Clinical and Microbiological Characterization of Bloodstream Infections Caused by Mycoplasma hominis: An Overlooked Pathogen

Abstract

Introduction: Bloodstream infection (BSI) is associated with high mortality rates. Mycoplasma hominis, which rarely causes extragenital infections, has been shown to induce BSI and presents a clinical diagnostic and therapeutic challenge. Methods: In this study, we investigated the clinical characteristics, antibiotic resistance, and multilocus sequence typing (MLST) of eight BSI cases caused by M. hominis in South China from January 2018 to October 2021. Results: Underlying immunosuppression and genitourinary tract surgery are important risk factors for M. hominis BSI. The most prevalent clinical symptoms and signs were fever. Additional findings included elevated neutrophil count and C-reactive protein level. Furthermore, in this study, all the patients had erythrocytopenia. M. hominis harbored the highest rate of resistance to levofloxacin (75.0%), followed by sparfloxacin (50.0%), and gatifloxacin (37.5%). gyrA S153L was the most frequent mutation in levofloxacin-resistant strains, followed by parC S91I. parC K144R may be related to resistance to gatifloxacin and sparfloxacin. Eight strains showed sensitivity to all the other antibiotics analyzed (doxycycline, minocycline, josamycin, and clindamycin). MLST was performed in seven isolates, and seven new sequence types were described. We compared our isolates with all M. hominis strains from the PubMLST database, and one major clonal complex and eight singletons were identified. Conclusions: Our study clarified and expanded the clinical features and antibiotic resistance of M. hominis BSI. These findings are useful for the clinical diagnosis and control of M. hominis BSI.

Case Report: Double trouble: a rare case of successfully treated Mycoplasma hominis and Pseudomonas aeruginosa co-infection

“…In this report, the patient was co-infected with M. hominis and P. aeruginosa , which manifested as fever and an increase of PCT and lactic acid. These clinical manifestations are in accordance with the reported typical symptoms of M. hominis bloodstream infection ( Zeng et al., 2022 ). P. aeruginosa blood infection was successfully treated with short-term antibiotics therapy.…”

“…Mycoplasma hominis ( M. hominis ) commonly colonizes the genitourinary tract in a nonvirulent manner ( Whitson et al., 2014 ). Nevertheless, it is an opportunistic pathogen that can cause a variety of genitourinary or extragenital infections, as well as neonatal infections ( Poku, 2022 ; Zeng et al., 2022 ). However, this pathogen is commonly underestimated and overlooked in clinical settings due to undetermined pathogenic processes ( Ahmed et al., 2021 ).…”

“…For instance, to date, only five cases of M. hominis were isolated from the blood over a 10-year period, as reported by the Public Health England reference laboratory ( Chalker et al., 2021 ). Even in China, with the largest population, M. hominis was only detected in eight (0.7%) of 1,148 patients with bloodstream infection ( Zeng et al., 2022 ). Due to the limited knowledge on M. hominis bacteremia, its clinical features, diagnosis, drug resistance, and treatment recommendations have not yet been fully established.…”

Application of Next-Generation Sequencing on Diagnosis of Bloodstream Infection Caused by Mycoplasma hominis in a Patient With ANCA-Associated Vasculitis

“…M.hominis is naturally resistant to all β-lactams because of the lack of a cell wall. Two antibiotic families, tetracyclines and fluoroquinolones showed strong action against these bacteria [22,23]. More than 80% of M. hominis isolates were resistant to erythromycin, roxithromycin, azithromycin and clarithromycin.…”