Emergence of multidrug-resistant Pandoraea sputorum in Japan

Pandoraea is a pathogenic bacterium naturally resistant to various antimicrobials, including colistin. Here, we report the whole-genome sequence of Pandoraea sputorum, which exhibits high-level multidrug resistance, isolated from a hospitalized patient in Japan.

Detecting and characterizing new endofungal bacteria in new hosts: Pandoraea sputorum and Mycetohabitans endofungorum in Rhizopus arrhizus

The fungus Rhizopus arrhizus (=R. oryzae) is commonly saprotrophic, exhibiting a nature of decomposing organic matter. Additionally, it serves as a crucial starter in food fermentation and can act as a pathogen causing mucormycosis in humans and animals. In this study, two distinct endofungal bacteria (EFBs), associated with individual strains of R. arrhizus, were identified using live/dead staining, fluorescence in situ hybridization, transmission electron microscopy, and 16S rDNA sequencing. The roles of these bacteria were elucidated through antibiotic treatment, pure cultivation, and comparative genomics. The bacterial endosymbionts, Pandoraea sputorum EFB03792 and Mycetohabitans endofungorum EFB03829, were purified from the host fungal strains R. arrhizus XY03792 and XY03829, respectively. Notably, this study marks the first report of Pandoraea as an EFB genus. Compared to its free-living counterparts, P. sputorum EFB03792 exhibited 28 specific virulence factor-related genes, six specific CE10 family genes, and 74 genes associated with type III secretion system (T3SS), emphasizing its pivotal role in invasion and colonization. Furthermore, this study introduces R. arrhizus as a new host for EFB M. endofungorum, with EFB contributing to host sporulation. Despite a visibly reduced genome, M. endofungorum EFB03829 displayed a substantial number of virulence factor-related genes, CE10 family genes, T3SS genes, mobile elements, and significant gene rearrangement. While EFBs have been previously identified in R. arrhizus, their toxin-producing potential in food fermentation has not been explored until this study. The discovery of these two new EFBs highlights their potential for toxin production within R. arrhizus, laying the groundwork for identifying suitable R. arrhizus strains for fermentation processes.

Hepato and nephroprotective activity of methanol extract of Hygrophila spinosa and its antibacterial potential against multidrug resistant Pandoraea sputorum

This research was aimed to evaluate the phytochemical profile, bactericidal activity of Hygrophila spinosa against multidrug resistant Pandoraea sputorum and assess their antioxidant competence against various radicals and studied their hepatoprotective and nephroprotective activity on HepG2 and HEK 293 cell line. The results showed that the methanol extract has various phytochemical components with reasonable quantity. Fortunately, the multidrug-resistant P. sputorum was sensitive (22.8 ± 0.2 mm of the zone of inhibition) at 15 mg mL^-1 concentration of methanol extract. The higher concentration of phenolic and other phytochemical components, showed significant antioxidant activity against ferric, DPPH, hydroxyl, and ABTS radicals, with IC₅₀ values of 71.09, 64.333, 91.157, and 104.931 g mL^-1, respectively. Surprisingly, the methanol extract possesses hepato and nephroprotective activity against CCl₄ and cisplatin-induced cytotoxicity on HepG2 and HEK 293 cell lines, respectively. It maintains the cell viability as up to 90.48% and 90.35% of HepG2 and EK 293 cell line at the concentration of 20 μg mL^-1. The FTIR analysis states that the methanol extract possesses a significant functional group responsible for these multi-potential activities. These results suggest that, the methanol extract of H. spinosa might contain the most significant bioactive components with outstanding medicinal properties.

Pandoraea sputorum Bacteremia In A Patient Who Had Undergone Allogeneic Liver Transplantation Plus Immunosuppressive Therapy: A Case Report

Pandoraea sputorum (P. sputorum), an emerging pathogen, is able to trigger a pronounced pro-inflammatory response that results in lung dysfunction in cystic fibrosis (CF) patients. All previous P. sputorum isolates have been obtained from the respiratory samples of CF patients, with no reported cases of P. sputorum bacteremia. For the first time, we report P. sputorum isolates recovered twice from the blood cultures of a patient with liver cancer who had undergone allogeneic liver transplantation. These isolates were successfully identified by combining mass spectrometry and molecular techniques based on 16S rRNA sequencing methods. At the onset of the P. sputorum bacteremia, the patient’s peripheral T, B and NK cell counts were 181.68/μL, 59.57/μL and 70.66/μL, respectively. The serum procalcitonin level, C-reactive protein level and peripheral neutrophil granulocyte percentage were 0.56 ng/mL, 61.00 mg/L and 96.8%, respectively. We found these isolates to be susceptible to ciprofloxacin and piperacillin/tazobactam and to be intermediate to amikacin. Previous studies have found P. sputorum isolates to be resistant. All of the data combined showed that compromised immune function from allogeneic liver transplantation plus immunosuppressive therapy contributes to the occurrence of P. sputorum bacteremia. Furthermore, the P. sputorum isolates demonstrated characteristic resistance profiles.

First time identification of Pandoraea sputorum from a patient with cystic fibrosis in Argentina: a case report

Background

Pandoraea species are considered emerging pathogens in the context of cystic fibrosis (CF) and are difficult to identify by conventional biochemical methods. These multidrug resistant bacteria remain poorly understood particularly in terms of natural resistance, mechanisms of acquired resistance and impact on the prognosis of the disease and the lung function. Among them, Pandoraea sputorum has been previously described in few cases of CF patients from Spain, Australia, France and United States, underlining the need of more clinical data for a better knowledge of its pathogenicity. This is the first report relating to P. sputorum in a CF patient in Argentina.

Case presentation

Pandoraea sputorum was identified in a nine-year-old cystic fibrosis patient from Argentina, after treatment failure during an exacerbation. The isolates were successfully identified by combining molecular techniques based on 16S rRNA sequencing and mass spectrometry (MS) methods, after reassessing previous misidentified isolates by conventional methods. After first isolation of P. sputorum, patient’s clinical condition worsened but later improved after a change in the treatment. Although isolates showed susceptibility to trimethoprim–sulfamethoxazole and imipenem, in our case, the antibiotic treatment failed in the eradication of P. sputorum.

Conclusions

All combined data showed a chronic colonization with P. sputorum associated to a deterioration of lung function. We noted that the presence of P. sputorum can be underestimated in CF patients and MALDI-TOF MS appears to be a promising means of accurate identification of Pandoraea species.