Case Report: Multidrug Resistant Raoultella ornithinolytica in a Septicemic Calf

Detection and Antimicrobial Resistance of Enterobacteriaceae other than Escherichia Coli in Raccoons from the Madrid Region of Spain

Introduction

Raccoons are an invasive alien species widely distributed in the Madrid region of Spain. These animals can carry a variety of enteric bacteria with associated antimicrobial resistance, which can infect humans and livestock. However, to our knowledge, the presence of non-E. coli Enterobacteriaceae in raccoons has not been previously studied.

Material and Methods

We conducted a study to examine the species distribution of Enterobacteriaceae isolates other than E. coli, as well as their antimicrobial resistance, in the faeces of 83 raccoons in the Madrid region.

Results

We detected 12 Enterobacteriaceae isolates other than E. coli belonging to seven different species: Citrobacter freundii (1 isolate), Citrobacter gillenii (3 isolates), Citrobacter murliniae (1 isolate), Citrobacter portucalensis (2 isolates), Enterobacter hormaechei subsp. hoffmannii (1 isolate), Hafnia paralvei (2 isolates) and Raoultella ornithinolytica (2 isolates). These isolates were found in 7 of the 83 (8.4%) animals studied. To our knowledge, this study is the first report of the presence of non-E. coli Enterobacteriaceae in raccoon faeces. All isolates but one were resistant to at least one of the 14 antimicrobials tested. Resistance to ampicillin (83.3%), amoxicillinclavulanic acid (50%) and cefoxitin (33.3%) was the most frequent.

Conclusion

Our study indicates that raccoons are a potential source of infection with Enterobacteriaceae other than E. coli for humans and livestock in the Madrid region.

Analysis of Anti-Infective Treatment of 9 Neonates with Raoultella ornithinolytica Sepsis

Raoul ornithine-releasing bacteria widely exist in water, plants, and soil, and colonize the digestive tract and upper respiratory tract of the human body. They are aerobic, unpowered, and capsular opportunistic pathogens. The infectivity of this bacterium is still uncertain, but the possibility of nosocomial infection has been mentioned in the literature. Studies have pointed out that the bacterium should be diagnosed in time and sensitive antibiotics should be used early. Once complicated with sepsis, it can cause multiple organ failure with a poor prognosis. In this study, we retrospectively analyzed the clinical data of nine cases of neonatal L. ornithine septicemia, to explore the clinical characteristics of neonatal L. ornithine septicemia and anti-infection therapy.

Insights to antimicrobial resistance: heavy metals can inhibit antibiotic resistance in bacteria isolated from wastewater

The alarming upsurge in the co-existence of heavy metal and antibiotic resistance may have a devastating impact on humans, animals, and the environment. Four metal-resistant bacteria were isolated from hospital effluents and industrial drain. Heavy metal resistance and antimicrobial resistance were examined in the isolates followed by identification through 16S rRNA gene sequencing. Delftia tsuruhatensis strain FK-01 and Carnobacterium inhibens strain FK-02 tolerated arsenic with maximal tolerated concentration (MTC) of 30 mM and 10 mM, respectively. Staphylococcus hominis strain FK-04 tolerated copper up to 4 mM and lead-resistant Raoultella ornithinolytica strain FK-05 exhibited tolerance to 1 mM lead. The growth kinetics of bacteria were monitored in the presence of metals and the following antibiotics, tetracycline, chloramphenicol, and kanamycin. The presence of arsenate significantly enhanced tetracycline resistance in C. inhibens. Heavy metal-induced antibiotic resistance was also observed in S. hominis and R. ornithinolytica, against chloramphenicol and tetracycline respectively. D. tsuruhatensis showed resistance to kanamycin but when grown in the presence of arsenic and kanamycin, bacteria lost resistance to the antibiotic. Therefore, it is suggested that the novel arsenate-resistant strain Delftia tsuruhatensis FK-01 has a unique ability to inhibit antimicrobial resistance that can be harnessed in bioremediation.