BACKGROUND: Prevotella heparinolytica is a Gram-negative bacterium that is commonly found in the oral, intestinal, and urinary tracts. It has been extensively studied in lower respiratory tract infections in horses, which has heparinolytic activity and can secrete heparinase and further induces virulence factors in cells and causes disease. However, no such cases have been reported in humans.
METHODS: A 58-year-old male patient from China presented to the respiratory clinic in Suzhou with a productive cough producing white sputum for 20 days and fever for 3 days. Prior to this visit, a chest computed tomography scan was conducted, which revealed multiple patchy nodular opacities in both lungs. On admission, the patient presented with a temperature of 38.1 °C and a pulse rate of 110 beats per minute. Despite routine anti-infective treatment with moxifloxacin, his temperature fluctuated and the treatment was ineffective. The patient was diagnosed with Prevotella heparinolytica infection through metagenomic next-generation sequencing. Therefore, the antibiotics were switched to piperacillin-tazobactam in combination with ornidazole, which alleviated his symptoms; 1 week after discharge, the patient returned to the clinic for a follow-up chest computed tomography, and the opacities on the lungs continued to be absorbed.
CONCLUSIONS: Prevotella heparinolytica is an opportunistic pathogen. However, it has not been reported in human pneumonia. In refractory pneumonia, measures such as metagenomic next-generation sequencing can be used to identify pathogens and help guide antibiotic selection and early support.

BACKGROUND: Brain abscesses caused by Prevotella oris are rarely reported. Here, we described a case of a brain infection caused by Prevotella oris that was detected by metagenomic next-generation sequencing (mNGS).
METHODS: A 63-year-old man with no medical history reported headache in the right frontotemporal region, fever, and intermittent diplopia. Magnetic resonance imaging (MRI) revealed abnormal signals and enhancement changes in the superior sellar region. mNGS testing showed that cerebrospinal fluid collected from the spine was positive for Prevotella oris. After receiving a combined treatment of antibiotic therapy, the patient recovered well.
CONCLUSIONS: We reviewed the relevant literature and summarized the characteristics and prognosis of this type of bacterial infection to provide ideas for clinicians to diagnose and treat this disease.

Prevotella copri is an abundant member of the human gastrointestinal microbiome, whose relative abundance has curiously been associated with positive and negative impacts on diseases, such as Parkinson\'s disease and rheumatoid arthritis. Yet, the verdict is still out on the definitive role of P. copri in human health, and on the effect of different diets on its relative abundance in the gut microbiome. The puzzling discrepancies among P. copri studies have only recently been attributed to the diversity of its strains, which substantially differ in their encoded metabolic patterns from the commonly used reference strain. However, such strain differences cannot be resolved by common 16S rRNA amplicon profiling methods. Here, we scrutinize P. copri, its versatile metabolic potential, and the hypotheses behind the conflicting observations on its association with diet and human health. We also provide suggestions for designing studies and bioinformatics pipelines to better research P. copri.

Polymicrobial meningitis is a rare entity in the adult population, especially in the antibiotic era. However, disorders such as chronic suppurative otitis media (CSOM) or even poor oral hygiene are considered risk factors for the development of such cerebral infection. We report a case of polymicrobial meningitis associated with oto-mastoiditis in a 64-year-old female patient known to have CSOM. The patient presented atypical symptoms for community-acquired meningitis, showing subacute evolution of headache, without fever or neck stiffness. The aerobe microorganisms Streptococcus anginosus and Corynebacterium spp., sensitive to beta-lactamines, and the anaerobe Prevotella spp., resistant to penicillin and metronidazole, were isolated from CSF specimens, while Proteus mirabilis and Enterococcus faecalis were identified from the ear drainage. The diversity of pathogens identified in our case led us to the hypothesis of two different sources of meningitis: otogenic and/or odontogenic. Favorable evolution was obtained after a multi-disciplinary approach, combining surgery and broad-spectrum antibiotics. In addition, we performed a literature review that highlights the low incidence of polymicrobial mixed aerobe-anaerobe meningitis.

Septic arthritis is a medical emergency that requires prompt diagnosis to prevent long-term intra-articular complications. Prevotella bivia is an anaerobic gram-negative rod which has been infrequently reported to cause septic arthritis. We present a 49-year-old female that presented with spontaneous left knee pain and swelling without history of insult to the knee. She was initially misdiagnosed with patellar tendinitis and gout but later underwent joint aspiration due to worsening symptoms, which demonstrated 60 800/µL nucleated cells with a polymorphonuclear burden consistent with septic arthritis. Arthroscopy with irrigation and drainage was subsequently performed, and the patient was started on empiric antibiotics while awaiting cultures. Cultures grew Prevotella bivia, and antibiotics were deescalated to ertapenem alone followed by oral metronidazole. Prevotella species as a source of septic arthritis is rare, and its occurrence in a patient without known insult to the knee is even more uncommon. It is essential that it is recognized to treat appropriately and prevent long-term loss of function in the joint.

Children often experience impalement trauma when they fall while holding objects in their mouths. While most cases heal without complications, here we report a case of buccal abscess formation after toothbrush trauma. A two-year-old boy fell while running with a toothbrush in his mouth, which punctured his right buccal mucosa. The following day, he presented to a pediatrician with a fever and buccal swelling and was treated with oral antibiotics. However, the buccal swelling did not improve, and the patient was referred to our department. Four days after the visit, the buccal swelling and fever worsened, requiring hospitalization, intravenous antibiotics, and drainage. The inflammation quickly disappeared following treatment, with no recurrence. Prophylactic antibiotic administration for oral impalement trauma is controversial. Our results suggest that prophylactic antibiotics covering both anaerobic and aerobic bacteria are necessary in cases of toothbrush-related oral trauma, where multiple bacterial infections may occur.

BACKGROUND: Infective arthritis is an orthopaedic surgical emergency. Staphylococcus aureus remains the commonest causative bacteria across all age groups. Prevotella spp. as a cause of infective arthritis is extremely rare.
METHODS: We present our case of a 30-year-old African male patient who presented with mild signs of infective arthritis of the left hip. His risk factors were his background retroviral disease, intravenous drug abuse, and a previous episode of left hip arthrotomy which healed expectantly with intervention. The current presentation was treated with arthrotomy of the hip, fluid lavage, and skeletal traction based on our clinical findings and the rarity of the presentation was seen to be mobilising non-weight bearing with crutches, and pain-free on the left hip.
CONCLUSIONS: A high index of suspicion for Prevotella Septic Arthritis (PSA) should be exercised when treating infective arthritis patients with background joint arthropathies, and intravenous drug abuse, especially in individuals with significant immunosuppression and/or recent tooth extraction. Fortunately, although rare an entity, good outcomes can be expected with early diagnosis and classic treatment principles of joint decompression and lavage as well as guided antibiotic therapy.

A 33-year-old male with a past medical history of asthma presented to the Emergency room with a three-day history of right-sided chest pain, productive cough with dark brown sputum, and shortness of breath. He was found to have right lower lobe consolidation consistent with acute pneumonia, and areas of non-homogenous density within the consolidation, suspicious of necrotizing pneumonia. Computed tomography (CT) of the chest with IV contrast revealed a large, irregular thick-walled cavitary mass involving the right middle lobe with surrounding ground glass cavitation. An extensive workup was negative, including a transbronchial biopsy. The case explains how a causative organism was detected.

Acute pancreatitis is one of the leading causes of gastrointestinal-related hospitalizations in the United States. One of the complications of acute pancreatitis is infected pancreatic necrosis. We present a rare case of acute necrotizing pancreatitis infected with Prevotella species in a young patient. We demonstrate the importance of early suspicion of complicated acute pancreatitis and the need for early intervention to prevent hospital re-admission and improve the morbidity and mortality associated with infected pancreatic necrosis.

Prevotella melanogenica is a typical organism present in the human oral cavity and female reproductive tract, which is responsible for causing periodontal disease and the inflammation of the female reproductive tract. The present report discusses the case of a young female patient who presented with cough and fever as the main clinical symptoms. Computed Tomography (CT) revealed multiple clusters of ground glass density shadows in both lungs, with network-like and paving stone-like changes. The alveolar lavage fluid was collected for next-generation sequencing, which revealed the presence of Prevotella melanogenica. The patient received treatments, CT revealed that the density of multiple flakes of ground glass density in both lungs was lower than the previously observed density. Prevotella melanogenica pneumonia is rare, and the paving stone symptom observed in CT is not specific. Therefore, the case reported here provides a novel perspective regarding the diagnosis of pneumonia.