Cardiac device-related endocarditis caused by Paenibacillus glucanolyticus

Uncommon Septic Arthritis of the Hip Joint in an Immunocompetent Adult Patient Due to Bacillus pumilus and Paenibacillus barengoltzii Managed with Long-Term Treatment with Linezolid: A Case Report and Short Literature Review

The Bacillus and Paenibacillus genera are diverse soil-related bacterial pathogens. In this case report, we describe, to our knowledge, the first report of septic arthritis in a native hip joint in an immunocompetent adult patient caused by Bacillus pumilus and Paenibacillus barengoltzii. We describe the case of a 39-year-old Caucasian male patient who sought medical advice for chronic pain on the mobilization of the right hip, decreased range of motion, and physical asthenia. The patient underwent a surgical intervention (core decompression) for a right osteonecrosis of the femoral head, with a slightly favorable postoperative evolution after surgery for one month. Surgical treatment was planned on the basis of clinical and paraclinical investigations and the joint damage. The hip was explored using an anterior approach under spinal anesthesia and standard antibiotic prophylaxis. After resection of the femoral head, meticulous debridement of all inflammatory tissues was performed, and a preformed temporary spacer was inserted into the femoral canal. Bacteriological laboratory studies identified Bacillus pumilus and Paenibacillus barengoltzii via matrix-assisted laser desorption-ionization time-of-flight mass spectrometry analysis. The patient initially received nine days of empirical therapy with intravenous antibiotics (linezolid and meropenem). After the bacterial strains were identified, the patient received organism-specific antibiotic therapy with the same antibiotics and dose for eight days until discharge. After discharge, the patient was referred to another hospital, where he continued treatment with linezolid for seven weeks and, after that, four weeks of oral therapy with cotrimoxazole and rifampicin. During this period, no severe or potentially life-threatening adverse events were recorded during long-term treatment with linezolid or with the two oral antibiotics. In conclusion, our findings suggest that long-term treatment with linezolid may be a viable option for the management of bone and joint infections caused by Bacillus pumilus and Paenibacillus barengoltzii.

Infective endocarditis caused by Paenibacillus thiaminolyticus: a case report and review of literature

Background

Paenibacillus constitutes a genus of gram-positive, facultatively anaerobic, rod-shaped bacteria that act as potentially opportunistic pathogens. With only a few documented case studies to date, Paenibacillus species are rarely the cause of a disease in humans.

Case summary

We report a case involving a 64-year-old male with known mild mitral regurgitation, who presented with fever and dyspnoea. Initially treated with empirical antibiotics, his blood cultures cultivated Paenibacillus thiaminolyticus, a previously unreported cause of endocarditis. Transoesophageal echocardiography demonstrated vegetations on the both leaflets of mitral valve along with severe mitral regurgitation, thus confirming a diagnosis of endocarditis. The patient was referred for cardiac surgery; however, the procedure was delayed due to complications related to a known hepatic cyst and additionally contraction of COVID-19 infection. The patient subsequently underwent mitral valve replacement without complications.

Discussion

Because of its rarity, guidelines to recommend specific antibiotics to treat Paenibacillus infective endocarditis are absent. To confirm the pathogen, molecular methods such as mass spectrometry or 16S rRNA sequencing are required. Early targeted antibiotic therapy and cardiac surgery are warranted to achieve good clinical outcomes.

Human Paenibacillus Infections: A Systematic Review with Comparison of Adult and Infant Cases

Neonatal infections due to Paenibacillus species have increasingly been reported over the last few years. We performed a structured literature review of human Paenibacillus infections in infants and adults to compare the epidemiology of infections between these distinct patient populations. Thirty-nine reports describing 176 infections met our inclusion criteria and were included. There were 37 Paenibacillus infections occurring in adults caused by 23 species. The clinical presentations of infections were quite variable. In contrast, infections in infants were caused by only 3 species: P. thiaminolyticus (112/139, 80%), P. alvei (2/139, 1%) and P. dendritiformis (2/139, 1%). All of the infants with Paenibacillus infection presented with a sepsis syndrome or meningitis, often complicated by extensive cerebral destruction and hydrocephalus. Outcomes were commonly poor with 17% (24/139) mortality. Cystic encephalomalacia due to brain destruction was common in both Ugandan and American cases and 92/139 (66%) required surgical management of hydrocephalus following their infection. Paenibacillus infections are likely underappreciated in infants and effective treatments are urgently needed.

Febrile sepsis: first report of human disease due to Paenibacillus silvae

Introduction

Paenibacillus species are saprophytes widely distributed in nature and rarely associated with overt human infection. Most cases have been described in people with important comorbidities and/or immunodepression. We report here what is, to the best of our knowledge, the first documented case of human disease due to Paenibacillus silvae , so far considered an exclusively environmental micro-organism.

Case presentation

A 57-year-old female patient was referred to our Unit after a 2 month history of remittent fever. Upon admission, a septic state and bacteraemia were revealed; P. sylvae was identified by 16S rRNA gene amplification and sequencing with matrix-assisted laser desorption/ionization-time of flight MS. The patient became afebrile after 9 days of antibiotic treatment and was completely cured after a 2 week regimen with intravenous amoxicillin-clavulanate plus oral doxycycline.

Conclusion

The patient did not report any previous episode of infection. Most of the well-known risk factors to Paenibacillus bacteraemia, i.e. invasive procedures, use of intravenous drugs and foreign bodies, could be excluded, although her immune system was probably impaired due to obesity and heavy smoking. We suggest that the isolation of bacteria belonging to the genus Paenibacillus should not be disregarded, since there is accumulating evidence that these organisms may cause disease even in immunocompetent subjects.

Cellular mechanisms and molecular pathways linking bitter taste receptor signalling to cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction in heart diseases

Heart diseases and related complications constitute a leading cause of death and socioeconomic threat worldwide. Despite intense efforts and research on the pathogenetic mechanisms of these diseases, the underlying cellular and molecular mechanisms are yet to be completely understood. Several lines of evidence indicate a critical role of inflammatory and oxidative stress responses in the development and progression of heart diseases. Nevertheless, the molecular machinery that drives cardiac inflammation and oxidative stress is not completely known. Recent data suggest an important role of cardiac bitter taste receptors (TAS2Rs) in the pathogenetic mechanism of heart diseases. Independent groups of researchers have demonstrated a central role of TAS2Rs in mediating inflammatory, oxidative stress responses, autophagy, impulse generation/propagation and contractile activities in the heart, suggesting that dysfunctional TAS2R signalling may predispose to cardiac inflammatory and oxidative stress disorders, characterised by contractile dysfunction and arrhythmia. Moreover, cardiac TAS2Rs act as gateway surveillance units that monitor and detect toxigenic or pathogenic molecules, including microbial components, and initiate responses that ultimately culminate in protection of the host against the aggression. Unfortunately, however, the molecular mechanisms that link TAS2R sensing of the cardiac milieu to inflammatory and oxidative stress responses are not clearly known. Therefore, we sought to review the possible role of TAS2R signalling in the pathophysiology of cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction in heart diseases. Potential therapeutic significance of targeting TAS2R or its downstream signalling molecules in cardiac inflammation, oxidative stress, arrhythmia and contractile dysfunction is also discussed.

Paenibacillus amylolyticus osteomyelitis in a Poodle dog: case report and literature review

Paenibacilli are gram-variable, endospore-forming bacteria that occupy various ecologic niches. These microorganisms have been known to infect humans occasionally at various anatomic sites. However, in humans, as well as in other vertebrate animals, the relationship between disease and isolation of Paenibacillus spp. remains poorly understood. We report here a case of infection in an adult Poodle dog. The animal had nodules in the lungs and multifocal osteolytic expansile bone lesions. From bone, Paenibacillus amylolyticus was recovered by culture and identified by MALDI-TOF mass spectroscopy and 16S rDNA sequencing; pyogranulomatous inflammation was observed in lung and bone specimens. The microorganism was resistant to clindamycin and imipenem. Four-month treatment with amoxicillin–clavulanate resulted in clinical resolution of disease in this dog. Nevertheless, therapy for more prolonged periods should be considered because recurrent infections can occur as a result of the transition of Paenibacillus spores to vegetative cells. Disease caused by a Paenibacillus species has not been reported previously in dogs, to our knowledge.

Severe Keratitis and Corneal Perforation by Paenibacillus glucanolyticus

PURPOSE

To report the first case of Paenibacillus glucanolyticus, a spore-forming bacteria, to be isolated in a human ocular infection.

METHODS

We describe a severe case of noncontact lens-related microbial keratitis due to P. glucanolyticus presenting with a large corneal abscess, severe ocular inflammation, and a large epithelial defect.

RESULTS

The corneal scrapes with no growth initially cultured P. glucanolyticus on blood agar after 48 hours, with sensitivity to gentamicin and fluoroquinolones. No other organism was cultured. The patient had severe keratitis with a protracted course requiring cyanoacrylate glue patching because of keratolysis and perforation. The patient may benefit from a penetrating keratoplasty and extracapsular cataract extraction in due course to aid visual rehabilitation.

CONCLUSIONS

This is the first reported ocular case of P. glucanolyticus demonstrating its bacterial virulence and pathogenic potential when infecting the cornea. Rapid identification with newer technology enable us to accurately identify these opportunistic bacteria and may give a more favorable visual outcome as correct sensitivities lead to timely treatment administration.

Paenibacillus oralis sp. nov., Isolated from Human Subgingival Dental Plaque of Gingivitis Lesion

A Gram-stain-negative, facultative anaerobic, spore-forming, motile, and rod-shaped bacterium, strain ChDC PVNT-B20^T, was isolated from the human subgingival dental plaque of a gingivitis lesion. Phylogenetic analysis based on the 16S ribosomal RNA gene (16S rDNA) showed that the strain belonged to the genus Paenibacillus. BLAST analysis of 16S rDNA sequence of the strain displayed high identity to those of Paenibacillus faecis DSM 23593^T (97.7% similarity) and Paenibacillus macerans ATCC 8244^T (97.6% similarity). Draft genome of strain ChDC PVNT-B20^T was composed of 8,112,407 bp. The DNA G+C content of the strain was 51.3 mol%. Average nucleotide identity values between strain ChDC PVNT-B20^T and P. faecis DSM 23593^T or P. macerans ATCC 8244^T were 75.71% and 91.5%, respectively. Genome-to-genome distance values between strain ChDC PVNT-B20^T and P. faecis DSM 23593^T or P. macerans ATCC 8244^T were 21.6% (19.3-24.0%) and 44.9% (42.3-47.4%), respectively. Major cellular fatty acids of strain ChDC PVNT-B20^T were anteiso-C_15:0 (43.4%), C_16:0 (16.6%), iso-C_16:0 (14.4%), and anteiso-C_17:0 (12.4%). The sole respiratory quinone of the strain was menaqinone-7. Major polar lipids of the strain were phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), and one unidentified glycolipid (GL). Minor polar lipids were one unidentified aminolipid (AL), one unidentified phospholipid (PL), and three unidentified lipids (L1-L3). Based on these results, strain ChDC PVNT-B20^T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus oralis sp. nov. is proposed. Type strain is ChDC PVNT-B20^T (= KCOM 3021^T = JCM 33462 ^T).

Bacterial contamination of human skin allografts and antimicrobial resistance: a skin bank problem

Background

Bacterial contamination remains the major problem in skin banks, even after antimicrobial treatment, and results in high rates of tissue discarding. This study aimed to analyze bacterial contamination in 32 human skin allografts from the skin bank of Dr. Roberto Corrêa Chem from the Hospital Complex Santa Casa de Misericórdia de Porto Alegre. These samples were already discarded due to microbial contamination. The identification of the bacteria isolated from skin allografts was performed by matrix assisted laser desorption ionization–time of flight. The antimicrobial susceptibility of the isolates to six different classes of antimicrobials was determined using the disk-diffusion agar method, and the evaluation of the inhibitory potential was determined by the minimal inhibitory concentration (50/90) of antimicrobials already used in the skin bank and those that most isolates were susceptible to.

Results

A total of 21 (65.6%) skin samples were contaminated with Gram-positive bacteria: 1 (4.7%) with Paenibacillus sp., 12 (61.9%) with Bacillus sp., 6 (28.5%) with Staphylococcus sp., and 2 (9.5%) with Bacillus sp. and Staphylococcus sp. Several resistance profiles, including multiresistance, were found among the isolates. Most of the isolates were susceptible to at least one of the antimicrobials used in the skin bank. All isolates were susceptible to amikacin, gentamicin, and tetracycline, which demonstrated the best inhibitory activities against the isolates and were considered as potential candidates for new antimicrobial treatments.

Conclusions

Bacillus, Paenibacillus, and Staphylococcus were isolated from the skin allografts, thus demonstrating the predominance of Gram-positive bacteria contamination. Other factors not related to the resistance phenotype may also be involved in the persistence of bacterial isolates in the skin allografts after antibiotic treatment. Gentamicin, amikacin, and tetracycline can be considered as an option for a more effective treatment cocktail.

Electronic supplementary material

The online version of this article (10.1186/s12866-018-1261-1) contains supplementary material, which is available to authorized users.

Intraoperative diagnosis of mitral valve endocarditis secondary to Paenibacillus provencensis

We report the first case of infective endocarditis caused by Paenibacillus provencensis. A mitral valve vegetation was incidentally discovered by intraoperative transoesophageal echocardiography in a 70-year-old woman undergoing aortic valve replacement. The precise identification of the causative agent was by means of genotypic characterisation with 16S rDNA gene sequencing. The patient was successfully treated with a 6-week course of antibiotics postoperatively, following debridement of the valve vegetation.

Non-contiguous-Finished Genome Sequence and Description of Paenibacillus camerounensis sp. nov

Strain G4(T) was isolated from the stool sample of a wild gorilla (Gorilla gorilla gorilla) from Cameroon. It is a facultative anaerobic, Gram-negative, rod-shaped bacterium. This strain exhibits a 16S rRNA nucleotide sequence similarity of 97.48% with Paenibacillus typhae, the phylogenetically closest species with standing nomenclature. Moreover, the strain G4(T) presents some phenotypic differences when compared to other Paenibacillus species and shows a low MALDI-TOF Mass Spectrometry score that does not allow any identification. Thus, it is likely that this strain represents a new species. Here, we describe the characteristics of this organism, complete genome sequence, and annotation. The 6,933,847 bp size genome (1 chromosome but no plasmid) contains 5972 protein-coding genes and 54 RNAs genes, including 44 tRNA genes. In addition, digital DNA-DNA hybridization values for the genome of the strain G4(T) against the closest Paenibacillus genomes range between 19.7 and 22.1, once again confirming its new status as a new species. On the basis of these polyphasic data, consisting of phenotypic and genomic analyses, we propose the creation of Paenibacillus camerounensis sp. nov. that contains the strain G4(T).

Identification and Pathogenic Potential of Clinical Bacillus and Paenibacillus Isolates

The soil-related Bacillus and Paenibacillus species have increasingly been implicated in various human diseases. Nevertheless, their identification still poses problems in the clinical microbiology laboratory and, with the exception of Bacillus anthracis and Bacillus cereus, little is known on their pathogenicity for humans. In this study, we evaluated the use of matrix-assisted laser desorption—ionization time of flight mass spectrometry (MALDI-TOF MS) in the identification of clinical isolates of these genera and conducted genotypic and phenotypic analyses to highlight specific virulence properties. Seventy-five clinical isolates were subjected to biochemical and MALDI-TOF MS identification. 16S rDNA sequencing and supplemental tests were used to solve any discrepancies or failures in the identification results. MALDI-TOF MS significantly outperformed classical biochemical testing for correct species identification and no misidentification was obtained. One third of the collected strains belonged to the B. cereus species, but also Bacillus pumilus and Bacillus subtilis were isolated at high rate. Antimicrobial susceptibility testing showed that all the B. cereus, B. licheniformis, B. simplex, B. mycoides, Paenibacillus glucanolyticus and Paenibacillus lautus isolates are resistant to penicillin. The evaluation of toxin/enzyme secretion, toxin-encoding genes, motility, and biofilm formation revealed that B. cereus displays the highest virulence potential. However, although generally considered nonpathogenic, most of the other species were shown to swim, swarm, produce biofilms, and secrete proteases that can have a role in bacterial virulence. In conclusion, MALDI-TOF MS appears useful for fast and accurate identification of Bacillus and Paenibacillus strains whose virulence properties make them of increasing clinical relevance.

The characteristics and outcome of infective endocarditis involving implantable cardiac devices

Infection of implantable cardiac electronic devices in particular lead endocarditis (cardiac device infective endocarditis (CDIE)) is an emerging problem with significant morbidity, mortality and health care costs. The epidemiology is characterised with advanced age and health care association in cases presenting within 6 months of implantation. Risk factors include those of the patient, the procedure and the device. Staphylococcal species predominate as the causative organisms. Diagnosis is reliably made by blood cultures and transesophageal echocardiography. Complications include pulmonary and systemic emboli, persistent bacteremia and concomitant valvular involvement. Management includes complete device removal and prolonged antimicrobial therapy. With long-term follow-up to 1 year, the mortality of CDIE is as high as 23 %. It is associated with patient co-morbidities and concomitant valvular involvement and may be prevented by device removal during index admission.

Non-contiguous finished genome sequence and description of Paenibacillus gorillae sp. nov

Strain G1(T) sp. nov. is the type strain of Paenibacillus gorillae a newly proposed species within the genus Paenibacillus. This strain, whose genome is described here, was isolated in France from the fecal sample of a wild western lowland gorilla from Cameroon. P. gorillae is a facultative anaerobic, Gram-negative, rod-shaped bacterium. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 6,257,967 bp long genome (one chromosome but no plasmid) contains 5,856 protein-coding and 62 RNAs genes, including 60 tRNA genes.