CI: 4.5-9.7) for T. gondii and 2.0% (95% CI: 0.9-3.9) for C. abortus. Location, age, parity, and abortion history were associated with Brucella spp. seropositivity. Location was also associated with both T. gondii and C. abortus seropositivity. The questionnaire survey established that 44% of respondents had recently faced reproductive disease challenges within their flocks, with 34% correctly identifying abortion causes and only 10%, 6% and 4% having specific knowledge of Brucella spp., C. abortus and T. gondii, respectively. This study provides the first serological evidence of Brucella spp. in small ruminants since 1996 and builds the evidence on small ruminant toxoplasmosis and chlamydiosis in Zimbabwe. Evidence of these zoonoses in small ruminants and the paucity of knowledge shows the need for a coordinated One Health approach to increase public awareness of these diseases, and to establish effective surveillance and control measures. Further studies are required to establish the role these diseases play in small ruminant reproductive failure(s), to identify the Brucella spp. detected here to species/subspecies level, and to assess the socio-economic impact of reproductive failure in livestock among marginalised rural communities.

After the first case of Schmallenberg virus (SBV) was reported in southern Spain (March 2012), a retrospective serological study was carried out in extensive sheep flocks from nearby areas to assess the history of exposure to SBV and other selected ovine reproductive pathogens (Chlamydophila abortus, Coxiella burnetii, Border Disease virus 'BDV', Toxoplasma gondii and Neospora caninum). Secondly, the presence of antibodies was investigated in meat juice samples against selected pathogens to validate their use in serosurveys in sheep. A total of 209 Merina and cross-bred culled ewes belonging to 12 outdoor flocks managed in extensive breeding systems were sampled. Serum and meat juice samples were collected at the slaughterhouse and analysed using commercial ELISA kits. Chlamydophila abortus (62.68%, CI95 56.13-69.23) and Toxoplasma gondii (57.42%, CI95 50.72-64.12) were the most prevalent pathogens. The seroprevalence of BDV (16.27%, CI95 11.27-21.27) and Coxiella burnetii (13.88%, CI95 9.2-18.56) was moderate, and only 4 of 209 animals (1.91%, CI95 1.82-2.96) presented specific antibodies against Neospora caninum or SBV. All the examined ovine flocks were seropositive to three or more pathogens. The highest percentage of seropositive animals was detected for T.gondii-C.abortus coseropositive (25.36%) culled ewes. The concordance between serum and meat juice samples was moderate for T.gondii (κ=0.419) and BDV (κ=0.568), and fair for C.abortus (κ=0.311). Our results show evidence of circulation of SBV from summer 2011 in southern Spain. Furthermore, C.abortus and T.gondii were the most prevalent pathogens associated with sheep in outdoor rearing systems. Finally, these preliminary results point to meat juice samples as a potential biological sample for serosurveys studies on sheep.

Comparative evaluation of a new commercial recombinant ELISA and the complement fixation test for the diagnosis of Chlamydophila abortus infection in naturally infected flocks in Tunisia

Chlamydophila abortus is the causative agent of abortion in pigs and pregnant women. Seroconversion rates were arranged from 11% to 80% in piglets and sows in China. These very high rates illustrate the scale of the problem in China and highlight the urgent need for the development of a C. abortus vaccine. An efficacious anti-chlamydial vaccine should induce not only strong mucosal and systemic T-helper type 1 (Th1) immune response but also give a humoral response that enhances Th1 activation following infection. In order to evaluate an active immune response of a combination of the major outer membrane protein (MOMP) DNA- and protein-based vaccines, 54 BALB/c mice were randomly assigned to six groups and inoculated intramuscularly with: (i) 100 microg pcDNA::MOMP, (ii) 10 microg r-MOMP, (iii) primed with 100 microg pcDNA::MOMP and boosted with 10 microg r-MOMP, (iv) primed-boosted with a combination of pcDNA::MOMP and r-MOMP simultaneously, (v) live-attenuated 1B vaccine, (vi) 100 microg pcDNA3.1 vector. All animals were vaccinated two times at 14 days intervals. Results showed that mice given DNA and r-MOMP induced higher antibody levels, higher T cells proliferation and an elevated level of chlamydial clearance in spleen, which was equivalent to the clearance of 1B vaccine. Mice administrated the DNA-primed/MOMP-boosted approach elicited moderate antibody levels, less T-lymphocyte proliferation and lower chlamydial clearance as compared with 1B vaccine. Co-immunization with DNA- and r-MOMP vaccine may provide novel ways for active immunization strategy against swine C. abortus.

On a farm housing cattle and goats an abortion storm occurred affecting 50% of the goats during the lambing season 2000/2001. In one of three investigated caprine abortions Chlamydophila abortus could be identified as aetiology. During this time a pregnant woman (pregnancy week 19/20) had contact with aborting goats. She developed a severe generalized infection and aborted. The placenta contained Chlamydophila abortus shown by immunohistochemistry and PCR. The aim of the present case report is to alert medical doctors about the potential zoonotic risk of ovine/caprine abortions.

Infectious keratoconjunctivitis (IKC) is a highly contagious ocular inflammatory condition, which is often reported in domestic small and large ruminants. Multiple infectious aetiologies are reported to be involved, but information about the role of certain fastidious bacterial pathogens such as chlamydiae and mycoplasmas is limited in India. Hence, this study was performed to determine the role of these pathogens and their identification by molecular approach. A total of 53 samples from 31 ovine, 14 caprine and eight bovine having clinical symptoms were collected and tested using species-specific PCR tests for chlamydiae and mycoplasmas followed by nucleotide sequence analysis. The results showed 77.41, 14.29 and 25% samples were chlamydiae positive in ovine, caprine and bovine, respectively, whereas 41.93, 14.29 and 37.5% prevalence of mycoplasma infection was detected in ovine, caprine and bovines, respectively. Chlamydophila abortus, Chlamydophila psittaci, Mycoplasma arginini and Mycoplasma hyorhinis were detected from tested samples. To the best of our knowledge, this is the first time these species are identified in IKC cases from India. Coinfection of both chlamydial and mycoplasmal species was detected in eight IKC cases of ovine which suggest synergistic roles played by both chlamydiae and mycoplasma in IKC samples.

Abortion cases of 144 goats und 86 sheep were investigated etiologically during 2 lambing seasons (1996/1997, 1997/1998). Macroscopic inspection of fetus and placenta was completed by histopathology and bacteriological isolation of agents. In addition, immunohistologically the following antigens were labeled in formalin-fixed and paraffin-embedded tissue sections: Toxoplasma gondii, Neospora caninum, Chlamydophila abortus (formerly Chlamydia psittaci serovar 1) and Border Disease Virus. From farms with abortions caused by Chlamydophila abortus specific data were recorded. In 75% of abortion cases in sheep and in 59% of cases in goats an etiologic diagnosis could be substantiated. Chlamydophila abortus is the most commonly involved agent in the etiology of caprine and ovine abortion (sheep 39%, goats 23%), followed by Toxoplasma gondii (sheep 19%, goats 15%) and Coxiella burnetti (sheep 1%, goats 10%). All other agents are of minor importance. An infectious cause of abortion based on histopathologic findings without isolation of agents was observed in sheep (10%) and goats (21%). Malformation occurred in sheep (2%) and goats (3%) and lesions suggestive for Vitamin E/Selenium deficiency were seen in goats only (2%).

Chlamydia abortus is a zoonotic abortifacient bacterium causing a large variety of diseases with detrimental economic impact, mainly in ruminants. A total of 345 cows belonging to 42 herds were randomly sampled to conduct a cross sectional study, aiming to establish the seroprevalence of this pathogen (using iELISA test) and its associated risk factors (through a questionnaire) in dairy cattle from Oum-El-Bouaghi and Setif provinces (Northeastern Algerian high plateaus). All over the studied zone, specific chlamydial antibodies were detectable in 58 cows (16.8%) belonging to 13 infected herds (30.9%). The individual animal seroprevalence ranged from 12.6% (18/143) to 19.8% (40/202) in Oum-El-Bouaghi and Setif respectively and the herd one varied from 30% (06/20) to 31.8% (07/22) as well. At the herd level, none of the tested factors had an effect on chlamydial antibodies prevalence; while at the individual animal level, associations (univariately evaluated with p<0.05) were recorded for herd size, deficient disinfection and origin of cows and feed. Multivariable logistic regression analysis revealed origin of cows to be protective and history of infertility as potential risk factor in Setif only. These results are clear evidences that C. abortus is endemic in our dairy cattle population, in which it plays some role in their decreased reproductive performances.

BackgroundChlamydia abortus, as a pathogen of atypical pneumonia, is rare in humans, especially in HIV infection patients.Case presentationWe present the case of a 48-year-old man with a history of HIV infection who started high fever and developed pneumonia. The pathogen-targeted next-generation sequencing (ptNGS) results of bronchial lavage fluid showed Chlamydia abortus infection.ConclusionThis is the first report of Chlamydia abortus infection presented as atypical pneumonia in an AIDS patient.

Intratracheal infection as an efficient route for testing vaccines against Chlamydia abortus in sheep

Мета статті – надати актуальну на сьогоднішній день таксономічну класифікацію порядку Chlamydiales та детально роз’яснити терміни: «Chlamydia-related bacteria (CRB)» (хламідіє-споріднені бактерії,) «Chlamydia-like organisms (CLO)» (хламідіє-подібні організми), «environmental chlamydiae» (екологічні хламідії, хламідії довкілля). Методика дослідження. Використано такі методи дослідження: системний аналіз доступних наукових джерел, історичний метод (для вивчення виникнення, формування та розвитку таксономії хламідійних видів у хронологічній послідовності), емпіричний метод (щодо комплексної оцінки сучасного стану об’єкта дослідження), абстрактно-логічний ‒ для уточнення суті основних понять та графічне відображення даних. Результати дослідження. Внаслідок розвитку молекулярної біології за останні 15 років класифікація хламідій зазнала істотних змін і має тенденцію до подальшого вдосконалення. У статті узагальнено історичний досвід і найбільш важливі зміни в таксономії порядку Chlamydiales за останні роки. Ускладнення сучасної класифікації бактерій порядку Chlamydiales свідчить про накопичені знання щодо нових представників цієї групи мікроорганізмів. На сьогодні до порядку Chlamydiales входять 9 родин: Chlamydiaceae, Waddliaceae, Parachlamydiaceae, Criblamydiaceae, Simkaniaceae, Candidatus Clavochlamydiaceae, Candidatus Rhabdochlamydiaceae, Candidatus Piscichlamydia, Candidatus Parilichlamydiaceae, чотири з яких перебувають у статусі кандидатів. До родини Chlamydiaceae, роду Chlamydia тепер належать 14 видів бактерій (Chlamydia abortus, Chlamydia avium, Chlamydia caviae, Chlamydia felis, Chlamydia gallinacea, Chlamydia muridarum, Chlamydia pecorum, Chlamydia pneumoniae, Chlamydia psittaci, Chlamydia suis, Chlamydia trachomatis, Candidatus Chlamydia ibidis, Candidatus Chlamydia sanzinia, Candidatus Chlamydia corallus), три з яких перебувають у статусі кандидатів. Родини: Waddliaceae, Parachlamydiaceae, Criblamydiaceae, Simkaniaceae, Ca. Clavochlamydiaceae, Ca. Rhabdochlamydiaceae, Ca. Piscichlamydia, Ca. Parilichlamydiaceae з їхніми численними представниками називають хламідіє-спорідненими бактеріями, або хламідіє-подібними організмами, через їх генетичну і фенотипову подібність та філогенетичну відокремленість від родини Chlamydiaceae. Елементи наукової новизни. У цій статті представлено актуальну таксономічну класифікацію порядку Chlamydiales та надано детально роз’яснено терміни: «Chlamydia-related bacteria (CRB)» (хламідіє-спорідненені бактерії,) «Chlamydia-like organisms (CLO)» (хламідіє-подібні організми), «environmental chlamydiae» (екологічні хламідії, хламідії довкілля). Практична значущість. Надана інформація може бути використана в наукових дослідженнях, впроваджена в навчальний процес при підготовці спеціалістів у галузі ветеринарної медицини, а також використовуватися практикуючими лікарями ветеринарної медицини задля покращення лікування та профілактики хламідіозів тварин та людини. The purpose of the article is to provide the currently relevant taxonomic classification of the Order Chlamydiales, and give a detailed explanation of the terms: “Chlamydia-related bacteria (CRB)”, “Chlamydia-like organisms (CLO)”, "Environmental chlamydiae" (ecological chlamidiae). Research methods. The following research methods were used: system analysis of the available scientific sources, historical method (to study the origin, formation and development of the taxonomy of chlamydia species in chronological order), empirical method (concerning the comlex assessment of the current state of the research object), abstract-logical – to clarify the essence of the basic notions and graphical reflection of the data. The results of the study. As a result of molecular biology development during the recent 15 years, the classification of chlamydia has undergone significant changes and has the tendency to further improvement. This review article is aimed at summarizing the historical experience and the most important changes in the taxonomy of the Order Chlamydiales in recent years. The complication of the modern classification of the Order Chlamydiales bacteria is the inevitable consequence of accumulating knowledge about the new representatives of this group of microorganisms. Consequently at present there are 9 families in the Order Chlamydiales: Chlamydiaceae, Waddliaceae, Parachlamydiaceae, Criblamydiaceae, Simkaniaceae, Candidatus Clavochlamydiaceae, Candidatus Rhabdochlamydiaceae, Candidatus Piscichlamydia, Candidatus Parilichlamydiaceae, four of them are in the status of candidates. Currently, 14 species of bacteria belong to the family Chlamydiaceae, the genus Chlamydia (Chlamydia abortus, Chlamydia avium, Chlamydia caviae, Chlamydia felis, Chlamydia gallinacea, Chlamydia muridarum, Chlamydia pecorum, Chlamydia pneumoniae, Chlamydia psittaci, Chlamydia suis, Chlamydia trachomatis, Candidatus Chlamydia ibidis, Candidatus Chlamydia sanzinia, Candidatus Chlamydia corallus), three of which are the candidates. Such families as: Waddliaceae, Parachlamydiaceae, Criblamydiaceae, Simkaniaceae, Ca. Clavochlamydiaceae, Ca. Rhabdochlamydiaceae, Ca. Piscichlamydia, Ca. Parilichlamydiaceae with their numerous representatives are called Сhlamydia-related bacteria, or Сhlamydia-like organisms, due to their genetic and phenotypic similarity, and phylogenetic isolation from the Chlamydiaceae family. The elements of scientific novelty. The currently relevant taxonomic classification of Chlamydiales is presented in the article and also given a detailed explanation of the terms: “Chlamydia-related bacteria (CRB)”, “Chlamydia-like organisms (CLO)”, "Environmental chlamydiae". Practical significance. The provided information can be used in scientific research, introduced into the educational process for training specialists of veterinary medicine, and also be used by practicing veterinary doctors in order to improve the treatment and prevention of animals and human chlamydioses.

Although the seroprevalence of Toxoplasma gondii, Neospora caninum, Chlamydia abortus and bovine viral diarrhea virus infection in cattle have been reported in some areas in China, most of them were conducted with small number of cattle samples and very limited districts and neglected the assessment of herd management factors associated with herd-level prevalence of these pathogen infections. Thus, from September 2013 to December 2014, a large-scale seroprevalence study was conducted to determine the animal-level and herd-level seroprevalence and identify herd-level risk factors associated with these pathogen infections in 4487 cattle from 134 herds in five provinces (Heilongjiang, Jilin, Liaoning, Shandong, Hebei) and Inner Mongolia Autonomous Region of China. At animal level, the true prevalence of antibodies against T. gondii, N. caninum, C. abortus and bovine viral diarrhoea virus (BVDV) was 10.48, 17.14, 11.92 and 50.10%, respectively. At herd level, the true prevalence of antibodies against T. gondii, N. caninum, C. abortus and BVDV was 27.16, 29.10, 37.31 and 40.30%, respectively. Multivariate analysis of these characteristics showed that source of water and presence of felids were significantly associated with T. gondii infection in the studied cattle herds. Source of water was significantly associated with N. caninum infection in the studied cattle herds. While herd size and management system were significantly associated with BVDV infection in the studied cattle herds, this is the first report of herd-level prevalence and associated risk factors of T. gondii, N. caninum, C. abortus and BVDV infection in cattle in China.

BackgroundPneumonia infected by Chlamydia abortus (C. abortus) is rare, especially complicated with severe acute respiratory distress syndrome (ARDS) and multiple organ dysfunction syndrome (MODS).Case PresentationWe presented the clinical details of a 44-year-old male who was diagnosed with C. abortus pneumonia, which rapidly progressed and ultimately led to ARDS, sepsis and MODS. Although he was initially diagnosed with pneumonia upon admission, no pathogenic bacteria were detected in sputum by conventional tests. Empirical intravenous infusion of meropenem and moxifloxacin was administered, but unfortunately, his condition deteriorated rapidly, especially respiratory status. On Day 2 after extracorporeal membrane oxygenation (ECMO) initiation, metagenomic next-generation sequencing (mNGS) was performed on the patient’s bronchoalveolar lavage fluid, which indicated an infection with C. abortus. The patient’s antimicrobial therapy was adjusted to oral doxycycline (0.1g every 12h), intravenous azithromycin (0.5g every day), and imipenem and cilastatin sodium (1g every 6h). The patient’s condition improved clinically and biologically. However, the patient was discharged due to financial reasons and unfortunately passed away eight hours later.ConclusionInfections with C. abortus can result in severe ARDS and serious visceral complications which necessitate prompt diagnosis and active intervention by clinicians. The case highlights the significance of mNGS as an essential diagnostic tool for uncommon pathogens. Tetracyclines, macrolides or their combinations are effective choices for treatment of C. abortus pneumonia. Further study is needed to explore the transmission routes of C. abortus pneumonia and establish precise guidelines for antibiotic treatment.

Relationship between the immune response and protection conferred by new designed inactivated vaccines against ovine enzootic abortion in a mouse model