Journal of Clinical Immunology Research

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Abstract - Journal of Clinical Immunology Research (2020) Volume 3, Issue 1

Allergy 2019 : A case of Providencia rettgeri sepsis biochmically misidentified as Escherichia coli - Soohyun Kim - Seegene Medical Foundation

Providencia rettgeri, belonging to the family Enterobacteriaceae, is a gram negative bacterium. P. rettgeri has been isolated from multiple animal reservoirs, including flies, birds, cats, dogs, cattle, sheep, guinea pigs, and penguins, and are resident oral flora in reptiles such as pythons, vipers, and boas. Providencia species are also found commonly in soil, waters and, therefore, seems to be widely distributed in nature. P rettgeri has been isolated in crocodiles with meningitis/septicemia and in chickens with enteritis.

In humans, P. rettgeri is associated with hospital acquired infections, including catheter-related urinary tract infections, bacteremia, skin infections, diarrhea, and gastroenteritis. A case report found P. rettgeri to be a cause of ocular infections, including keratitis, conjunctivitis, and endophthalmitis.

Automated identification systems that use biochemical reactions are known to accurately identify Enterobacteriaceae species. However, the accurate identification of some Enterobacteriaceae by the automated identification systems may be problematic because of their inconsistent biochemical profiles. There are some reports of misidentification of Providentia stuartii by commercial system, but there is no report for P. rettgeri. In this study, we report the case of P. rettgeri misidentified as E. coli with VITEK 2 system from patients with sepsis due to complicated urinary tract infection. 

Case Report

A 77-year-old female patient admitted with drowsy mental status. She was suffering from hypertension and diabetes for 35 years, and had a history of cystostomy due to neurogenic bladder six years ago. She was diagnosed with Parkinson’s disease and bedridden for 1 year.

At admission, her body temperature, pulse, respiration rate, and blood pressure were 38.2?, 106/min, 24/min, and 66/45mmHg, respectively. Her complete blood count showed that white blood cell count was 31,000/μL (absolute neutrophil count 30,300/μL) and platelet count was 178,000/μL. The values of C-reactive protein and procalcitonin were 21.24 mg/dL and 188.51 ng/mL, respectively. Two sets of blood cultures and one urine culture were obtained before administration of antibiotics. After 24-hour incubation of blood culture bottles, gram negative rods were detected, subculture showed non-hemolytic grayish colonies on blood agar and colorless colonies on MacConkey agar.

The VITEK 2 Gram-negative (GN) identification card (bioMerieux, Marcy l’Etoile, France) was used to identify the strain. The VITEK 2 system identified this strain as E. coli with an ambiguous confidence level (85% probability). The same result was obtained when the GN card was repeated. Additional biochemical tests showed urease positive and alkaline slant/acidic butt with gas production for triple sugar iron test. In addition, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was conducted by Bruker Biotyper (Bruker Daltonics, Leipzig, Germany) and we could obtain result of P. rettgeri. The sequence analysis of 16S rRNA gene confirmed P. rettgeri (Genbank: NR042413.1).

Antimicrobial susceptibility testing was performed by using VITEK 2 system. This strain was resistant to ertapenem and imipenem. Further, modified Hodge test was negative and carbapenemase inhibition test was positive for phenylboronic acid positive but negative for ethylenediaminetetraacetic acid. PCRs for five carbapenemase-encoding genes (NDM-1, KPC, VIM, IMP, GES and OXA-48) were all negative.

In spite of administration of antibiotics and supportive care, she expired due to heart failure 29 days after admission.

 

Discussion

P. rettgeri is in the genus Providencia, along with P. stuartii, Providencia alcalifaciens, Providencia heimbachae, and Providencia rustigianii. The first species of the genus now known as Providencia was isolated by Rettger in 1904. However, the bacterium was not submitted to detailed study until 14 years later, when it was further characterized and named Bacterium rettgeri by Hadley et al. Then, Kauffmann first proposed the genus name Providencia in 1952.

In this case, two biochemical test results of the VITEK 2 GN card (negative for adonitol fermentation and citrate utilization) varied between the current strain and previously identified P. rettgeri strains. It was demonstrated that nearly 0% of P. rettgeri is negative for adonitol fermentation, whereas 95% of E. coli is negative for the adonitol fermentation. Moreover, it was demonstrated that 4-5% of P. rettgeri is negative for citrate utilization, whereas 99% of E. coli is negative for the citrate utilization. The infrequent negative results for adonitol fermentation and citrate utilization may mislead the GN card to misidentify P. rettgeri as E. coli. This shows that we have to be aware of the limits on the automated VITEK 2 system to identify some strains which have variable biological characteristics.

Providencia infections are uncommon and are usually nosocomial. They represent an emerging problem because of the increasing prevalence of antibiotic resistance secondary to extended-spectrum beta-lactamase (ESBL). Many Providencia isolates are resistant to numerous antibiotics. However, according to the knowledges about the antibiotic susceptibility, P. rettgeri strains are less resistant than other Providencia strains to aminoglycosides, cephalosporins and substituted penicillins. On the other hand, multi-resistant P. rettgeri strains and carbapenem-resistant P. rettgeri strain were also described. While carbapenem-resistant Enterobacteriaceae (CRE) remained uncommon in our health care system, the frequency of CRE increased. In this case, the strain was resistant to carbapenem and this is the first report of CRE of P. rettgeri in Korea. However, we failed to identify carbapenem resistance mechanism.

In summary, we report the case of P. rettgeri, which was not exactly identified by automated identification system that use biochemical reactions but confirmed by MALDI-TOF analysis and 16s rRNA gene sequence analysis. Based on sign from milestone clinical trials, ablation is safe and effective for treating Hepatitis, with virtually no risk of death. The results in the real world may be somewhat different, based upon the recent findings. According to the experts the mortality rates among 60,203 hepatitis after suffering catheter ablation between 2010 and 2015. The education included patients from through the country who were treated at a variety of medical centers, rather than the large academic centers that are normally included in clinical trials.

The increasing burden of cardiovascular disorders will intensify the demand for heart arrhythmia monitoring devices in the coming years. The occurrence of various cardiac dysrhythmias includes atrial flutter, bradycardia, Atrial Fibrillation between others is rising at a quick pace. According to the Public Health England, approx. 1.4 million people are suffering from atrial fibrillation, alongside with number of undiagnosed cases of the disease.

This type of heart condition needs timely and precise observing of the heart rhythm, in that way it boost up the adoption of cardiac arrhythmia monitoring devices over the estimate years. The Worldwide Heart Arrhythmia Market Analysis will spread over USD 8.0 billion by 2025. Growth of telemetric and mobile Hepatitis monitoring solutions will impel the global cardiac arrhythmia monitoring devices market growth in the forthcoming years.

 

Author(s): Soohyun Kim

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