Leuconostoc pseudomesenteroides Bacteremiae in a Patient with Malignancy: A Case Report

Leuconostoc spp. are members of Streptococcus family that can be found in plants and dairy products as well as in feces and vaginal flora of humans. Unlike other streptococci, they have intrinsic resistance to vancomycin. Although it is a very rare pathogen of humans, it may cause serious infections, especially in immunocompromised hosts. In this paper, we present a case of soft tissue infection with bacteremia caused by Leuconostoc pseudomesenteroides that was cured with daptomycin. A forty-year-old obese woman was admitted with fever and cellulitis of right arm. She had a history of invasive ductal carcinoma operation on her right breast and chronic right arm lymphedema. Piperacillin-tazobactam was initiated. After 48 hours, the clinical findings did not improve and teicoplanin was added to the therapy. At the 72th hour, fever continued, cellulitis spread to the chest wall and bullous lesions appeared on the right hand. The treatment was switched to daptomycin. Leuconostoc pseudomesenteroides was isolated in blood cultures of the patient. It was susceptible to linezolid, ampicillin minimum inhibitory concentration (MIC=2), ciprofloxacin (MIC <0.5) and erythromycin (MIC=0.25). It was resistant to vancomycin and clindamycin (MIC=2). On the second day of daptomycin treatment, the patient was afebrile. On the 14th day of daptomycin treatment, the patient was discharged with nearly complete regression of erythema, crusted bullous lesions, and normal laboratory findings. In conclusion, Leuconostoc spp. may cause serious infections in patients with risk factors. This microorganism must be kept in mind when Gram-positive bacteria with the characteristics of Streptococcus spp, and resistant to vancomycin are isolated

The detection of Brucella spp. by BACTEC 9050 blood culture system

Otomatize, sürekli izlemeli kan kültürü sistemleri ile Brucella cinsi bakterilerin hızlı ve etkili bir şekilde belirlendiği bildirilmektedir. Bu retrospektıf çalışmada, BACTEC 9050 otomatize kan kültür sistemiyle, yavaş üreme özelliği gösteren bu bakterilerin üretilmesi değerlendirilmiştir. Çalışmaya, BACTEC 9050 sistemiyle kan kültürü çalışması yapılan, brusellozis tanısı almış 60 hasta dahil edilmiştir. İki kan kültürü alınan 31 hastanın 26'sında (%83.9), bir kan kültürü alınan 29 hastanın ise 17'sinde (%58.6) Brucella spp. izole edilmiştir. En erken olarak iki örnekte 3. günde üreme belirlenirken, örneklerin çoğunda (%84.1) üreme ilk 7 gün içinde belirlenmiştir. Bir örnekte pozitifliğin belirlenmesi 11. güne kadar uzamış, 8 örnekte ise 30 günü takiben yapılan kör pasajlar ile bakteri izole edilmiştir. BACTEC 9050 kan kültür sistemi ile Brucella cinsi bakterilerin izolasyonu için 5 veya 7 günlük inkübasyon protokollerinin yeterli olmadığı görülmektedir. İki kan kültürü örneği alınmış olması, uzun süreli inkübasyon ve takiben kör pasajların yapılması bakteri izolasyon şansını artırmaktadır.Recent reports have demonstrated that automated continous monitoring blood culture systems are fast and efficent in the detection of Brucella spp. In this retrospective study, the detection of these slow-growing bacteria by BACTEC 9050 blood culture system was evaluated. For this purpose, 60 patients, whose blood cultures were monitored by using BACTEC 9050 system were included into the study. Brucella spp. were isolated in 26 of 31 patients from whom two blood cultures were obtained and in 17 of 29 patients from whom single blood culture were obtained. The majority of isolates (84.1%) were detected within 7 days of incubation while the earliest detection was on the 3rd day in two samples. However, the bacteria were isolated by subcultures after 30 days of incubation in 8 of the samples. In conclusion, the routine 5 or 7 days-incubation protocols with BACTEC 9050 system were not efficient for the isolation of Brucella spp. Obtaining two blood cultures and prolonged incubation followed by subcultures increased the probability of bacterial isolation