Shewanella putrefaciens keratitis in the lamellar bed 6 years after LASIK.

Using Kirby–Bauer method, it was sensitive to cefazoline, chloramphenicol, ciprofloxacin, gatifloxacin, moxifloxacin and ofloxacin.

Published literature on S. putrefaciens, has reported sensitivity to aminoglycosides, fluoroquinolones, third/fourth-generation cephalosporins, and resistance to penicillin.

Published literature on S. putrefaciens, has reported sensitivity to aminoglycosides, fluoroquinolones, third/fourth-generation cephalosporins,

resistance to penicillin.

These 24 isolates had the following profiles of resistance against 16 antibiotics: all the isolates were resistant to cephalothin and vancomycin and 95.8% were resistant to ampicillin.

For molecular biology experiments, S. putrefaciens strains were grown aerobically at room temperature (23 to 25°C) or at 30°C on Luria-Bertani (LB) medium, pH 7.4 (42)

Growth ConditionsTemperature: 30.0°CAtmosphere: Aerobic

most Shewanella infections are treated easily by a combination of surgical therapy/drainage and antibiotics

S. putrefaciensT (ATCC 8071)

The six cases involving S. putrefaciens were regarded as colonisations and were consequently not treated with specific antibiotics

eye infections [1,16].

S. algae and S. putrefaciens are non-fermentative bacilli with a single polar flagellum. They grow well on conventional solid media, including MacConkey agar, with 1–2-mm yellowish-brown colonies after incubation for 18–24 h.

An ability to form biofilms has been described in detail for Shewanella oneidensis and S. putrefaciens

all S. alga strains produced a hemolytic reaction on sheep blood agar while S. putrefaciens isolates lacked this activity.

Isolates that were motile, had oxidative metabolisms, were oxidase and catalase positive, ornithine decarboxylase positive, and DNase positive, and produced H2S on triple sugar iron slants within 72 h of incubation were identified as belonging to the phenospecies S. putrefaciens.

production of hydrogen sulfide gas (H2S) on TSI slants

S. alga causes the most human illnesses and that significant differences exist between these two species regarding resistance to antimicrobial agents, mouse pathogenicity, and certain virulence factors (hemolysis and adhesion).

Pathogenicity studies of mice indicate that S. alga appears to be the more virulent species, possibly due to the production of a hemolytic substance.

In contrast, Shewanella putrefaciens organisms (Gilardi biovars 1 and 3; CDC biotype 1) were more often associated with nonhuman sources (70%)

certain virulence factors (hemolysis and adhesion).

R-LPS without O-chains was described in S. putrefaciens (21, 28). The reduced lipopolysaccharide structure allows for better adhesion of bacteria to the iron-containing surface, and therefore more efficient use of this metal as an electron acceptor in respiration. The core of LPS has high concentrations of carboxyl and phosphoryl sites, which indicate the polarity, and contribute to the interaction with metal ions (21). In addition, the LPS of S. putrefacienspredisposes these bacteria to form biofilms on iron surface, and also enables to use this metal in their metabolic pathways.

solates of S. putrefacienshavethe ability to adhere to human epithelial type 2 cells(HEp-2) (20). Moreover, S. putrefaciensadhere and form biofilms on steel surfaces due to iron reduction (3). Bacterial adhesion ability is a significant problem in food industry, as it causes difficulties in their elimination from the production areas, adversely affects the quality of food, and may lead todiseases in humans. From the perspective of aquaculture, ability of S. putrefaciensto adhere to various tools and equipment at fish farms may be a source of fish infections. Since most bacterial fish pathogens, including S. putrefaciens, are facultative and may cause the diseases when environmental conditionsbecome unfavourable, it poses a serious problem

Another important property of the bacteria is secretion of cytolysins, e.g. haemolysins. Most strains of S. putrefaciensare not able to produce haemolysins (17, 24, 30); however, some isolates show this ability (20, 22, 36, 46), which indicates the diversity of these microorganisms.

Factors determining penetration and proliferation of S. putrefaciens, or tissue damage in the infected organisms have not been described yet. Therefore, potential virulence factors, which include enzymatic activity, cytotoxins secretion, adhesion ability, lipopolysaccharides (LPS), and the presence of siderophores, are analysed in this review.

It should be noted that S. putrefacienscould also be associated with different infections in humans, such as skin and tissue infections, bacteraemia, otitis. Investigations on pathogenic mechanisms of S. putrefaciensinfections are very limited. Enzymatic activity, cytotoxin secretion, adhesion ability, lipopolysaccharide (LPS), and the presence of siderophores are potential virulence factors of S. putrefaciens. Antimicrobial resistance of S. putrefaciensis different and depends on the isolates. In general, these bacteria are sensitive to antimicrobial drugs commonly used in aquaculture.

Important differential characteristics between the two species include the ability of S. algae to produce mucoid colonies with beta-hemolysis on sheep blood agar, grow at 42°C and in 6% NaCl (w/v), reduce nitrite, and an inability to produce acid from maltose, all of which are in contrast to the characteristics of S. putrefaciens.

Most Shewanella spp. isolates are susceptible to cefotaxime (95%), piperacillin and tazobactam (98%), gentamicin (99%), and ciprofloxacin (94%).

ear infection, or abdominal and biliary tract infections.

only known non-fermentative gram-negative rod that produces hydrogen sulfide

Shewanella putrefaciens has only been isolated from such clinical materials as various body wounds, feces, conjunctiva, urine, CSF, bile, ascitic fluid, pleural fluid, and stored blood. The major risk factor of S. putrefaciens infection is hepatobiliary disease, peripheral vascular disease, with chronic leg ulcer, poor hygiene, and socioeconomic status. In most cases, the bacteria reside in devitalized tissue or denuded skin and serve as a nidus for opportunistic infection. Soft tissue infections have various clinical manifestations including infected leg ulcer, cellulitis, abscess formation, and wound infection, which are often preceded by chronic ulceration of the lower limb, trauma, burn wound, and seawater exposure.

β-lactamase antibiotics

treated easily by a combination of surgical therapy, drainage and antibiotics.

Thus we tried to find out as to how many of Shewanella spp. are wrongly reported as Pseudomonas spp. by just doing simple biochemical tests over a period of six months.

soil and water being their natural habitat

oxidase and catalase-positive non-fermenter gram-negative rod that produces hydrogen sulfide.

foods, sewage, and both from fresh and salt water.

The rate of biofilm formation and the thickness of the film were not dependent on the availability of carbohydrate (lactate or glucose) or on iron starvation. The number of S. putrefaciens bacteria on the surface was partly influenced by the presence of other bacteria (Pseudomonas fluorescens) which reduced the numbers of S. putrefaciens bacteria in the biofilm. Numbers of bacteria on the surface must be quantified to evaluate the influence of environmental factors on adhesion and biofilm formation.

This Shewanella outbreak had a single-source origin and spread by contact transmission via a contaminated measuring cup. Shewanella species are emerging as potentially serious human pathogens in hospitals and could be included in hospital infection surveillance systems.

The estimated incubation period for Shewanella acquisition was 3-49 days

S. algae or S. putrefaciens was isolated from blood, for 9 (29.0%) of 31 patients who acquired one of the organisms; from bile, for 8 (25.8%), and from ascitic fluid, for 8 (25.8%). The attack rate of this outbreak was 5.8% (31 patients infected or colonized, of 534 potentially exposed on ward

and the pathogenicity of the two species together was 77.4% (24 patients infected, of 31 who acquired the pathogens)

To our knowledge, this is the first report of V. vulnificus andS. putrefaciens as causes of severe suppurative eye infection. Fortu-nately, this infection was limited to the eye.

Shewanella putrefaciens is as yet rarely responsible for clinical syndromes in humans

Nevertheless, S. putrefaciens also retains pathogenic potential, mainly under special environmental circumstances. Indeed, most of the reported infections pertained to contact with contaminated waters or injuries or occurrences in which integrity of the skin was compromised to some extent (3, 4, 9, 10, 12); this last issue encompasses also long-term catheters (1). In addition, isolation of S. putrefaciens occurred in polymicrobial infections (3).

Both S. putrefaciens and Shewanella alga are uncommon as isolates from clinical syndromes, their natural habitats being all forms of water, fish, oily foodstuffs, and soils (2, 4, 11)

We report 16 cases of S. putrefaciens infection that occurred at the Veterans General Hospital-Kaohsiung in Taiwan between 1990 and 1995. S. putrefaciens infection was associated with a wide clinical spectrum including bacteremia/septicemia, skin and soft-tissue infection, biliary tract infection, peritonitis, and empyema.

hydrogen sulfide on TSI.[

On blood agar plates, the colonies are typically convex and large, with a brown pigment, and cause “greening” of the agar around the colonies.

bright pink color. On solid media, the colonies are round, fast-growing, and pink.

facultative anaerobe

marine environments