Pulmonary infection with Penicillium citrinum in a patient with multiple myeloma

Case report: Rare pulmonary fungal infection caused by Penicillium digitatum: the first clinical report in China

Penicillium digitatum is a common plant pathogen that causes citrus rot, which is extremely rare in humans. We report a case of a 66-year-old man with a history of consuming large amounts of citrus fruits, smoking for 30 years, and a history of emphysema. He had experienced intermittent coughing with sputum for more than 10 years and was admitted to the hospital due to worsening of symptoms over the past month. Despite antibiotic treatment, his condition did not improve. Subsequently, bronchoalveolar lavage fluid (BALF) was detected by metagenomic next-generation sequencing (mNGS), which showed the presence of P. digitatum. The fungal culture of BALF also indicated the presence of the Penicillium genus. The diagnosis was lung infection caused by P. digitatum, and the patient was treated with itraconazole. The lung infection was controlled. This is the third reported case of invasive pulmonary fungal infection caused by P. digitatum worldwide at the genus level, and the first reported case in China. Although human infections caused by P. digitatum are rare, as an emerging opportunistic pathogen, the detection of this fungus in immunocompromised patients should still be clinically important.

Severe pneumonia with pleural effusion caused by co-infection of Paecilomyces variotii and Penicillium oxalicum in a diabetic patient

BACKGROUND PAECILOMYCES: and Penicillium are considered as rare opportunistic pathogens in immunocompromised hosts, and pneumonia caused by Paecilomyces and Penicillium is rare. In this study, we present first case of severe pneumonia with pleural effusion caused by co-infection of Paecilomyces variotii (P. variotii) and Penicillium oxalicum (P. oxalicum) in a 66-year-old female with poorly controlled type 2 diabetes. CASE PRESENTATION: A 56-year-old woman patient presented to hospital for nausea, poor appetite, and vomiting for one day. On the second day of admission, blood culture and renal puncture fluid culture grew multidrug-resistant Escherichia coli (imipenem/cilastatin sensitive), and she received combination therapy with imipenem/cilastatin (1 g, every 8 h) and vancomycin (0.5 g, every 12 h). On the fourth day, she developed symptoms of respiratory failure. Pulmonary computed tomography (CT) showed an increase in pneumonia compared to before, with minor pleural effusion on both sides. Two fungi were isolated repeatedly from BALF culture, which were confirmed as P. variotii and P. oxalicum by Internal transcribed spacer (ITS) sequencing. Her pleural effusion was completely absorbed, pneumonia symptoms have significantly improved and discharged with receiving liposomal amphotericin B treatment for four weeks. CONCLUSIONS: It is worth noting that clinicians and laboratory personnel should not simply consider Paecilomyces and Penicillium species as contaminants, especially in immunocompromised patients. Early fungal identification and antifungal drug sensitivity are crucial for clinical drug selection and patient prognosis.

Occupational exposure to inhalable pathogenic microorganisms in waste sorting

This study assessed microorganisms in personal inhalable work air samples aiming to identify potential human pathogens, and correlate exposure to adverse health outcomes in waste workers. Full-shift personal exposure was measured in six different waste sorting plants. Microbial concentrations in inhalable air samples were analysed using MALDI-TOF MS for cultivable, and next generation sequencing (NGS) for non-cultivable microorganisms. Concentrations of bacterial and fungal CFUs varied substantially within and between waste sorting plants, ranging from no identifiable organisms to a maximum concentration in the order of 105 CFU/m3. Bacillus and Staphylococcus were among the most abundant bacterial genera, whilst fungal genera were dominated by Aspergillus and Penicillium. Approximately 15% of all identified species were human pathogens classified in risk group 2, whereas 7% belonged to risk group 1. Furthermore, significant correlations between concentrations of fungi in risk group 1 and self-reported adverse symptoms, such as wheezing were identified in exposed workers. The combination of culture-based methods and NGS facilitated the investigation of infectious microbial species with potential pathophysiological properties as well as non-infectious biological agents in inhalable work air samples and thereby contributed to the risk assessment of occupational exposure in waste sorting.

Molecular characterization of a novel non-segmented double-stranded RNA mycovirus isolated from Penicillium citrinum strain RCEF7060

Penicillium citrinum is a commonly occurring filamentous fungus with a worldwide distribution. However, no sequence data for viruses in P. citrinum have been reported. Here, we characterized a novel dsRNA virus from the hospital indoor air fungal strain P. citrinum RCEF 7060, which we have named "Penicillium citrinum non-segmented dsRNA virus 1" (PcNRV1). The genome of PcNRV1 dsRNA is 2,895 bp in length and contains two open reading frames encoding a protein with an unknown function in ORF1 and a putative RNA-dependent RNA polymerase (RdRp) in ORF2. Sequence comparisons and phylogenetic analysis showed that PcNRV formed a well-supported independent clade together with members of the proposed genus "Unirnavirus" and was most closely related to Penicillium miczynskii RNA virus 1 (PmRV1), with 76.45% amino acid sequence identity in the RdRp. Thus, PcNRV1 is a novel non-segmented dsRNA mycovirus belonging to the proposed genus "Unirnavirus" and is the first characterized viral sequence from P. citrinum.

Inconsistency analysis between metagenomic next-generation sequencing results of cerebrospinal fluid and clinical diagnosis with suspected central nervous system infection

Background

Recently, with the rapid progress of metagenomic next-generation sequencing (mNGS), inconsistency between mNGS results and clinical diagnoses has become more common. There is currently no reasonable explanation for this, and the interpretation of mNGS reports still needs to be standardised.

Methods

A retrospective analysis was conducted on 47 inpatients with suspected central nervous system (CNS) infections, and clinical data were recorded. The final diagnosis was determined by an expert group based on the patient’s clinical manifestation, laboratory examination, and response to treatment. mNGS results were compared with the final diagnosis, and any inconsistencies that occurred were investigated. Finally, the credibility of mNGS results was evaluated using the integral approach, which consists of three parts: typical clinical features, positive results with the traditional method, and cerebrospinal fluid cells ≥ 100 (× 10⁶/L) or protein ≥ 500 mg/L, with one point for each item.

Results

Forty-one patients with suspected CNS infection were assigned to infected (ID, 31/41, 75.61%) and non-infected groups (NID, 10/41, 24.39%) after assessment by a panel of experts according to the composite diagnostic criteria. For mNGS-positive results, 20 of the 24 pathogens were regarded as contaminants when the final score was ≤ 1. The remaining 11 pathogens detected by mNGS were all true positives, which was consistent with the clinical diagnosis when the score was ≥ 2. For mNGS negative results, when the score was ≥ 2, the likelihood of infection may be greater than when the score is ≤ 1.

Conclusion

The integral method is effective for evaluating mNGS results. Regardless of whether the mNGS result was positive or negative, the possibility of infection was greater when the score was ≥ 2. A negative mNGS result does not necessarily indicate that the patient was not clinically infected, and, therefore, clinical features are more important.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07729-0.