Skin and Mucous Membrane Eruptions Associated with Chlamydophila Pneumoniae Respiratory Infections: Literature Review

The Chlamydia pneumoniae inclusion membrane protein Cpn0308 interacts with host protein ACBD3

Chlamydia pneumoniae is an obligate intracellular bacterium of eukaryotic cells characterized by a unique biphasic life cycle; its biosynthesis and replication must occur within a cytoplasmic vacuole or inclusion. Certain inclusion membrane proteins have been demonstrated to mediate the interactions between intra-inclusion chlamydial organisms and the host cell. It has been demonstrated previously that the C. pneumoniae-encoded Cpn0308 localizes to the inclusion membrane; however, its function remains unknown. In the current study, a yeast two-hybrid assay was conducted to screen Cpn0308 as a bait against a HeLa cell cDNA library, revealing its binding to the host protein acyl-coenzyme A binding domain-containing 3 (ACBD3). The interaction between Cpn0308 and ACBD3 was confirmed through co-immunoprecipitation and GST (Glutathione S-transferase) pull-down assays. The two proteins were also co-localized in HeLa cells co-expressing Cpn0308 and ACBD3, as well as in C. pneumoniae-infected cells, as observed under confocal fluorescence microscopy. Given that ACBD3 plays a crucial role in maintaining host cell lipid homeostasis and its Golgi dynamic domain is responsible for interacting with Cpn0308, we hypothesize that the Cpn0308-ACBD3 interaction may facilitate C. pneumoniae's acquisition of host lipids, thereby benefiting chlamydial survival. This study lays a foundation for further elucidating the mechanisms of Cpn0308-mediated C. pneumoniae pathogenesis.IMPORTANCEThe biosynthesis and replication of Chlamydia pneumoniae (Cpn) must occur within the cytoplasmic vacuoles or inclusions of host cells. Inclusion bodies play a crucial role in mediating the interactions between Cpn and host cells. Cpn0308 is localized to the inclusion membrane; however, its function is unknown. In this study, Cpn0308 was found to bind to host protein acyl-coenzyme A binding domain-containing 3 (ACBD3) through some standard approaches. Co-localization of the two proteins was observed in both original HeLa cells and Cpn-infected HeLa cells. ACBD3 plays a significant role in maintaining lipid homeostasis in host cells; we speculate that the Cpn0308-ACBD3 interaction may facilitate the acquisition of host lipids by C. pneumoniae, thereby enhancing chlamydial survival.

Epidemiological Study on Mycoplasma pneumoniae and Chlamydia pneumoniae Infection of Hospitalized Children in a Single Center During the COVID-19 Pandemic

Background

Since the outbreak of COVID-19, a series of preventive and control measures in China have been used to effectively curb the spread of COVID-19. This study aimed to analyze the epidemiological characteristics of Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP) in hospitalized children with acute respiratory tract infection during the COVID-19 pandemic.

Methods

MP IgM antibody and CP IgM antibody were detected in all hospitalized children due to acute respiratory tract infection in the Children’s Hospital Affiliated to Zhejiang University from January 2019 to December 2020. These data were compared between 2019 and 2020 based on age and month.

Results

The overall detection rate of MP and CP in 2020 was significantly lower than that in 2019 (MP: 21.5% vs 32.9%, P<0.001; CP: 0.3% vs 0.9%, P<0.001). This study found a 4-fold reduction in the number of children positive for MP and a 7.5-fold reduction in the number of children positive for CP from 2019 to 2020. The positive cases were concentrated in children aged >1 year old. In 2019, the positive rate of MP was detected more commonly in children 3 years of age or older than in younger children. In 2020, the higher positive rate of MP reached a peak in the 3- to 6-year age group (35.3%). CP was detected predominantly in children aged 6 years older in 2019 and 2020, with positive rates of 4.8% and 2.6%, respectively. Meanwhile, the positive rates of MP in 2019 were detected more commonly in July, August and September, with 47.2%, 46.7% and 46.3%, respectively. Nevertheless, the positive rates of MP from February to December 2020 apparently decreased compared to those in 2019. The positive rates of CP were evenly distributed throughout the year, with 0.5%-1.6% in 2019 and 0.0%-2.1% in 2020.

Conclusions

A series of preventive and control measures for SARS-CoV-2 during the COVID-19 pandemic can not only contain the spread of SARS-CoV-2 but also sharply improve the infection of other atypical pathogens, including MP and CP.

Immunoglobulin A vasculitis induced by atypical pneumonia infection with Chlamydophila pneumonia

Infections are a common trigger for IgA vasculitis. Among the bacteria that cause atypical pneumonia, Mycoplasma pneumoniae infection has strongly been associated with IgA vasculitis, with Chlamydophila pneumoniae reported with IgA vasculitis in only one case. Though IgA vasculitis is a self-limiting disease, patients with infection-related vasculitis have shown to benefit from early identification and treatment with antimicrobial therapy. Here, we report a case of IgA vasculitis due to C. pneumoniae infection in a 19-year-old male who presented with an acute onset of rash, that was later followed by symptoms of cough and fever.

Mucosal Respiratory Syndrome: A Systematic Literature Review

BACKGROUND

Mycoplasma pneumoniae atypical pneumonia is frequently associated with erythema multiforme. Occasionally, a mycoplasma infection does not trigger any cutaneous but exclusively mucosal lesions. The term mucosal respiratory syndrome is employed to denote the latter condition. Available reviews do not address the possible association of mucosal respiratory syndrome with further atypical bacterial pathogens such as Chlamydophila pneumoniae, Chlamydophila psittaci, Coxiella burnetii, Francisella tularensis, or Legionella species. We therefore performed a systematic review of the literature addressing this issue in the National Library of Medicine, Excerpta Medica, and Web of Science databases.

SUMMARY

We found 63 patients (≤18 years, n = 36; >18 years, n = 27; 54 males and 9 females) affected by a mucosal respiratory syndrome. Fifty-three cases were temporally associated with a M. pneumoniae and 5 with a C. pneumoniae infection. No cases temporally associated with C. psittaci, C. burnetii, F. tularensis, or Legionella species infection were found. Two cases were temporally associated with Epstein-Barr virus or influenzavirus B, respectively.