Brain abscess caused by Porphyromonas gingivalis and Eubacterium nodatum mimicking acute stroke

We described a case of a 65-year-old man with a brain abscess caused by Porphyromonas gingivalis and Eubacterium nodatum. The patient presented right central facial nerve palsy, mutism and right hemiparesis at the examination. The patient underwent a left frontal craniotomy with evacuation of the brain abscess. Specimens were collected for microbiological analysis and intravenous treatment was started with levetiracetam, dexamethasone, meropenem (1 g/8 h) and linezolid (600 mg/12 h). After identification of anaerobic bacteria the antibiotic treatment was changed to piperacillin/tazobactam (4 g/0,5 g/8 h), fulfilling 8 weeks of antibiotic with good clinical and radiological evolution.

Disseminated Nocardia farcinica infection associated with bacteraemia and osteomyelitis pubis in an elderly patient

OBJECTIVE

We describe a rare case of a disseminated Nocardia farcinica infection associated with hip osteomyelitis.

METHODS

A 91-year-old female patient was admitted with oedema of her right leg, fever of 38 °C and data consistent with ruptured Baker's cyst. A disseminated Nocardia farcinica infection including bloodstream infection, pneumonia and multiple abscesses along both lower limbs was observed.

RESULTS

After a four-week course of 320 mg/1600 mg/12 h of intravenous trimethoprim/sulfamethoxazole and multiple chirurgic drainages the patient was discharged with oral trimethoprim/sulfamethoxazole. Nevertheless, the patient expired done month after being discharged from the hospital.

CONCLUSIONS

The implementation of a combination of intravenous antibiotics and drainages resulted in an initial improvement in the patient's condition. However, despite these interventions, the patient ultimately passed away probably due to natural causes.

Description of eight human infections caused by Bacteroides pyogenes in a tertiary hospital of northern Spain

Bacteroides pyogenes is a Gram-negative obligate anaerobe, saccharolytic, non-motile, non-pigment-producing and non-spore-forming rod. Reports of human infections caused by B. pyogenes are scarce, with approximately 30 cases documented in scientific literature. The aim of this study was to describe the clinical characteristics of 8 different patients and to study the in vitro antibiotic susceptibility of the strains, as well as to evaluate the in vivo activity of the prescribed treatments. We conducted a descriptive retrospective study by searching all B. pyogenes isolates from January 2010 to March 2023 at the Basurto University Hospital. This included all cases, both in monomicrobial or polymicrobial cultures. Among the eight patients, three experienced severe infections such as bacteremia and osteomyelitis. All the strains were susceptible to amoxicillin/clavulanic acid, piperacillin/tazobactam, imipenem, meropenem, clindamycin, metronidazole and moxifloxacin.

A case of septic arthritis caused by Capnocytophaga canimorsus in an HIV patient

Invasive infections caused by Capnocytophaga canimorsus, a Gram-negative rod found in the oral cavity of healthy dogs and cats, are rare but they are increasing worldwide. We report a case of septic arthritis in a native knee joint due to this micro-organism. A 57-year-old man, with a well-controlled chronic HIV infection, attended the Emergency Department because of left knee pain and shivering without measured fever. A knee arthrocentesis and a computed tomography scan were performed, revealing septic arthritis with collections in the left leg posterior musculature. He was admitted to the Infectious Diseases Department for antibiotic treatment. Initial synovial fluid was inoculated in blood culture bottles, and the anaerobic one was positive after 63 h. Gram stain revealed fusiform Gram-negative rods, identified as C. canimorsus by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) directly from the bottle. Identification was confirmed by 16S rRNA sequencing and serotyping was performed by PCR, with serovar A as the outcome. Due to an unfavourable clinical course, the patient required two surgical cleanings and after appropriate antibiotic treatment he was discharged 2 months later.