The overly attached bacteria

Abstract

Background: Chromobacterium violaceum is a Gram negative bacillus which is a common inhabitant of soil and water in tropical and subtropical regions. Infections involving humans are rare; only about 150 cases were reported worldwide up till 2004. Interestingly, the first case of human infection was reported in Malaysia back in 1927. Case Description: A 65 y old gentleman was electively admitted for (CABG) surgery. Post procedure, he developed temperature spikes and blood culture grew Chromobacterium violaceum. Subsequently, serial blood cultures persistently yielded the same organism despite being on various antibiotics. Transthoracic Echocardiography, Ultrasound Abdomen as well as CT Thorax, Abdomen and Pelvis to look for possible foci of infection or disseminated abscesses yielded negative results. Eventually patient was able to achieve bacteremic clearance after 1 m from the 1st positive blood culture. This was achieved after total 25 d of IV Ceftazidime, 48 d of IV Ciprofloxacin and Oral Bactrim for 61 d. Patient was discharged with further doses of Oral Bactrim and Oral Ciprofloxacin completing total 3 m. He was reviewed in clinic post discharge and remained well. Discussion: Chromobacterium violaceum are usually found in soil or water. Therefore, the reason our patient was able to acquire infection was unknown since he was already admitted for almost 1 m prior to first positive blood culture. Previous studies reported common predisposing factors were immunocompromised state, chronic granulomatous disease, steroid therapy, and diabetes among others, in which the patient did not fulfil. Another issue was with regards to antimicrobial agent of choice as well as duration of treatement. Considering that Chromobacterium infections are rare, there are very limited data and evidence on treatment regimes. There is no definite breakpoint for antibiotic susceptibility interpretation for Chromobacterium violaceum according to 2018 Clinical and Laboratory Standards Institute (CLSI) guidelines. The sensitivity results provided are based on non-lactose fermenter Gram negative bacillus breakpoints. Furthermore, the sensitivity testing was done in vitro; which does not directly translate to in vivo activity and response. Conclusion: Infections with Chromobacterium violaceum has been increasingly reported worldwide. Further studies and research into this organsism are required to improve patient management in the coming future.