Search Results (6)

Gonococcal and chlamydial conjunctivitis and keratoconjunctivitis are potentially sight-threatening ocular manifestations of sexually transmitted infections. Recent epidemiological data indicate rising rates of gonorrhoea and chlamydia infections worldwide, raising concerns about a possible increase in associated ocular infections. This retrospective single-center study analyzed the frequency and temporal trends of laboratory-confirmed gonococcal and chlamydial ocular infections in adults treated at the University Hospital Zurich between January 2005 and July 2025. Clinical characteristics, treatment, complications, and outcomes were additionally assessed for gonococcal cases. We identified 17 gonococcal and 121 chlamydial conjunctivitis or keratoconjunctivitis cases over the past approximately 20.5 years. A marked increase in gonococcal cases was observed between 2021 and 2025 (p < 0.0001), during which 70.6% of all cases were diagnosed. Complications occurred in 41.1% of gonococcal infections, including one corneal perforation requiring keratoplasty. Although gonococcal conjunctivitis and keratoconjunctivitis remain rare, their recent increase and risk of severe ocular complications highlight the importance of early recognition and prompt treatment. In contrast, chlamydial conjunctivitis was more common, affected a younger population, and showed a significant declining trend, with an average annual decrease of 5% (p = 0.0015). Full article

A herd of approximately 300 Spanish meat goats in central Alabama experienced sporadic ocular, respiratory, and reproductive diseases over two years, prompting diagnostic investigation at Auburn University’s JT Vaughan Large Animal Teaching Hospital. Five representative doelings exhibiting ocular lesions were examined. Clinical signs included conjunctivitis, corneal opacity, uveitis, and, in one severe case, systemic illness. Initial treatment with topical and systemic antibiotics provided incomplete resolution, raising suspicion of infectious keratoconjunctivitis of atypical etiology. Comprehensive diagnostic testing was performed, including aerobic and Mycoplasma cultures, Giemsa staining, and molecular assays. Moraxella bovoculi was cultured; however, Giemsa staining revealed Chlamydia elementary bodies, and a FRET-qPCR with DNA sequencing confirmed high Chlamydia pecorum loads (up to 1.1 × 10⁷ copies/swab). Mycoplasma testing was negative. Extended treatment with systemic and topical oxytetracycline led to gradual clinical improvement, with C. pecorum DNA declining over 22,000-fold and becoming undetectable after five weeks. This case represents the first documented report of C. pecorum–associated keratoconjunctivitis in goats in the United States. The findings underscore the diagnostic importance of molecular assays for detecting intracellular pathogens that may be missed by culture. The protracted treatment course highlights the therapeutic challenges posed by chlamydial infections due to their intracellular persistence. Additionally, the concurrent detection of M. bovoculi suggests the potential for mixed infections influencing disease severity. These results emphasize C. pecorum as an emerging pathogen of caprine ocular disease with implications for herd health and management. Full article

Chlamydia trachomatis is an evasive pathogen that can prompt severe clinical manifestations in humans such as vaginitis, epididymitis, lymphogranuloma venereum, trachoma, conjunctivitis and pneumonia. If left untreated, chronic infections with C. trachomatis can give rise to long-lasting and even permanent sequelae. To shed some light on its widespread nature, data from original research, systematic reviews and meta-analyses from three databases was collected and analyzed in the context of chlamydial infection, related symptoms and appropriate treatment modalities. This review describes the bacterium’s pervasiveness on a global scale, especially in developing countries, and suggests ways to halt its transmission and spread. Infections with C. trachomatis often go unnoticed, as many individuals are asymptomatic and unaware of their diagnosis, contributing to a delay in diagnosis and treatment. The high prevalence of chlamydial infection highlights the need for a universal screening and detection method enabling immediate treatment at its onset. Prognosis is favorable with antibiotic therapy and education for high-risk groups and their sexual partners. In the future, a quick, easily accessible, and inexpensive test should be developed to diagnose and treat infected individuals early on. Along with a vaccine against C. trachomatis, it would halt the transmission and spread of the pathogen worldwide. Full article

Chlamydia (C.) suis can often be isolated from conjunctival swab specimens from pigs with conjunctivitis or keratoconjunctivitis. In the field, it is assumed to be a multifactorial disease triggered by immunosuppressing factors. This is the first experimental study to provoke clinical signs of conjunctivitis in pigs after C. suis primary mono-infection. Five six-week-old male piglets, free of ocular chlamydia shedding and seronegative for Chlamydia, were conjunctivally infected with the C. suis-type strain S45 (1 × 10⁹ inclusion forming units), while four piglets served as negative controls. The infection group developed clinical signs of conjunctivitis with a peak in the first week post-infection. Immunohistochemical evaluation revealed the presence of Chlamydia not only in the conjunctival epithelium, but also in the enlarged lacrimal glands, lungs, and intestine. No circulating antibodies could be detected during the whole study period of three weeks, although three different test systems were applied as follows: the complement fixation test, MOMP-based Chlamydiaceae ELISA, and PmpC-based C. suis ELISA. Meanwhile, high numbers of IFN-γ-producing lymphocytes within PBMC were seen after C. suis re-stimulation 14 days post-infection. Hence, these data suggest that entry via the eye may not elicit immunological responses comparable to other routes of chlamydial infections. Full article

Chlamydia suis (C. suis) resides in the intestines of pigs and tetracycline-resistant strains are emerging worldwide. Intestinal infections are often subclinical. However, the gut is regarded as a C. suis reservoir and clinical infections have been associated with enteritis, conjunctivitis, pneumonia and reproductive failure. C. suis was found in boar semen and venereal transmission occurred. We studied the anti-Chlamydia suis activity of ovotransferrin (ovoTF) and bovine lactoferrin (bLF). Pre-incubation of C. suis with bLF or ovoTF had no significant effect on overall chlamydia replication (mean fluorescence area) in McCoy cells. The addition of ovoTF to the culture medium had no effect on bacterial replication, but the addition of 0.5 or 5 mg/mL of bLF significantly reduced the inclusion size by 17% and 15% respectively. Egg components are used for cryopreservation of boar semen. When inoculating an ovoTF-containing and Chlamydia suis-spiked semen sample in McCoy cells, a significant reduction in inclusion number (by 7%) and overall replication (by 11%) was observed. Thus, we showed that transferrins possess anti-chlamydial activity. Moreover, ovoTF addition to semen extenders might reduce C. suis venereal transmission. Further research is needed to unravel the mechanisms behind the observations and to enhance the effect of transferrins on C. suis. Full article

Vaccines can have heterologous effects on the immune system, i.e., effects other than triggering an immune response against the disease targeted by the vaccine. We investigated whether monoclonal antibodies (mAbs) specific for tetanus could cross-react with Chlamydia and confer heterologous protection against chlamydial infection. The capability of two tetanus-specific mAbs, namely mAb26 and mAb51, to prevent chlamydial infection has been assessed: (i) in vitro, by performing a neutralization assay using human conjunctival epithelial (HCjE) cells infected with Chlamydia trachomatis serovar B, and (ii) in vivo, by using a guinea pig model of Chlamydiacaviae-induced inclusion conjunctivitis. The mAb26 has been superior in comparison with mAb51 in the prevention of chlamydial infection in HCjE cells. The mAb26 has conferred ≈40% inhibition of the infection, compared to less than 5% inhibition in the presence of the mAb51. In vivo, mAb26 significantly diminished ocular pathology intensity in guinea pigs infected with C. caviae compared to either the mAb51-treated or sham-treated guinea pigs. Our data provide insights that tetanus immunization generates antibodies which induce heterologous chlamydial immunity and promote protection beyond the intended target pathogen. Full article