RESUMEN
Pulsed-field gel electrophoresis (PFGE) has historically been considered the gold standard in fingerprinting bacterial strains in epidemiological studies and outbreak investigations; little is known regarding its use in individual clinical cases. The current study detailed two clinical cases in which PFGE helped to determine the source of their methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. Patient A was found to have MRSA bacteremia after trauma in her pelvic area. MRSA was also found in her groin but not in her nostril and rectum. PFGE was performed that showed variable bands of her MRSA isolates from blood and groin, suggestive of different strains of MRSA. Her MRSA bacteremia was determined to be unrelated to her pelvic trauma. Patient B was found to have MRSA bacteremia after colonoscopy. MRSA was also found in his nostril and rectum. PFGE was performed that showed variable bands of his MRSA isolates from blood and rectum but identical bands of MRSA isolates from his blood and nostril. His MRSA bacteremia was determined to be unrelated to his colonoscopy procedure. The current study demonstrates the use of PFGE to rule out the source of bacteremia in individual clinical cases.
RESUMEN
To date, Yersinia pestis, Yersinia enterocolitica, and Yersinia pseudotuberculosis are the three Yersinia species generally agreed to be pathogenic in humans. However, there are a limited number of studies that suggest some of the "non-pathogenic" Yersinia species may also cause infections. For instance, Yersinia frederiksenii used to be known as an atypical Y. enterocolitica strain until rhamnose biochemical testing was found to distinguish between these two species in the 1980s. From our regional microbiology laboratory records of 18 hospitals in Eastern Ontario, Canada from 1 May 2018 to 1 May 2021, we identified two patients with Y. frederiksenii isolates in their stool cultures, along with their clinical presentation and antimicrobial management. Both patients presented with diarrhea, abdominal pain, and vomiting for 5 days before presentation to hospital. One patient received a 10-day course of sulfamethoxazole-trimethoprim; his Y. frederiksenii isolate was shown to be susceptible to amoxicillin-clavulanate, ceftriaxone, ciprofloxacin, and sulfamethoxazole-trimethoprim, but resistant to ampicillin. The other patient was sent home from the emergency department and did not require antimicrobials and additional medical attention. This case series illustrated that diarrheal disease could be associated with Y. frederiksenii; the need for antimicrobial treatment should be determined on a case-by-case basis.
RESUMEN
To date, there is only one published report of an outbreak of urinary tract infections by Salmonella species after cystoscopy. Disinfection procedures for cystoscope have come into question. The current study aimed to determine the odds of developing Salmonella bacteriuria after cystoscopy. A retrospective case-control study was conducted on all patients with Salmonella species in urine (case) and blood (control) from 2017 to 2019 in 16 hospitals in Eastern Ontario, Canada. Eight of the 11 patients had cystoscopy prior to Salmonella bacteriuria; three of the 74 patients had urological procedures prior to Salmonella bacteremia, but none of their procedures were cystoscopy. The odds ratio of urological procedures with Salmonella bacteriuria was 63.1 (95% CI 10.9 to 366.6; p < 0.0001). In the bacteriuria group, the most frequently identified isolates were Salmonella enteritidis (n = 8), followed by Salmonella oranienburg, and Salmonella heidelberg. Seven of the S. enteritidis isolates had identical susceptibilities (ampicillin-sensitive; sulfamethoxazole/trimethoprim-sensitive; ciprofloxacin intermediate). In the bacteremia group, the most frequently identified isolates were S. enteritidis (n = 22), followed by Salmonella typhi, S. heidelberg, S. oranienburg, and Salmonella typhimurium. The result suggested cystoscopy is a risk factor for Salmonella bacteriuria. Identification of Salmonella bacteriuria should prompt public health investigations of linkage between cystoscopy and Salmonella bacteriuria.
RESUMEN
Microbacterium species are gram positive coryneforms generally considered as a contaminant when identified in gram stain of blood culture, especially when time-to-positivity is longer than 48 h. We encountered a case of infective endocarditis associated with Microbacterium maritypicum bacteremia, which became positive after 48 h of incubation in three out of four bottles. The antimicrobial management is controversial as vancomycin is generally assumed to cover most gram positive bacilli, but our susceptibility result demonstrated minimum inhibitory concentration of 4 µg/mL of vancomycin, indicating non-susceptibility. To the best of our knowledge, this is the first case report of infective endocarditis associated with Microbacterium maritypicum.