Phenol degradation and genotypic analysis of dioxygenase genes in bacteria isolated from sediments

Abstract The aerobic degradation of aromatic compounds by bacteria is performed by dioxygenases. To show some characteristic patterns of the dioxygenase genotype and its degradation specificities, twenty-nine gram-negative bacterial cultures were obtained from sediment contaminated with phenolic compounds in Wuhan, China. The isolates were phylogenetically diverse and belonged to 10 genera. All 29 gram-negative bacteria were able to utilize phenol, m-dihydroxybenzene and 2-hydroxybenzoic acid as the sole carbon sources, and members of the three primary genera Pseudomonas, Acinetobacter and Alcaligenes were able to grow in the presence of multiple monoaromatic compounds. PCR and DNA sequence analysis were used to detect dioxygenase genes coding for catechol 1,2-dioxygenase, catechol 2,3-dioxygenase and protocatechuate 3,4-dioxygenase. The results showed that there are 4 genotypes; most strains are either PNP (catechol 1,2-dioxygenase gene is positive, catechol 2,3-dioxygenase gene is negative, protocatechuate 3,4-dioxygenase gene is positive) or PNN (catechol 1,2-dioxygenase gene is positive, catechol 2,3-dioxygenase gene is negative, protocatechuate 3,4-dioxygenase gene is negative). The strains with two dioxygenase genes can usually grow on many more aromatic compounds than strains with one dioxygenase gene. Degradation experiments using a mixed culture representing four bacterial genotypes resulted in the rapid degradation of phenol. Determinations of substrate utilization and phenol degradation revealed their affiliations through dioxygenase genotype data.

Persistent Bordetella petrii Infection Related to Bone Fractures

No abstract available.

Computational fluid dynamics simulation of different impeller combinations in high viscosity fermentation and its application / 生物工程学报

Agitator is one of the essential factors to realize high efficient fermentation for high aerobic and viscous microorganisms, and the influence of different impeller combination on the fermentation process is very important. Welan gum is a microbial exopolysaccharide produced by Alcaligenes sp. under high aerobic and high viscos conditions. Computational fluid dynamics (CFD) numerical simulation was used for analyzing the distribution of velocity, shear rate and gas holdup in the welan fermentation reactor under six different impeller combinations. The best three combinations of impellers were applied to the fermentation of welan. By analyzing the fermentation performance, the MB-4-6 combination had better effect on dissolved oxygen and velocity. The content of welan was increased by 13%. Furthermore, the viscosity of production were also increased.

A Skin Ulceration Complicated by Alcaligenes Xylosoxidans Infection

A. xylosoxidans infection can result in potentially severe sequelae, especially in unhealthy populations. We present a rare case of infectious skin ulceration with scar contracture due to A. xylosoxidans in a healthy patient. A 53-year-old male patient without underlying disease and trauma history visited our department for an irritating skin ulcer with purulent discharge on the right lower leg. The chronic wound on the leg exists since he got contact burn 30 years ago. The wound did not respond to treatment, and the wound culture results indicated A. xylosoxidans. Given the incurable character of A. xylosoxidans, we performed a wide excision and split thickness skin graft with collagen-elastin matrix (Matriderm(R)). A. xylosoxidans is an opportunistic, aerobic, gram-negative, rod-shaped bacterium that is oxidase positive. According to reports, A. xylosoxidans is not sensitive to many antibiotics and can cause bacteremia. It is suggested that the blood supply is compromised near a scar lesion despite the fact that blood flow is rather increased during the initial scar formation phase. Therefore, we presumed that the infection was most likely caused by low blood circulation due to scar contracture. Thus, when a scar contracture is present, A. xylosoxidans infection can manifest in a healthy patient.

Infección respiratoria causada por Alcaligenes xylosoxidans en un paciente con síndrome de Mounier-Kuhn / Case report: respiratory infection due to Alcaligenes xylosoxidans in a patient with Mounier-Kuhn syndrome

Mounier-Kuhn syndrome is a rare entity characterized by abnormal dilatation of the trachea and main bronchi (tracheobronchomegaly). Alcaligenes xylosoxidans is a non fermenting gram-negative pathogen common in extra-and intra-hospital environment, which may be related to immunosuppression states. We describe the case of a 75 years old male, ex-smoker with moderate functional obstruction, chronic respiratory failure and chronic colonization by Pseudomonas aeuriginosa. He had an infectious exacerbation of his disease, reason that previously required several hospital admissions. The patient was treated with antibiotics and his evolution was favourable with negativization in cultures of the pathogen. This is the first description of the isolation of Alcaligenes xylosoxidans as a cause of respiratory infection in a patient with Mounier-Kuhn syndrome.

A Case of Alcaligenes xylosoxidans Keratitis in a Soft Contact Lens Wearer

PURPOSE: To report a case of corneal ulcer due to Alcaligenes xylosoxidans in a soft contact lens wearer. CASE SUMMARY: A 20-year-old female patient presented with a corneal ulcer. The patient had been wearing soft contact lenses over 6 months. The ulcer had a typical appearance, similar to that of immune infiltration due to contact lenses. However, the corneal scraping and culture yielded Alcaligenes xylosoxidans, which is susceptible to ceftazidime and levofloxacine in the antibiotic susceptibility test. After treatment with topical antibiotics, her eye improved, with only a mild corneal scar remaining. CONCLUSIONS: Alcaligenes xylosoxidans should be considered as a potential causal pathogen of keratitis upon wearing soft contact lenses. Additionally, any lesion should be suspected as a bacterial corneal ulcer, even if appearing as an immune infiltration due to contact lenses.

A Case of Corneal Ulcer by Alcaligenes Faecalis

PURPOSE: To report a case of corneal ulcer due to Alcaligenes faecalis in a patient with a preexisting corneal ulcer. CASE SUMMARY: A 58-year-old male patient presented with a corneal ulcer without a history of any trauma. The patient had a history of corneal ulcer 9 months earlier. The patient had previously been diagnosed with diabetic retinopathy and neovascular glaucoma, and his visual acuity was no light perception. Corneal scraping and culture yielded Alcaligenes faecalis susceptible to most antibiotics in the antibiotic susceptibility test. After treatment with empirical systemic antibiotics and eyedrops, his eye improved with a remaining corneal scar. CONCLUSIONS: Alcaligenes faecalis should be considered as a causal pathogen of corneal ulcer in patients with suspicious compromised ocular surface, such as previous corneal ulcer.

Isolation and preliminary characterization of a o-nitrobenzaldehyde-degrading Alcaligenes sp. ND1 / Isolamento e caracterização preliminar de lcaligenes SP ND1 degradador de o-nitrobenzaldeido

This paper reports the isolation and characterization of a new o-nitrobenzaldehyde (ONBA)-degrading bacterium, Alcaligenes sp. ND1. ND1 degraded almost all ONBA (100 mg L-1) in M9 medium within 36 hours. The key enzyme(s) involved in the initial biodegradation was a constitutively intracellular enzyme(s). This bacterium has great potential utility for bioremediation.

Esse trabalho relata o isolamento e a caracterização de uma nova bactéria degradadora de o-nitrobenzaldeido (ONBA), Alcaligenes sp ND1. A bactéria ND1 decompôs todo o ONBA (100 mg.L-1) do meio M9 em 36 horas. A enzima-chave envolvida na biodegradação inicial foi uma enzima constitutiva intracelular. Esta bactéria apresenta um potencial de aplicação para bioremediação.

Postoperative Alcaligenes xylosoxidans endophthalmitis: report of two cases

We report two cases of postoperative Alcaligenes xylosoxidans endophthalmitis. A 78-year-old woman in good general health developed A. xylosoxidans endophthalmitis one month after an uncomplicated phacoemulsification procedure with posterior chamber intraocular lens. It was performed on her left eye, at another institution. Removal of the intraocular lens and capsule was performed because of recurrent inflammation after vitrectomy and intravitreal antibiotic injections. Her son, a 55-year-old man, developed A. xylosoxidans endophthalmitis in his left eye, two months after an uncomplicated phacoemulsification procedure with posterior chamber intraocular lens (it also was performed by the same surgeon). He also required vitrectomy with removal of the intraocular lens and capsule because of persistent disease. A. xyloso - xidans can cause chronic low-grade and progressive endophthalmitis after cataract extraction that is often resistant to corrective antibiotic therapy. This kind of case is rare. There have been only previously reported seven cases worldwide to the best of our knowledge.

Relatamos dois casos de endoftalmite pós-operatória causada por Alcaligenes xylosoxidans. Uma mulher de 78 anos de idade e saúde geral boa desenvolveu endoftalmite por A. xylosoxidans um mês após ser submetida a facoemulsificação com implante de lente intra-ocular de câmara posterior, sem complicações. A cirurgia foi realizada no olho esquerdo em outra instituição. A remoção da lente e da cápsula intra-ocular foi realizada em conseqüência da inflamação recorrente após vitrectomia e injeções intravítreas de antibiótico. Seu filho, de 55 anos, desenvolveu endoftalmite por A. xylosoxidans, no olho esquerdo, dois meses após facoemulsificação com implante de lente intra-ocular de câmara posterior (realizada também pelo mesmo cirurgião). Foi necessária também realização de vitrectomia com remoção da lente intra-ocular e da cápsula posterior em função da doença persistente. A. xyloso - xidans pode causar a endoftalmite crônica, branda e progressiva após a extração da catarata e é freqüentemente resistente à terapia antibiótica. Este tipo de caso é raro. De acordo com nosso conhecimento, existem apenas sete casos relatados previamente.

A case of lethal kwashiorkor caused by feeding only with cereal grains / 소아과

Kwashiorkor is a syndrome of severe protein malnutrition, which manifests itself in hypoalbuminemia, diarrhea, dermatitis, and edema. It can be life-threatening due to associated immune deficiency and an increased susceptibility to infections. Kwashiorkor should be treated early with nutritional support and the control of infection. Dilated cardiomyopathy may develop during the treatment and in such cases a poor prognosis is expected. Kwashiorkor has been known as a common disease of poor countries. To date, in fact, there has been no report of kwashiorkor leading to death in technically advanced countries. We here report a fatal case of a baby girl admitted with kwashiorkor. She had been fed only with cereal grain mixed with juice, without any protein supplement, for 2 months. This diet was deficient not because of poverty, but due to the illiteracy of her parents. The patient suffered from diarrhea, whole body edema, hypothermia, and dermatitis. Laboratory findings revealed an immune-deficient state featuring leukopenia and decreased immunoglobulin. Blood and urine cultures revealed Alcaligenes Xylosoxidans growth. The patient was fed frequent small amounts of protein-containing formula and intravenous albumin and micronutrients were administered for nutritional support. She was also treated with intravenous immunoglobulin and antibiotics in order to control infection. Nevertheless, she developed dilated cardiomyopathy and multi-organ failure and died. We review this case in light of the literature.

Meningitis caused by Alcaligenes xylosoxidans in a patient with HIV/AIDS

The purpose of the present work was to inform about the first case of meningitis associated to the bacteria Alcaligenes xylosoxidans in a patient with HIV/AIDS. The patient was a 46-year-old male, with the antecedent of have been diagnosed for HIV/ AIDS, who attended in the Hospital Universitario de Colima, Mexico, with fever, shock and meningismus. The study of the cerebrospinal fluid showed pleocytosis, elevated protein levels and hypoglycorrhachia. The culture yielded the presence of Alcaligenes xylosoxidans with sensitivity to ciprofloxacin. After 14 days of treatment with this antibiotic, the patient showed neurologic improvement and was able to continue with his outpatient antiretroviral treatment. The present case shows the importance of the inclusion of this bacterium in the differential diagnosis of the neurological infections in HIV/AIDS patients and emphasizes the importance of considering the bacterial meningitis in this population.

Antibacterial and toxicological evaluation of beta-lactams synthesized by immobilized beta-lactamase-free penicillin amidase produced by Alcaligenes sp.

Search for anti-beta-lactamase and synthesis of newer penicillin were suggested to overcome resistance to penicillin in chemotherapy. It was found that clavulanic acid, an ant-beta-lactamase was ineffective due to its structural modification by bacteria. Thus, there is a need for the synthesis of newer pencillins. Retro-synthesis was inspired by the success of forward reaction i.e.conversion of penicillin G to 6-aminopenicillanic acid (6-APA) by biological process. In the present study a better enzymatic method of synthesis of newer pencillin by a beta-lactamase-free penicillin amidase produced by Alcaligenes sp. is attempted. Antibacterial and toxicological evaluation of the enzymatically synthesized beta-lactams are reported. Condensation of 6-APA with acyl donor was found to be effective when the reaction is run in dimethyl formamide (DMF 50% v/v) in acetate buffer (25 mM pH 5.0) at 37 degrees C. Periplasm entrapped in calcium alginate exihibited the highest yield (approximately 34%) in synthesis. The minimum inhibitory concentration of the synthetic products against Staphylococcus aureus and Salmonella typhi varied between 20-80 microg/ml. Some of the products exhibited antibacterial activity against enteric pathogens. It was interesting to note that product A was potent like penicillin G. LD50 value of three products (product A, B and C) was more than 12 mg/kg. Furthermore, these synthetic beta-lactams did not exihibit any adverse effect on house keeping enzymes viz., serum glutamate oxalacetate-trans-aminase, serum glutamate pyruvate -trans-aminase, acid phosphatase, alkaline phosphatase of the test animals. The hematological profile (RBC and WBC) of the test animals also remained unaffected.

Bacteremia in pediatric cancer patients: A single center study / 소아과

PURPOSE: Bacteremia is one of the major concerns in the treatment of pediatric cancer patients. This study was to determine the etiologic agents and the pattern of antibiotic susceptibilities in a single tertiary medical center. METHODS: We retrospectively reviewed the medical records of the cases of bacteremia in pediatric cancer patients from 1998 to 2005 in Keimyung University Dongsan Medical Center. RESULTS: There were 62 cases of bacteremia from 44 patients. Gram-positive organisms(48.3%) were more common than gram-negative organisms(38.7%) or fungi(13%). Among gram-positive organisms, Staphylococcus epidermidis was the most common etiologic agent(63.3%), followed by Staphylococcus aureus(16.7%), alpha-hemolytic Streptococcus(16.7%), and Streptococcus mitis(3.3%). Among gram-negative organisms, Alcaligenes xylosoxidans was the most common agent(41.7%) and the other organisms were Klebsiella pneumoniae(20.8%), Stenotrophomonas maltophilia(12.5%), Acinetobacter baumanii(8.2%), etc. In febrile neutropenic patients, however, K. pneumoniae was the most common cause of gram-negative bacteremia. All of the isolated K. pneumoniae in our center produced extended-spectrum beta-lactamase and were related with high mortality. S. aureus, S. epidermidis, and Streptococcus species were all susceptible to vancomycin and teicoplanin. Most staphylococci were resistant to penicillin and oxacillin. Most of the gram-negative organisms were susceptible to imipenem. CONCLUSION: Gram-positive organisms were more commonly isolated than gram-negative organisms in pediatric cancer patients like other studies. We could obtained valuable information on the choice of proper antibiotics in our institution. Further studies will be needed to explain the prevalence of A. xylosoxidans in our center.

A Case of Alcaligenes xylosoxidans Endophthalmitis after Cataract Extraction

PURPOSE: To report a case of Alcaligenes xylosoxidans endophthalmitis following cataract extraction and IOL implantation. In Korea, Alcaligenes xylosoxidans endophthalmitis has not been reported. METHODS: The patient was transferred for endophthalmitis at 6 days after cataract extraction and IOL implantation. Alcaligenes xylosoxidans was founded in culture. We performed pars plana vitrectomy with removal of IOL and lens capsule, and then we supplied systemic IV antibiotics with fortified topical antibiotics. RESULTS: Sixty-four days after vitrectomy, corrected visual acuity was 1.0 and anterior segment showed no inflammatory cell.

Optimization of technological conditions for one-pot synthesis of (S)-alpha-cyano-3-phenoxybenzyl acetate in organic media / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Optically active form of alpha-cyano-3-phenoxybenzyl (CPB) alcohol, building block of pyrethroid insecticides, was synthesized as its acetate by the combination of anion-exchange resin (D301)-catalyzed transcyanation between m-phenoxybenzaldehyde (m-PBA) and acetone cyanohydrin (AC), and lipase (from Alcaligenes sp.)-catalyzed enantioselective transesterification of the resulting cyanohydrin with vinyl acetate. Through optimizing technological conditions, the catalyzing efficiency was improved considerably compared to methods previously reported. Concentrations of CPB acetate were determined by gas chromatograph. The enantio excess (e.e.) values of CPB acetate were measured by NMR (nuclear magnetic resonance) method. Effects of solvents and temperatures on this reaction were studied. Cyclohexane was shown to be the best solvent among the three tested solvents. 55 degrees C was the optimal temperature for higher degree of conversion. External diffusion limitation was excluded by raising the rotational speed to 220 r/min. However, internal diffusion could not be ignored, since the catalyst (lipase) was an immobilized enzyme and its particle dimension was not made small enough. The reaction rate was substantially accelerated when the reactant (m-PBA) concentration was as high as 249 mmol/L, but decreased when the initial concentration of m-PBA reached to 277 mmol/L. It was also found that the catalyzing capability of recovered lipase was high enough to use several batches. Study of the mole ratio of AC to m-PBA showed that 2:1 was the best choice. The strategy of adding base catalyst D301 was found to be an important factor in improving the degree of conversion of the reaction from 20% to 80%. The highest degree of conversion of the reaction has reached up to 80%.

Microbial dehalogenation of polychlorinated biphenyls in aerobic conditions / Dehalogenación microbiana de bifenilos policlorados en condiciones aeróbicas

From soils contaminated with polychlorinated biphenils (PCBs) a strain of Alcaligenes sp. able to grow in a mineral medium with a commercial mixture of PCBs as carbon source was isolated. This strain consumed up to 200 ppm in seven days in laboratory conditions. After 24 h of incubation, some new congeners of PCBs could be recognized by mass spectrometry. Through the identification of these compounds it was possible to postulate examples of possible transformations by dechlorinations of penta- and tetra-chlorinated congeners into tri-chlorinated ones. The properties of the isolated strain are appropriate for bioremediation of contaminated areas and also for using in bioreactors in order to remove the xenobiotic chemical.

A partir de suelos contaminados con bifenilos policlorados (PCBs) se aisló una cepa de Alcaligenes sp. capaz de crecer en medio mineral con una mezcla comercial de PCBs como fuente de carbono. Esta cepa consumió hasta 200 ppm de PCBs en siete días de incubación en condiciones de laboratorio. En 24 horas de incubación se han podido detectar nuevos congéneres de PCBs mediante espectrometria de masa. La identificación de estos compuestos ha permitido postular transformaciones de congéneres penta- y tetra-clorados que originarían derivados triclorados. Las propiedades de la cepa aislada son apropiadas para biorremediación y para su uso en biorreactores para eliminar estos compuestos xenobióticos.

Biological control of Fusarium wilt of pigeonpea Cajanus cajan (L.) Millsp with chitinolytic Alcaligenes xylosoxydans.

Alcaligenes xylosoxydans protected pigeonpea from Fusarium wilt in a pot experiment and field trials. When seeds of pigeonpea (C. cajan) were treated with A. xylosoxydans and sown in soil infested with Fusarium, the incidence of wilt was reduced by 43.5% and resulted in 58% higher grain yield. The antifungal activity of A. xylosoxydans was based on chitinase production and was comparable in efficacy to commercial antifungal agents such as benlate, monitor WP, thiram and bavistin.

A Pseudoepidemic of Alcaligenes xylosoxidans Due to Contaminated Buffer Solution / 병원감염관리

Background: A clinician reported unusually high incidence of A. xylosoxidans isolation from aspirated tissues in outpatient clinic. Methods: A. xylosoxidans isolates from January 2002 to June 2002 were investigated. The infection control nurse reviewed medical records and observed the procedures of tissue aspiration and culture at the clinical microbiology laboratory. Specimens were obtained for investigational cultures from dye, aspiration gun, slide alcohol sponge, tray, sink. water of sink, buffer solution, microscope, computer, and telephone. Results: A. xyloxosidans was isolated from twenty-four patients during 6 months. None of 24 cases had any typical signs or symptoms of infections by A. xylosoxidans. Observation of tissue aspiration and culture procedure revealed that buffer solution was used for prevention of specimen drying after tissue aspiration. Culture of the buffer solution yielded a heavy growth of A. xylosoxidans from four out of ten specimens. A. xylosoxidans was not isolated from any other investigational specimens. Conclusions: This was supposed to represent pseudoepidemic. Contaminated buffer solution was documented as the cause of this pseudoepidemic. The usage of buffer solution was stopped. During the follow-up period of 2 months, no additional A. Xylosoxidans was cultured from aspirated tissues.