Most strains of Enterobacter sp. were classified as moderate biofilm producer. Conc

Biofilm Formation of Enterobacteragglomerans

erious gram-negative bacillary infections (especially those due to Pseudomonas aeruginosa) Aminoglycosides are active against most gram-negative aerobic and facultative anaerobic bacilli but lack activity against anaerobes and most gram-positive bacteria, except for most staphylococci; however, some gram-negative bacilli and methicillin-resistant staphylococci are resistant.

oglycosides (see Table: Aminoglycosides) have concentration-dependent bactericidal activity. They bind to the 30S ribosom

e inhibited by the dyes eosin and methylene blue added to the agar. Based on a moderate rate of lactose fermentation and acid production, Enterobacter species produces large, muco

e isolation of Enterobacter aerogenes grown

Large, yellow to salmon color

. A diffuse slime layer of variable thickness (the M antigen) also may be produced but, unlike the K antigens, it is nonspecific and is serologically cross-reactive among different organisms.

he outer membrane also contains lipopolysaccharide (LPS), of which the lipid A portion is endotoxic and the O (somatic) antigen is serotype specific.

Blood Agar 5%, TSA Agar, Nutrient Agar. For selective isolation: MacConkey Agar, Hektoen Enteric (HE) Agar, EMB Agar. For maintenance: Blood Agar 5%, TSA Agar, Nutrient Agar.

RECOMMENDED MEDIA

16-18 hours.

KEY BIOCHEMICAL REACTIONS

Facultatively anaerobic

20-30 degrees C

Spores: No.

Enterobacter species account for a small fraction of postsurgical endophthalmitis and posttraumatic cases. [18] Most ophthalmic infections are caused by gram-positive organisms, but Enterobacter species and Pseudomonas species are among the most aggressive pathogens.

Enterobacter cloacaeATCC 13047 Growth good to excellent; colonies medium-sized, deep blue, with or without violet halos

n ofNitroreductase(Phenotypic & genotypic detection)The results of nitrate reduction test revealed that , all isolates (100%) of Enterobacterwere able to red

URL:http://www.uokufa.edu.iq/journals/index.php/ajb/indexEmail: biomgzn.sci@uokufa.edu.iqISSN: 2073-8854Magazin of Al-Kufa University for Biology/ VOL.5/ NO.2 / year: 2013It was found low percentages of Enterobacterisolates (E. cloacae , E. sakazakii) are able to produce bacteriocin only against sensitive bacteria E.coli. This low production of bacteriocin may be due to siderophore production that can inhibit the activity of bacteriocin such receptor for the uptake siderophore also functions as receptor for the bacteriocin (cloacin)[18].Enterobacterbacteriocin were active against E.coli, but were inactive against Klebsiella pneumoniae, this may be due to the growth inhibitor products of the Enterobacter strains for typing are different in nature [18,24].-Production of RpoSA-Detection of rpoS gene in Enterobacterspp. by PCR.Twenty six isolates (31%) out of 84 isolates of Enterobacter

e( 1): Virulence factors of Enterobacterspeci

hemolysin and extracellular protease

ut all isolates of Enterobacterspecies had a polysaccharide capsule surrounding the bacterial cell except one isolate of E.cloacaethat lack capsule structure (98.8% versus 1.2%) [

wo species of Enterobacterwere grew efficiently on CHROMTMagar medium and yield

lass 1 fimbriae

eing able to chelate iron to survive and spread within the ho

hey produce acid upon glucose fermentation , methyl red negative ,

cter, and Serratia: Biochemical Differentiation and Susceptibility to Ampicillin and

Cephalosporins at 20 μg/ml or less inhibited 90% of the Klebsiella strains but only 15% of the Enterobacter strains. Ampicillin inhibited 27% of Enterobacter strains

R and VP tests are particularly useful in the identification of the Enterobacteriacea

erial keratitis is usually treated with antibiotic dr

Chemicals in water such as those used in swimming pools may irritate the cornea and weaken the delicate surface tissue of the cornea (corneal epithelium),

Fortunatelytheinfectionwascontrolledbytopicalsulphacetamideandgentamicindrops.Enterobactercloacaeisusuallyresistanttoampicillinandcanproduceacephalosporinasewhichmaydeactivatesomecephalosporins.'4Aminoglycosideshavebeenthemosteffectivedrugsagainsttheorganismandsepsishasbeentreatedwithcarbenicillinandanaminoglycoside.'H

nterobactercloacaewaspresentin4-12%ofallcasesofGram-negativebacteraemia.6I

terobacteriaceaesuchasKlebsiellacausecornealulceration.2AcaseofcornealulcerationduetoEnterobacterc

Book available

Antibiotic Susceptibility: Keratitis

On postoperative day 3, the organism was isolated to be an Enterobacter species, sensitive to ciprofl oxacin and gentamicin

Gram-negative organisms were found to be a rare cause of infectious keratitis, with only one case (due to Pseudomonas aeruginosa) in the literature. In an ASCRS survey of 338,550 LASIK pro-cedures, only 2 of 116 cases of infectious keratitis due to Gram-negative organisms were reported.

produce acid upon glucose fermentation, are methyl red negative, and Voges-Proskauer positive, with an optimal growth temperature of 30 °C(1). 80 % are encapsulated(1).

are susceptible to cefepime(7), aminoglycosides, fluoroquinolones, and trimethoprim-sulfamethoxazole(8). Tigecycline has been shown effective in vitro

Gram-negative bacilli, 0.6-1 μm in diameter and 1.2-3 μm long, motile by means of peritrichous flagella and have class 1 fimbriae

Enterobacter spp. are resistant to ampicillin; first- and second- generation cephalosporins(7); and cephalothin

Person to person transmission can occur through the fecal-oral route

Enterobacter spp. are commonly found in soil and water;

Proteus and Enterobacter are only present in a minority of humans [64].

The patient was treated topically with moxifloxacin (0.5%) and tobramycin (15 mg/ml) drops every hour and cyclopentolate 2% three times daily in the right eye. N-acetylcysteine eye drops were administered four times per day.

Gram-negative bacteria include opportunistic enterobac­teria (such as Serratia spp. and Klebsiella spp.) that can survive in contact lens fluid and on plastic surfaces, which explains their increased numbers in contact-lens-induced corneal infections.6

enterobac-teria (such asSerratia spp.andKlebsiella spp.) that can survive in contact lens fluid and onplastic surfaces, which explains their increased numbers incontact-lens-induced corneal infectio

CASE REPORTContact-lens-related corneal ulcer caused byklebsiella pneumoniae

Mechanisms of Pathogenicity

β-lactam antibiotics are bacteriocidal, and act by inhibiting the synthesis of the peptidoglycan layer of bacterial cell walls. The peptidoglycan layer is important for cell wall structural integrity, especially in Gram-positive organisms, being the outermost and primary component of the wall.

Beta-lactams: Carbapenems are the most reliable beta-lactam drugs for the treatment of severe Enterobacter infections; fourth-generation cephalosporins are a distant second choice Aminoglycosides: Aminoglycoside resistance is relatively common and varies widely among centers Fluoroquinolones: Resistance to fluoroquinolones is relatively rare but may be high in some parts of the world Trimethoprim-sulfamethoxazole (TMP-SMZ): Resistance to TMP-SMZ is more common

38°C or below 36°C

With few exceptions, the major classes of antibiotics used to manage infections with these bacteria include the beta-lactams, carbapenems, the fluoroquinolones, the aminoglycosides, and TMP-SMZ.

DRUG RESISTANCE: Enterobacter spp. are resistant to ampicillin; first- and second- generation cephalosporins(7); and cephalothin(6).

Plants(6), humans, and animals(1). Enterobacteriaceae are primarily colonizers of the lower gastrointestinal tract of humans and animals(10).

From 1970 to 1971, there was an epidemic of septicemia caused by contaminated IV products that affected 378 patients across the United States(9).

They produce acid upon glucose fermentation, are methyl red negative, and Voges-Proskauer positive, with an optimal growth temperature of 30 °C(1). 80 % are encapsulated(1).

Enterobacter spp. are commonly found in intensive care units and are responsible for 8.6 % of nosocomial infections according to the US Centers for Disease Control and Prevention

ENTEROBACTERIACEAE

multidrug-resistant Enterobacteriaceae (mostly Escherichia coli) that produce extended-spectrum β lactamases (ESBLs), such as the CTX-M enzymes, have emerged within the community setting as an important cause of UTIs.

Mechanisms of Beta Lactam Resistance in Enterobacter

Glucose fermentation and acid production Lactose and/or sucrose fermenta-tion and acid production GYellow with bubbles or cracksGas production from glucos

a painful red eye

poor final visual outcome

urease-variable.[2][3]