Cellulitis and Bacteremia due to Corynebacterium striatum Identified by Matrix-assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry

Infective endocarditis and septic arthritis caused by Corynebacteriumstriatum

Corynebacterium striatum occasionally causes nosocomial infections, such as catheter-related bloodstream infection and pneumonia; however, C. striatum-related infective endocarditis or septic arthritis is uncommon. We present the case of an 85-year-old woman with infective endocarditis at the native valve and septic arthritis at the native shoulder joint caused by C. striatum. The patient was admitted for a 10-day history of fever and right shoulder pain. She had no history of artificial device implantation, injury, arthrocentesis, or hospitalization. A physical examination revealed conjunctival petechiae, a systolic heart murmur, and right shoulder joint swelling. C. striatum was observed in two blood culture sets. Transesophageal echocardiography revealed vegetation in the right aortic coronary cusp. Arthrocentesis at the right shoulder aspirated pyogenic fluid and C. striatum was detected in the culture. The patient was diagnosed with infective endocarditis and septic arthritis caused by C. striatum, and ampicillin was administered based on antimicrobial susceptibility test results. The patient's condition was initially stable; however, she developed pulmonary congestion on day 56 and eventually died. An autopsy demonstrated perforation of the aortic left coronary cusp with vegetation. C. striatum may cause native valve endocarditis and native joint septic arthritis.

Corynebacterium striatum Bacteremia during SARS-CoV2 Infection: Case Report, Literature Review, and Clinical Considerations

Bacterial infections, especially those in hospital settings, represent a major complication of COVID-19 patients, complicating management and worsening clinical outcomes. Corynebacterium striatum is a non-diphtheric actinobacterium that has been reported as being the causative agent of several different infections, affecting both immunocompetent and immunocompromised patients. Recently, C. striatum has been recognized as a nosocomial pathogen that is responsible for severe infection in critical patients, as well as in fragile and immunocompromised subjects. C. striatum has been described as the etiological agent of bacteremia, central line infections, and endocarditis. We report a case of a 91-year-old woman who was hospitalized due to SARS-CoV-2 infection, who developed C. striatum bacteremia and died despite antimicrobial therapy and clinical efforts. Furthermore, we discuss C. striatum diagnosis and treatment based on evidence from the scientific literature.

Intestinal Flora: A Potential Mechanism by Which Yinlai Decoction Treats Lipopolysaccharide-Induced Pneumonia

Background. We intended to explore the mechanism of Yinlai decoction in the treatment of lipopolysaccharide (LPS)-induced pneumonia from the perspective of intestinal flora. Methods. Thirty Sprague–Dawley rats were randomly assigned to the blank control group (N), the pneumonia group (P), and the Yinlai decoction group (PT). The rat pneumonia model was established using LPS inhalation (0.5 mg/mL, 5 mL, 30 min/day, 3 days). Yinlai decoction was administered intragastrically (2 mL/100 g, 3 days). Lung tissue pathology, organ indexes, serum inflammatory factors, tumor necrosis factor-alpha (TNF-α), and intestinal flora changes were measured. Results. Lung tissue inflammation was prevented by Yinlai decoction. IL-6 levels showed a higher tendency to be higher, and IL-12 and TNF-α were significantly higher in the PT group than in the P group. The structure of the intestinal flora in the P differed from that in the N. The relative abundance of 10 out of 12 microflora was significantly higher in the P group than in the N and PT groups. In the PT group, the structure and the distribution of microbial groups were like those of the N group. Conclusions. Yinlai decoction inhibited LPS-induced lung and systemic inflammation in rats and may help the intestinal flora restore equilibrium by inhibiting the colonization of pathogenic bacteria and adjusting the ratio between probiotics and pathogenic bacteria. Intestinal flora may serve as a mediator of Yinlai decoction’s effect on LPS-induced pneumonia.

Antimicrobial treatment of Corynebacterium striatum invasive infections: a systematic review

The aim of this study was to establish an evidence-based guideline for the antibiotic treatment of Corynebacterium striatum infections. Several electronic databases were systematically searched for clinical trials, observational studies or individual cases on patients of any age and gender with systemic inflammatory response syndrome, harboring C. striatum isolated from body fluids or tissues in which it is not normally present. C. striatum had to be identified as the only causative agent of the invasive infection, and its isolation from blood, body fluids or tissues had to be confirmed by one of the more advanced diagnostic methods (biochemical methods, mass spectrometry and/or gene sequencing). This systematic review included 42 studies that analyzed 85 individual cases with various invasive infections caused by C. striatum. More than one isolate of C. striatum exhibited 100% susceptibility to vancomycin, linezolid, teicoplanin, piperacillin-tazobactam, amoxicillin-clavulanate and cefuroxime. On the other hand, some strains of this bacterium showed a high degree of resistance to fluoroquinolones, to the majority majority of β-lactams, aminoglycosides, macrolides, lincosamides and cotrimoxazole. Despite the antibiotic treatment, fatal outcomes were reported in almost 20% of the patients included in this study. Gene sequencing methods should be the gold standard for the identification of C. striatum, while MALDI-TOF and the Vitek system can be used as alternative methods. Vancomycin should be used as the antibiotic of choice for the treatment of C. striatum infections, in monotherapy or in combination with piperacillin-tazobactam. Alternatively, linezolid, teicoplanin or daptomycin may be used in severe infections, while amoxicillin-clavulanate may be used to treat mild infections caused by C. striatum.

The composition of microbial aerosols, PM2.5, and PM10 in a duck house in Shandong province, China

Poultry-emitted air pollutants, including microbial aerosols and particulate matter, have raised concerns due to their potential negative effects on human health and the environment. High concentrations of microbial aerosols can also significantly affect duck production performance, leading to immunosuppression and increased disease susceptibility. We determined the concentrations, distributions, and biological components of the microbial aerosols and particulate matter in a duck house environment. The concentration ranges of the bacteria, fungi, Gram-negative bacteria, Escherichia coli, and endotoxin in the duck houses were 3.3 to 5.2 × 104 CFU/m3, 3.8 to 11.9 × 103 CFU/m3, 2.1 to 3.6 × 103 CFU/m3, 1.3 to 2.7 × 102 CFU/m3, and 0.65 to 2.2 × 103 EU/m3, respectively. We also found the endotoxin levels were higher than the standard that can cause pneumonia (2,000 EU/m3). The concentration ranges of the PM2.5 and PM10 samples were 1.1 to 1.6 × 102 μg/m3 and 1.2 to 1.9 × 102 μg/m3, respectively. At the phylum level, the top 5 bacteria identified in the PM2.5 fraction were Actinobacteria, Firmicutes, Proteobacteria, Bacteroidetes, and Fusobacteria, with Actinobacteria (50.55%) as the most abundant. At the genus level, 293 bacterial groups were identified. Actinobacteria (39.01%) was the most abundant phylum, followed by Firmicutes (5.44%) and Proteobacteria (4.56%). The bacterial distributions that differed between the PM2.5 and PM10 samples were Lactobacillales, Bacilli, Firmicutes, and Bacteroidetes; the fungi that differed were Microbotryomycetes, Sporidiobolales, Agaricomycetes, and Polyporates. Microbial allergens and pathogens were also identified. Corynebacterium had a relative abundance of more than 30% in the PM2.5 and PM10 distributions. Aspergillus was the main fungal allergen and opportunistic pathogen, with a relative abundance of 10%. In conclusion, our research supports that the microbial composition in the duck house environment poses a potential threat to the health of both the ducks and the duck house workers.

Genomics of Corynebacterium striatum, an emerging multidrug-resistant pathogen of immunocompromised patients

OBJECTIVES

Corynebacterium striatum is an emerging multidrug-resistant (MDR) pathogen of immunocompromised and chronically ill patients. The objective of these studies was to provide a detailed genomic analysis of disease-causing C. striatum and determine the genomic drivers of resistance and resistance-gene transmission.

METHODS

A multi-institutional and prospective pathogen genomics programme flagged seven MDR C. striatum infections occurring close in time, and specifically in immunocompromised patients with underlying respiratory diseases. Whole genome sequencing was used to identify clonal relationships among strains, genetic causes of antimicrobial resistance, and their mobilization capacity. Matrix-assisted linear desorption/ionization-time-of-flight analyses of sequenced isolates provided curated content to improve rapid clinical identification in subsequent cases.

RESULTS

Epidemiological and genomic analyses identified a related cluster of three out of seven C. striatum among lung transplant patients who had common procedures and exposures at an outlying institution. Genomic analyses further elucidated drivers of the MDR phenotypes, including resistance genes mobilized by IS3504 and ISCg9a-like insertion sequences. Seven mobilizable resistance genes were localized to a common chromosomal region bounded by unpaired insertion sequences, suggesting that a single recombination event could spread resistance to aminoglycosides, macrolides, lincosamides and tetracyclines to naive strains.

CONCLUSION

In-depth genomic studies of MDR C. striatum reveal its capacity for clonal spread within and across healthcare institutions and identify novel vectors that can mobilize multiple forms of drug resistance, further complicating efforts to treat infections in immunocompromised populations.