Genome sequence of n-alkane-degrading Hydrocarboniphaga effusa strain AP103T (ATCC BAA-332T).

Hydrocarboniphaga effusa strain AP103(T) (ATCC BAA-332(T)) is a member of the Gammaproteobacteria utilizing n-alkanes as the sole source of carbon and energy. Here we report the draft genome sequence of AP103(T), which consists of 5,193,926 bp with a G + C content of 65.18%.

Involvement of two transport systems and a specific porin in the uptake of phthalate by Burkholderia spp.

Burkholderia spp. that degrade phthalate have an ABC transporter-type phthalate transport system (OphFGH) and a specific porin (OphP) in addition to a permease-type phthalate transporter (OphD). OphFGH has a lower K(m) and higher V(max) than OphD, which affects how the bacteria grow. OphP is involved in both mechanisms of transport.

Examination and expansion of the substrate range of m-hydroxybenzoate hydroxylase.

The gene encoding m-hydroxybenzoate hydroxylase (mobA) was cloned from Comamonas testosteroni GZ39. MobA converts m-hydroxybenzoate and to a lesser extent p-hydroxybenzoate to protocatechuate. To explore the structural and functional relationships in phenolic acid monooxygenases, MobA was subjected to in vitro mutagenesis by error-prone PCR and the mutant MobAs were screened for their ability to oxidize phenol or 3-aminophenol. A mutant MobA with a single V257A substitution was able to transform phenol to catechol, providing the first example of monooxygenase acting on phenolic acids that can also hydroxylate phenol. The mutant MobA also has enhanced ability to transform resorcinol, hydroquinone, p-hydroxybenzoate, 2,5-dihydroxybenzoate, 3,4-dihydroxybenzoate, 3-chlorophenol, 4-chlorophenol, 4-chlororesorcinol, and 4-nitrophenol. Several MobA mutants were obtained for their ability to transform 3-aminophenol to a related substituted catechol. Mutant MobAs with single amino acid substitutions (H135P, A400G, or D416A) were derived from these mutants and verified for their ability to transform 3-aminophenol.

Is Fournier's gangrene severity index useful for predicting outcome of Fournier's gangrene?

OBJECTIVES: Fournier's gangrene (FG) is a rare but life-threatening disease. Although antibiotics and aggressive debridement have been broadly accepted as the standard treatment, the mortality rate remains high. We conducted a retrospective study to analyze the outcome and identify the risk factors and prognostic indicators. METHODS: We retrospectively reviewed the medical records of 25 patients diagnosed with FG between July 1993 and August 2003. Data collected included age, predisposing factors, treatment modalities, length of hospital stay, surgical debridement times, and outcome. The FG severity index was used to predict outcome. Univariate analysis of the different prognostic factors was performed using t test and Fisher's exact probability test. RESULTS: All patients were male, 60% were diabetic, and the mean age was 55.8 years. The mean hospital stay was 20 days and the mortality rate was 32%. The mean age of 53.8+/-18.3 (SD) years in the survival group (n=17) was significantly lower than the 59.9+/-10.2 years (n=8) of the non-survival group (p<0.05). Non-survival group patients had lower serum hematocrit (mean 28.9, p=0.019) and albumin (mean 1.93, p=0.024) levels. In our series, the mean FG severity index for survivors was 4.41+/-2.45 (range 2-9) compared to 12.75+/-2.82 (range 9-18) for those who died (t test, p<0.0001). CONCLUSION: The survival rate of younger patients with FG was higher. We agree that a FG severity index cutoff value of 9 is an excellent predictor of outcome.

Characterization and regulation of the genes for a novel anthranilate 1,2-dioxygenase from Burkholderia cepacia DBO1.

Anthranilate (2-aminobenzoate) is an important intermediate in tryptophan metabolism. In order to investigate the degradation of tryptophan through anthranilate by Burkholderia cepacia, several plasposon mutations were constructed of strain DBO1 and one mutant with the plasposon insertion in the anthranilate dioxygenase (AntDO) genes was chosen for further study. The gene sequence obtained from flanking DNA of the plasposon insertion site revealed unexpected information. B. cepacia DBO1 AntDO (designated AntDO-3C) is a three-component Rieske-type [2Fe-2S] dioxygenase composed of a reductase (AndAa), a ferredoxin (AndAb), and a two-subunit oxygenase (AndAcAd). This is in contrast to the two-component (an oxygenase and a reductase) AntDO enzyme from Acinetobacter sp. strain ADP1, P. aeruginosa PAO1, and P. putida P111. AntDO from strains ADP1, PAO1, and P111 are closely related to benzoate dioxygenase, while AntDO-3C is closely related to aromatic hydrocarbon dioxygenases from Novosphingobium aromaticivorans F199 and Sphingomonas yanoikuyae B1 and 2-chlorobenzoate dioxygenase from P. aeruginosa strains 142 and JB2. Escherichia coli cells expressing the functional AntDO-3C genes transform anthranilate and salicylate (but not 2-chlorobenzoate) to catechol. The enzyme includes a novel reductase whose absence results in less efficient transformation of anthranilate by the oxygenase and ferredoxin. AndR, a possible AraC/XylS-type transcriptional regulator, was shown to positively regulate expression of the andAcAdAbAa genes. Anthranilate was the only effector (of 12 aromatic compounds tested) that was able to induce expression of the genes.

Hydrocarboniphaga effusa gen. nov., sp. nov., a novel member of the gamma-Proteobacteria active in alkane and aromatic hydrocarbon degradation.

Novel alkane-degrading strains of bacteria were isolated from soil contaminated with fuel oil from a leaking underground tank in New Jersey, USA. Two phenotypically similar strains (designated AP102 and AP103T) possessed 16S rRNA sequences unique among the majority of known hydrocarbon-degrading bacteria. The 16S rRNA sequences showed a moderate but distant relationship to the genus Nevskia and a substantial similarity to strains that had previously been isolated for growth on phenol (in Japan) and on toluene (in Canada) by other researchers. The hydrocarbon-degrading strains from Japan, Canada and New Jersey showed no resemblance to the typical morphology of Nevskia but did share a striking similarity among themselves in cell morphology, in the unusual appearance of colonies on various solid media and in various physiological properties. A full taxonomic analysis was performed, including DNA-DNA hybridization and nutritional screening with 117 organic compounds as sole sources of carbon and energy. The strains are active in the degradation of important environmental pollutants, and their phenotypic, physiological, metabolic and genomic properties suggest that they are members of a novel taxon in the gamma-Proteobacteria, for which the name Hydrocarboniphaga gen. nov. is proposed, with the single species Hydrocarboniphaga effusa sp. nov. The type strain is AP103T (=ATCC BAA-332T=DSM 16095T).