Acute cellulitis with Shewanella algae bacteremia

ABSTRACT Shewanella algae are gram-negative bacteria commonly found in aquatic environments. Infections caused by this agent are rarely documented; however, they are increasingly reported, mainly in countries with warm to temperate climates. Herein, we present a case of a 46-year-old immunocompetent woman with acute cellulitis and S. algae bacteremia (the first isolation culture performed at our hospital). To better understand the epidemiology, clinical outcomes, and treatment possibilities for S. algae bacteremia, we searched literature for similar cases; however, we did not find any cases of infections caused by this microorganism reported in Portugal or the Azores.

Advances in electrochemically active biofilm of Shewanella oneidensis MR-1 / 生物工程学报

Facing the increasingly severe energy shortage and environmental pollution, electrocatalytic processes using electroactive microorganisms provide a new alternative for achieving environmental-friendly production. Because of its unique respiratory mode and electron transfer ability, Shewanella oneidensis MR-1 has been widely used in the fields of microbial fuel cell, bioelectrosynthesis of value-added chemicals, metal waste treatment and environmental remediation system. The electrochemically active biofilm of S. oneidensis MR-1 is an excellent carrier for transferring the electrons of the electroactive microorganisms. The formation of electrochemically active biofilm is a dynamic and complex process, which is affected by many factors, such as electrode materials, culture conditions, strains and their metabolism. The electrochemically active biofilm plays a very important role in enhancing bacterial environmental stress resistance, improving nutrient uptake and electron transfer efficiency. This paper reviewed the formation process, influencing factors and applications of S. oneidensis MR-1 biofilm in bio-energy, bioremediation and biosensing, with the aim to facilitate and expand its further application.

Enhanced heterologous expression of the cytochrome c from uncultured anaerobic methanotrophic archaea / 生物工程学报

Cytochrome c is a type of heme proteins that are widely distributed in living organisms. It consists of heme and apocytochrome c, and has potential applications in bioelectronics, biomedicine and pollutant degradation. However, heterologous overexpression of cytochrome c is still challenging. To date, expression of the cytochrome c from uncultured anaerobic methanotrophic archaea has not been reported, and nothing is known about the function of this cytochrome c. A his tagged cytochrome c was successfully expressed in E. coli by introducing a thrombin at the N-terminus of CytC4 and co-expressing CcmABCDEFGH, which is responsible for the maturation of cytochrome c. Shewanella oneidensis, which naturally has enzymes for cytochrome c maturation, was then used as a host to further increase the expression of CytC4. Indeed, a significantly higher expression of CytC4 was achieved in S. oneidensis when compared with in E. coli. The successful heterologous overexpression of CytC4 will facilitate the exploitation of its physiological functions and biotechnological applications.

Biogenic synthesis of selenium nanoparticles by Shewanella sp. HN-41 using a modified bioelectrochemical system

BACKGROUND Synthesis of selenium nanoparticles from selenite by Shewanella sp. HN-41 demonstrated that particle size depended on the reaction time and biomass of cells. The slow reaction and low biomass tended to form small particles. In this study, Shewanella sp. HN-41 was introduced into the anode of a nonexternal circuit bioelectrochemical system (nec_BES) to convert chemical energy from lactate to low electron current to the cathode, where selenite was reduced. RESULTS Our experiment with two systems, one bioelectrochemical system with a cathode flushed with nitrogen and the other with a no-nitrogen-flushing cathode, showed that the former could not produce Se nanoparticles after 21 d, but the latter formed them with an average size of 37.7 nm. The SEM and TEM images demonstrated that the particle size of 10 nm occupied over 10% and most of the particles were in the range of 30­60 nm. The XRD result and SAED image demonstrated no clear peaks of crystal and proved that the Se nanoparticles are amorphous. CONCLUSIONS : The clean Se nanoparticles were synthesized and completely separated from bacterial cells in the bioelectrochemical system. This study opened a new approach for the biological synthesis of metal nanoparticles. Finally, the Se products in the range of 30­60 nm can be tested for antimicrobial activities in medical applications

Shewanella algae keratitis

A 75-year-old male with a right eye history of chronic dry eye syndrome, glaucoma status post tube shunt, and Fuchs dystrophy status post Descemet stripping endothelial keratoplasty followed by penetrating keratoplasty (PKP) presented with a 2.7 × 4.2 mm corneal ulcer, culture positive for Shewanella algae and Klebsiella oxytoca. A topical antibiotic regimen of gentamicin 14 mg/mL and vancomycin 50 mg/mL was administered according to culture sensitivities. There was concurrent use of loteprednol 0.5% (Lotemax Gel, Bausch and Lomb, Rochester, NY, USA) and later addition of erythromycin 0.5% ointment. The corneal ulcer improved with antibiotic therapy but was complicated by poor patient follow-up. Descemetocele formation prompted PKP in the right eye. The graft was successful and visual acuity improved from a low of light perception to maximum of 20/200 Snellen.

Infectious Keratitis Caused by Shewanella Putrefaciens

PURPOSE: We report a case of infectious keratitis caused by Shewanella putrefaciens in a patient after fishing. CASE SUMMARY: A 75-year-old male with no underlying disease other than hypertension was admitted to our hospital because of decreased visual acuity and congestion in his left eye for 2 weeks. At the first ophthalmic examination, the best-corrected visual acuity (BCVA) of the left eye was counting fingers. Slit lamp examination showed stromal infiltrates with 2.0 × 2.0 mm corneal epithelial defects, endothelial inflammatory plaques and 1 mm height hypopyon with severe inflammation in the anterior chamber. Bacterial culture tests were performed by corneal scraping, which were positive for Shewanella putrefaciens, followed by treatment with moxifloxacin and ceftazidime topical antibiotics. After 2 months of treatment, the BCVA of the left eye improved to 0.4 and the corneal lesion clinically improved with residual mild stromal opacity. CONCLUSIONS: Shewanella putrefaciens should be considered as a causal pathogen of infectious keratitis in patients after fishing. We report a case of infectious keratitis caused by Shewanella putrefaciens, which has never previously been reported in the Republic of Korea.

Marine bacteria from the Gulf of California with antimicrofouling activity against colonizing bacteria and microalgae / Bacterias marinas del Golfo de California con actividad antimicrobiana frente a bacterias colonizadoras y microalgas

Abstract One way of reducing the input of pollutants into the marine environment is to enforce the use of non-toxic antifouling paints in marine protected areas. Thus, the purpose of this study was to detect marine microorganisms that secrete inhibitory substances against bacteria and microalgae to avoid biofouling on manmade structures in La Paz bay, B.C.S., Mexico. The inhibitory potential of 125 bacteria was evaluated against biofilm-forming bacteria. Crude extracts were obtained with methanol and ethyl acetate from 16 bacterial strains that exhibited antagonistic and antibacterial activity in a preliminary screening. Antibacterial and antimicroalgal assays were performed using crude extracts, the minimum inhibitory concentration (MIC) was determined. The highest activity against bacteria and microalgae was found in two strains, Shewanella algae and Staphylococcus sp. The results of this study suggest that extracts of bacteria from the Gulf of California with antimicrobial properties against biofilm-forming bacteria can also prevent the adhesion of microalgae, which may control the development of biofilm formation and, as a consequence, biofouling.(AU)

Resumen Una alternativa para reducir la contaminación en el medio marino es el uso de pinturas anti-incrustantes no tóxicas en áreas marinas protegidas. En el presente estudio se propuso encontrar microorganismos marinos que secreten sustancias capaces de inhibir la adhesión de bacterias y microalgas, de esta manera evitar la bioincrustación en estructuras marinas en la bahía de La Paz, B.C.S., México. Un total de 125 bacterias fueron evaluadas por su capacidad para inhibir el desarrollo de bacterias formadoras de biopelículas. En una selección preliminar de actividad antagónica y antibacteriana, 16 cepas bacterianas mostraron potencial actividad inhibitoria, de las que se obtuvieron los extractos crudos con metanol y acetato de etilo. Se realizaron ensayos antibacterianos y anti-microalgales utilizando los extractos crudos, se determinó la concentración mínima inhibitoria (MIC). Dos cepas mostraron la mayor actividad contra bacterias y microalgas: Shewanella algae y Staphylococcus sp. Los resultados de este estudio sugieren que los extractos de bacterias aisladas en el Golfo de California que poseen propiedades antimicrobianas contra las bacterias formadoras de biofilm y también pueden prevenir la adhesión de microalgas, con lo que se podría controlar el desarrollo de la formación de biopelículas y como consecuencia, el biofouling.(AU)

Seudoquiste pancreático infectado por Shewanella putrefaciens: reporte de caso / Pancreatic pseudocyst infected by Shewanella putrefaciens: A case report

Shewanella putrefaciens es un bacilo gramnegativo, no fermentador, oxidasa positivo, productor de sulfato de hidrógeno, que de manera inusual causa cuadros infecciosos en humanos. Este germen oportunista produce infecciones en pacientes inmunosuprimidos y/o con antecedente de exposición a comida o agua de mar contaminados con el germen. A continuación presentamos un reporte de caso de un paciente con una infección del páncreas por este germen.

Shewanella putrefaciens is a rare Gram-negative bacillus, non-fermenting, oxidasepositive, and a hydrogen sulfide producer, which infrequently causes human infections. This opportunist germ causes infections in immunosuppressed people and in those with a history of contact with seawater or food contaminated with the microbe. We present a case of a patient with a pancreatic infection caused by this microbe.

Shewanella putrefaciens infective endocarditis

Shewanella putrefaciens rarely causes infection in humans. In the last few decades a growing number of cases have been described. The following report outlines the case of a 40-year- old immunocompetent white man with S. putrefaciens infective endocarditis. This is the first known case of infective endocarditis due to an apparently monomicrobial S. putrefaciens infection, and the second known case of S. putrefaciens-related infective endocarditis worldwide.

A Case of Spontaneous Bacterial Peritonitis with Bacteremia Caused by Shewanella algae / 감염과화학요법

Human infection caused by Shewanella algae is rare, which usually occurred after direct contact with seawater or ingestion of raw seafood in the immunocompromised host. There have been anecdotal reports about Shewanella infections in human, but their pathogenic role and microbiologic data are limited. Here, we report a fatal case of spontaneous bacterial peritonitis with bacteremia due to S. algae in a 57-year-old male with liver cirrhosis who had no history of exposure to seawater or raw seafood. Polymicrobial infection with Streptococcus mitis and Escherichia coli was combined and the patient died in spite of early appropriate antimicrobial therapy and early goal-directed therapy for sepsis.

Shewanella Dysentery in a Patient with Underlying Malignancy

Shewanella spp is a facultatively anaerobic, motile, gramnegative bacillus and can be found throughout the world mainly in marine environments and soil. It is a rare pathogen in human and infection by it is usually associated with underlying severe morbidities. We report a case of a 69- years old woman who presented with Shewanella putrefaciens dysentery and who was subsequently found to have underlying malignancy.

Isolation and characterization of a novel bacterial strain Shewanella marinisediminis sp. nov. from deep-sea sediments.

A new bacterial strain designated DH39T was isolated from marine sediment collected from the East Sea, Korea. Phylogenetic analysis using the 16S rRNA gene sequence revealed that strain DH39T clustered with the genus Shewanella and is closely related to Shewanella canadensis HAW-EB2T, S. woodyi MS32T, and S. sediminis HAW-EB3Twith 98.1, 97.8, and 97.6% sequence similarities, respectively. The isolated bacterium was Gram-negative, rod-shaped, and aerobic. Its temperature range for growth was 4–30°C. The predominant fatty acids were 16:1w7, 17:1w8, 13:0-i, 16:0, and 15:0-i. The DNA G+C content was 45.0 mol%. DNA-DNA hybridization analysis showed that DNA-DNA relatedness values in the 16S rRNA phylogenetic tree of strain DH39T and its nearest neighbors S. hanedai and S. sediminis were 52.9 and 58.7%. Phylogenetic evidence and phenotypic characteristics suggest strain DH39T constitutes a novel Shewanella species. Therefore, we propose Shewanella marinisediminis sp. nov., with DH39T (KCCM 42936T = NCCB 100311T) as the type strain.

A Case of Endophthalmitis Caused by Shewanella algae after Trauma

PURPOSE: To report a rare case of endophthalmitis caused by Shewanella algae after trauma. CASE SUMMARY: A 27-year-old man was referred for trauma caused by a fishing sinker in his right eye. On initial examination at another hospital, his visual acuity was light perception, and intraocular pressure was 50 mm Hg. On slit lamp examination, corneal edema and severe anterior chamber inflammation were observed. Consequently, the next day total pars plana vitrectomy, lensectomy, intravitreal silicone oil injection, and antibiotics injection were performed. After the operation, intraocular pressure was 15 mm Hg and the patient's pain was temporarily decreased. The presence of Shewanella algae in the vitreous culture was determined but antibiotic sensitivity was not proven. The patient received postoperative topical fortified vancomycin, ceftazidime, and tobramycin hourly and underwent intravenous antibiotic therapy. On postoperative day 25, the patient transferred to our hospital and ocular pain presented continuously. Intraocular inflammation was not severe but visual acuity was light perception because of retinal necrosis in the posterior pole. Therefore, the patient received topical fortified antibiotics and intravenous antibiotics therapy. On postoperative month 2, visual acuity was light perception and the patient's right eye progressed to pthisis bulbi. CONCLUSIONS: Here in the first case reported in Korea or other conturies of primary endophthalmitis by Shewanella algae after traumas. Shewanella algae endophthalmitis has a rapid progression and poor visual prognosis in spite of aggressive therapy.

A Case of Shewanella algae Bacteremia Accompanying Cellulitis in Both Legs of a Patient on Hemodialysis: Case Report and Literature Review / 감염과화학요법

We report a fatal case of Shewanella algae bacteremia accompanied by cellulitis in both legs of a chronic renal failure patient who had not been exposed to sea water or raw fish. A 47-year-old male on hemodialysis was admitted to our clinic due to pain in both legs accompanied by a febrile sensation that started 2 days prior to his visit. A blood culture specimen revealed S. algae, a rare human opportunistic pathogen. In spite of early and appropriate antimicrobial treatment, the patient died of septic shock on the second day of his hospital stay. Recently, serious infections caused by Shewanella species have been reported in increasing frequency. Hepatobiliary diseases have been proposed as predisposing factors, not only for infection by this organism, but also for fatality. However, we should be aware of the significance of S. algae in patients with renal insufficiency, especially those on maintenance hemodialysis. Herein, we report our case with review relevant literature.

Shewanella infection of snake bites: a twelve-year retrospective study

OBJECTIVE: Infections of snake bite wounds by Shewanella are rarely discussed in the medical literature. This study aims to characterize the presentation and management of Shewanella infections in snake bite wounds. METHOD: We retrospectively investigated the microbiology, clinical features, and outcomes of patients with Shewanella infected snake bite wounds admitted to a tertiary medical center from January 1998 to December 2009. RESULTS: Ten patients with Shewanella-infected snake bite wounds were identified. All of the snake bites were caused by cobras. The majority of patients had moderate to severe local envenomation and polymicrobial infections. Shewanella isolates are susceptible to ampicillin-sulbactam, piperacillin-tazobactam, third-and fourthgeneration cephalosporins, carbapenems, aminoglycosides, and quinolones but are resistant to penicillin and cefazolin. All of the patients examined had favorable outcomes. CONCLUSION: It is recommended that Shewanella infection be considered in snake bite patients, especially when patients present with moderate to severe local envenomation.

Isolation of Shewanella algae from rectal swabs of patients with bloody diarrhoea.

Shewanella algae is an emerging bacteria rarely implicated as a human pathogen. It was infrequently recovered from clinical specimens probably because of inadequate processing of non-fermenting oxidase-positive gram-negative bacilli. We report here isolation of S. algae in pure culture and mixed with E. coli from two cases of acute gastroenteritis with bloody mucous containing diarrhea occurring at the same time. As this organism is not a normal flora of the gut, the possible source of infection may be fish contaminated with the organism. Whether this bacterium can be considered an enteric pathogen needs to be evaluated. The cases were clinically diagnosed as acute bacillary dysentery. The bacterium was identified by 16S r-RNA gene sequence analysis.

Detection of a new qnrA7 genotypes in Shewanella algae / 中华微生物学和免疫学杂志

Objective To research the distribution and the characteristics of the plasmid mediated quinolone resistant genes in Shewanella algae. Methods The qnr, qepA, aac(6')-Ib-cr genes were amplified by PCR, then the positive PCR products were sequenced to determine the gene type. The transferability of plasmid mediated quinolone resistance was ensured by conjugation experiment. MICs were measured by E-test. qnrA gene was mapped to plasmids to locate it. Results The qnrA gene were detected in the Shewanella algae, this is a newfound subgroup qnrA7, the GenBank accession no. was GQ463707, qnrB, qnrS,qnrC, qnrD, qepA and aac(6')-Ib-cr genes were not detected. qnrA7 reside in a plasmid about 33 kb, conjugation experiment was unsuccessful. The strain was susceptible to quinolones. Conclusion It deserves paying close attention to the report of an original qnrA subgroup in an isolate of water-borne species of Shewanella algae.

Shewanella algae en un paciente con diarrea crónica: primer caso en Costa Rica / Shewanella algae in a patient with chronic diarrhea: first case in Costa Rica

Se presenta el caso de un paciente masculino, vecino de Pavas-San José, con historia de diarrea crónica. En el coprocultivo se identificó shewanella algae. Casos de infección en humanos por esta bacteria son raros y se han encontrado, predominantemente localizadas, en piel, oídos y tejidos blandos con o sin bacteremia, en la mayoría de los cuales existe el antecedente de contacto con ambientes marinos. Shewanella algae es sensible a aminoglicósidos, carbapanemes, eritromicina y quinolonas, pero resistente a penicilinas. La sensibilidad a ampicilina y cefalosporinas es variable. Nuestro paciente fue tratado con cefalexina y tuvo una respuesta satisfactoria al mismo, con cese de los síntomas. De acuerdo con nuestro conocimiento este el primer caso documentado, en Costa Rica, de infección gastrointestinal por esta bacteria.

We report herein the case of a male patient, from Pavas, San Jose, with chronic diarrhea whose stool culture grew Shewanella algae. Infections caused by this micro-organism are infrequent and most commonly involve ears, skin and soft tissue, with or without bacteremia and are usually linked to ocean contact in warm climate countries. Shewanella algae is sensitive to aminoglycosides, carbapenems, erythromycin and quinolones, but resistant to penicillin. Sensitivity to amplicilin and cephalosporins is variable. Our patient was treated withcefalexin, with satisfactory results. To our knowledge, this is the first documented case in Costa Rica of gastrointestinal infection caused by this microorganism.

Primary Shewanella algae Bacteremia Mimicking Vibrio Septicemia

Shewanella algae infections are rare in humans. Previously reported cases of S. algae have mainly been associated with direct contact with seawater. We report a case of primary S. algae bacteremia occurring after the ingestion of raw seafood in a patient with liver cirrhosis that presented a fulminent course of necrotizing fasciitis.

Isolation and characterization of Shewanella spp.from patients of food poisoning / 中华流行病学杂志

Objective To identify the isolates of Shewanella spp.from specimens of food poisoning based on biological and biochemical analysis.Methods Strains were obtained from the investigation on two food poisoning episodes in September and October,2007 in Ma'anshan city,Anhui province.In accordance with the national standard protocol(GB/T 4789),all specimens were enriched and isolated on selective medium,and the suspected strains were ldentified by the VITEK-32 and API20E systems.For Shewanella spp.identified by the biochemical system,more characteristics were analyzed using auxiliary biochemical,growth,hemolytic and drug-resistance tests.DNAs of Shewanella spp.were extracted,16S rDNA was PCR amplified and sequenced with universal 16S rDNA primers.Phylogenetic tree was constructed with MEGA 4.0.Results After enrichment, all specimens were inoculated to selective medium and Shewanella spp.strains were isolated from 8 samples with single colony on both TCBS and BP media.The characteristics of growth in the Triple Sugar Iron (TSI) agar appeared to have had hydrogen sulfide production but no gas production or positive oxidase.No Shewanella spp.strain was detected in WS,SS and EMB media.The 8 strains were identified as Shewanella algae(S.algae) or Shewanella putrefaciens(S.putrefaciens) by VITEK-32,as S.putrefaciens by API20E system.No other enteropathogenic bacteria,including Vibrio cholerae,Salmonella,Vibrio parahaemolyticus,Proteus vulgaris or Staphylococcus aureua,were detected from those 8 samples.From 16S rDNA phylogenetic trees,7 out of 8 ShewaneUa spp.were identified as S.algae.1 as S.putrefaeiens.Conclusion Strains of Shewanella spp.were lsolated from samples of the food poisoning episodes,providing a possible clue to investigate the role of Shewanella spp.on food poisoning