Development of a simple and practical method of discrimination between Vibrio furnissii and V. fluvialis based on single-nucleotide polymorphisms of 16S rRNA genes observed in V. furnissii but not in V. fluvialis

Novel gas producing Vibrio cholerae: a case report of gastroenteritis with acute kidney injury

Background

Bacterial characterization is important in clinical and epidemiological studies. We herein report the first case of gas-producing Vibrio cholera gastroenteritis with acute kidney injury.

Case presentation

A 30-year-old female presented to the emergency department with complaints of about ten episodes of watery diarrhea, four episodes of vomiting and elevated serum urea/creatinine levels. Although the bacteria were first misidentified as Vibrio furnissii by gas production on carbohydrate fermentation and triple sugar iron agar, it was later confirmed as Vibrio cholerae by 16 S rRNA gene sequencing and specific PCR. The treatment regimen was followed as for Vibrio species with intravenous fluids, ciprofloxacin and doxycycline. The patient recovered without relapse.

Conclusions

Literature survey from the PubMed database shows no gas-producing Vibrio cholerae isolate being reported in the world. Further, genotype studies are warranted to look into the gas production of Vibrio cholerae.

Detection of microbial genes in a single leukocyte by polymerase chain reaction following laser capture microdissection

Although isolation and identification of bacteria in a clinical specimen constitute essential steps for the diagnosis of bacterial infection, positive results of the bacterial culture are not always attained, despite observing the bacteria by Gram staining. As bacteria phagocytosed by the leukocytes are considered as the causative agents of infectious diseases, this study aims to introduce a new approach for the collection of only bacteria phagocytosed by the neutrophils in an animal model using laser capture microdissection (LCM) followed by the DNA identification using polymerase chain reaction (PCR). We inoculated representative bacteria (Escherichia coli and Staphylococcus aureus) into the abdominal cavities of specific pathogen-free C57BL/6 J mice. After 6 h inoculation, we collected the fluid samples from the peritoneal cavities of mice and demonstrated peritonitis by the increase of neutrophils. Then, we smeared the neutrophils on the membrane slides and collected single-cell phagocytosing bacteria by LCM. The supernatant of the cell lysate was supplied for the PCR reaction to amplify the 16S rRNA gene, and we validated the DNA sequences specific for the inoculated bacteria. In addition, PCR using specific primers for E. coli and S. aureus identified each species of bacteria. Hence, this study suggests that the combination of LCM and PCR could be a novel approach to determine bacteria in infectious diseases. Nevertheless, further investigation is warranted to test various additional bacterial taxa to demonstrate the general applicability of this method to clinical samples.