Avaliação da mutagenicidade e antimutagenicidade de um biopolímero extraído do microorganismo Agrobacterium radiobacter em camundongos Swiss / Assessment of mutagenicity and antimutagenicity of a biopolymer extracted from the microorganism Agrobacterium radiobacter in mice

A presente pesquisa avaliou a ação mutagênica e antimutagênica de um biopolímero de glucose extraído da Agrobacterium radiobacter (Biopolímero de Agrobacterium radiobacter). O experimento foi realizado com camundongos Swiss machos divididos em oito grupos. O tratamento com o biopolímero foi realizado por gavage em dose única concomitante a uma dose de solução tampão fosfato nos grupos de avaliação da mutagenicidade, ou ao agente indutor de danos no DNA, ciclofosfamida, na concentração de 50 mg/kg (peso corpóreo - p.c.), nos grupos de avaliação da antimutagenicidade. Utilizou-se o teste de micronúcleo em sangue periférico e a coleta de sangue foi realizada 24 e 48 h após a aplicação das substâncias-teste. A análise estatística demonstrou que o biopolímero não possui atividade mutagênica e que é efetivo em prevenir danos no DNA. As porcentagens de redução de danos nos grupos de antimutagenicidade foram de 83,9 por cento, 89,1 por cento e 103,1 por cento em 24 h e 101,24 por cento, 98,14 por cento e 120,64 por cento em 48 h para as doses de 75, 150 e 300mg/kg (p.c.), respectivamente. A alta porcentagem de redução de danos associada à ausência de efeitos mutagênicos indica, além da atividade quimioprotetora, a possibilidade do biopolímero ser um alimento funcional candidato à utilização como co-adjuvante na quimioterapia para prevenir efeitos colaterais.

This study evaluated the mutagenic and ant mutagenic action of a biopolymer of glucose extracted from Agrobacterium radiobacter (Biopolymer of Agrobacterium radiobacter). The experiment was conducted with Swiss male mice divided into eight groups. Treatment with the biopolymer was performed in a single dose by gavage at a dose of concomitant phosphate buffer groups in the evaluation of mutagenicity, or the agent of inducing DNA damage, cyclophosphamide, the concentration of 50 mg/kg (body weight --b.w.), in groups of assessment ant mutagenic. We used the micronucleus test in peripheral blood. The blood sample was held 24 and 48 h after application of the test substances. Statistical analysis showed that the biopolymer has no mutagenic activity and it is effective in preventing damage to DNA. The percentages of damage reduction in groups of ant mutagenic were 83.9 percent, 89.1 percent and 103.1 percent in 24 h and 101.24 percent, 98.14 percent and 120.64 percent at doses of 48 to 75, 150 and 300 mg/kg (b.w.) respectively. The high percentage of damage reduction associated with the absence of mutagenic effects indicates the possibility of biopolymer chemoprotection action. It can also be considered a functional food candidate to be used as co-adjuvant chemotherapy to prevent side effects.

A Case of Agrobacterium radiobacter Sepsis following Oral Surgery in a Patient of Oral Cancer / 감염과화학요법

Agrobacterium is an aerobic, motile, oxidase-positive, and non-spore-forming gram-negative bacillus. Under laboratory conditions, Agrobacterium can genetically transform a wide range of other eukaryotic species. A plant-pathogenic soil inhabitant, Agrobacterium radiobacter is not characterized as a true human pathogen. It is an opportunistic pathogen of minor clinical significance and has been substantiated as a rare cause of bacteremia, endocarditis, urinary tract infection and peritonitis mostly in catheterized immunocompromised patients. The authors report a case of a 41-year-old female patient with sepsis caused by A. radiobacter bacteremia following wide excisional biopsy of adenoid-cystic carcinoma involving oral cavity. She was suffering from fever and chilling that developed on second post-operation day. Blood cultures yielded a gram-negative bacillus identified as A. radiobacter. She completely recovered with appropriate antibiotics treatment; levofloxacin and isepamicin. We experienced a case of sepsis due to A. radiobacter bacteremia without indwelling foreign body, which was treated successfully with antibiotics therapy.

A Case of Agrobacterium radiobacter Sepsis following Oral Surgery in a Patient of Oral Cancer / 감염과화학요법

Agrobacterium is an aerobic, motile, oxidase-positive, and non-spore-forming gram-negative bacillus. Under laboratory conditions, Agrobacterium can genetically transform a wide range of other eukaryotic species. A plant-pathogenic soil inhabitant, Agrobacterium radiobacter is not characterized as a true human pathogen. It is an opportunistic pathogen of minor clinical significance and has been substantiated as a rare cause of bacteremia, endocarditis, urinary tract infection and peritonitis mostly in catheterized immunocompromised patients. The authors report a case of a 41-year-old female patient with sepsis caused by A. radiobacter bacteremia following wide excisional biopsy of adenoid-cystic carcinoma involving oral cavity. She was suffering from fever and chilling that developed on second post-operation day. Blood cultures yielded a gram-negative bacillus identified as A. radiobacter. She completely recovered with appropriate antibiotics treatment; levofloxacin and isepamicin. We experienced a case of sepsis due to A. radiobacter bacteremia without indwelling foreign body, which was treated successfully with antibiotics therapy.

Isolation and Characterization of a Nicotine-degrading Strain Z7 / 中国生物工程杂志

A nicotine-degrading bacterial strain Z7 was isolated from tobacco growing soil at Zhangjiajie region in Hunan Province.The morphology,physiological and biochemical characteristics of strain Z7 were studied and the results showed that characteristics of this strain were essentially consistent with Agrobacterium radiobacter/tumefaciens.This strain degraded nicotine optimally at 30℃ and initial pH 7.0.It was able to utilize nicotine as its sole carbon source,and it could degrade 71% of nicotine under the optimized incubation conditions for 48 h.Meanwhile,the color of culture medium turned from yellowy to green and dark green,then it turned to brown.This strain might have potential applications in tobacco industry.

A Case of Agrobacterium Radiobacter Endophthalmitis following Cataract Surgery

PURPOSE: We report a case of Agrobacterium radiobacter endophthalmitis following cataract surgery and treated with pars plana vitrectomy and intravitreal antibiotics injection. METHODS: A 63 year-old male patient was transferred for the endophthalmitis following cataract surgery on his left eye. His initial visual acuity was hand motion. Slit lamp examination showed marked inflammatory cells in anterior chamber and vitreous opacity was seen in fundus examination with indirect ophthalmoscopy. We performed the removal of implanted IOL, pars plana vitrectomy and intravitreal antibiotics injection(Vancomycin 1.0 mg/0.1 ml, Ceftazidime 2.0 mg/0.1 ml). RESULTS: Gram stain results revealed the gram negative rods and bacterial culture identification revealed the Agrobacterium radiobacter using the RapID NF plus system. After 8 weeks, his corrected visual acuity is 0.3 and fundus examination shows the localized atrophic change and preretinal membrane in inferotemporal retina.

A Case of Agrobacterium radiobacter Peritonitis in a Patient on CAPD / 대한신장학회잡지

Agrobacterium radiobacter is a rare human pathogen and a few cases were reported in the world. The peritoneal cavity in patient maintained on peritoneal dialysis serves as an excellent incubator and culture medium for microorganisms. We experienced a rare human infection as peritonitis with A. radiobacter in Inha University Hospital, Inchon, Korea. The patient was 36 year-old female and maintained on CAPD for one year. She had two times of CAPD peritonitis. She visited to the hospital because of turbid peritoneal fluid. On initial physical examination, she showed mild abdominal tenderness and elevated body temperature. Laboratory findings showed leukocytosis and anemia with elevated serum creatinine level. The analysis of peritoneal fluid showed white blood cell count as many as 1860/mm3 and it's culture revealed A. radiobacter. She received vancomycin and aminoglycoside antibiotics via intraperitoneal route and the CAPD catheter was removed. She was maintained on hemodialysis and reveived isepamicin 100mg a day via intravenous for 7 days. We report our experience of peritonitis caused by A. radiobacter and review the literature of similar cases of peritonitis.