Tigecycline in the treatment of severe pneumonia caused by Chlamydia psittaci: A case report and literature review

Abstract

Psittacosis is a zoonotic disease caused by Chlamydia psittaci. Systemic infections are mainly transmitted through the respiratory tract. The most common related disease is human atypical pneumonia, which is a rare pathogen of community-acquired pneumonia. Due to the difficulty of diagnosis, there have been few reports of C. psittaci pneumonia in the past. In recent years, with the widespread application of metagenomic next-generation sequencing (mNGS), the number of reported cases of C. psittaci has increased year by year. However, at present, most hospitals have little understanding of C. psittaci, especially for severe patients, and lack experience in diagnosis and treatment. Herein, we report the case of a 71-year-old woman with severe pneumonia that caused by C. psittaci. This patient was diagnosed through mNGS and was treated with tigecycline successfully. The level of IL-6 in the BALF was significantly increased. We discontinued tigecycline after mNGS of the blood was negative. In this review, we analyzed 53 cases to summarize the etiology, clinical manifestations, diagnosis and treatment strategies of severe C. psittaci pneumonia and hope to raise clinicians’ awareness of this disease.

Effect of Growth Stage on Nutrition, Fermentation Quality, and Microbial Community of Semidry Silage from Forage Soybean

“…In addition, by comparing the flora structure before and after silage, we also observed the decline and death of some low-abundance pathogenic bacteria. For example, Pseudomonas can cause bacteremia and urinary tract infections in animals or humans [ 35 ]; Klebsiella can cause pneumonia, hysteritis, mastitis, and other suppurative inflammation in animals [ 36 ]; and Flavobacterium can cause pneumonia, meningitis, septicemia, and other diseases [ 37 ]. The number of these bacteria decreased significantly after silage.…”

Treatment of Chlamydial Infections

“…Serological testing is primarily utilized in retrospective research and is not very useful for the earlier detection of severe patients. C. psittaci is easily identified by NAAT and metagenomic nextgeneration sequencing; however, these procedures are not routinely utilized in most hospitals [104]. Therefore, a patient with a history of bird contact who exhibits atypical pneumonia symptoms or unexplained fever without localizing signs, clinicians should consider a diagnosis of psittacosis, and treatment should not await a definitive diagnosis.…”

“…Beta-lactam antibiotics are not effective in psittacosis, whereas tetracyclines and macrolides are both effective against C. psittaci. Tetracyclines and especially doxycycline is the preferred medication for the treatment of C. psittaci pneumoniae [104,105].…”

“…Also, a 5 to 7-day regimen of azithromycin (if a clinical response is observed) can be used alternatively. The third-line antibiotics for C. psittaci are fluoroquinolones, which have less potency than tetracyclines and macrolides [95,104,107]. With proper and early treatment overall prognosis is good and death occurs in less than 1% of patients [102,104].…”

Research progress of mNGS in the diagnosis and treatment of chlamydia psittaci pneumonia

“…At present, the traditional detection methods of chlamydia psittaci mainly include the following: pathogen isolation and identification, immunofluorescence, indirect hemagglutination inhibition test, complement binding test, ELISA, conventional (polymerase chain reaction) PCR and fluorescent PCR (polymerase chain reaction) [13]. Specific diagnostic criteria are as follows: (1) Chlamydia psittaci was isolated and cultured from respiratory secretions [14]; (2) The titer of Chlamydia psittaci specific IgG antibody was increased by 4 times or more in the double serum at the acute stage and the recovery stage; (3) Chlamydia psittaci DNA was detected positive by PCR.…”