Genotypic characterization of fluoroquinolone-resistant Escherichia coli isolates from edible offal

Abstract: Edible offal is easily contaminated by Escherichia coli (E. coli) and fluoroquinolone (FQ)-resistant E. coli is considered a serious public health problem, thus, this study investigated the genetic characteristics of FQ-resistant E. coli from edible offal. A total of 22 FQ-resistant E. coli isolates were tested. A double mutation in each gyrA and parC led the highest MIC. Four (18.2%) isolates carried plasmid-mediated quinolone resistance genes. The fimH, eaeA, escV, astA, and iucC genes were confirmed. Seventeen isolates (77.3%) were positive for plasmid replicons. The isolates showed high genetic heterogeneity based on pulsed-field gel electrophoresis patterns.

Inhibitory effect of Suaeda asparagoides (Miq.) extract on the motility of rat gastric antrum is mediated by beta-adrenoceptor / 한국실험동물학회지

Suaeda asparagoides (Miq.) has long been used as a Korean folk herbal medicine for the treatment of functional gastrointestinal disorders. However, reports on its pharmacological activity on gastrointestinal motility are scarce. The present study investigated the effects of Suaeda asparagoides water fraction of the extract (SAWF) on antral motility in vitro. Muscle strips from rat gastric antrum were set up in an organ bath in a circular orientation. SAWF (100 microg/mL) inhibited the spontaneous contraction of antral circular muscle strips. These inhibitory effects were not significantly affected by tetrodotoxin (1 microM), N omega-Nitro-L-arginine methyl ester hydrochloride (100 microM), 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one (10 microM), ryanodine (10 microM) and phentolamine (10 microM). SAWF-induced inhibition was mostly restored by cyclopiazonic acid (10 microM). Furthermore, the beta-adrenergic receptor antagonist, propranolol (10 microM), abolished SAWF-induced inhibition. These results suggest that SAWF may exert its activity on gastrointestinal smooth muscle via a-adrenergic receptors and sarcoplasmic reticulum Ca2+ ATPase.

Inhibitory Effects of Korean Red Ginseng Extract on Atopic Dermatitis in NC/Nga Mice / 한국실험동물학회지

Atopic dermatitis (AD) is a chronic eczematous skin disease attended by pruritus, erythema, edema, excoriation, and dryness. This study was to evaluate the effects of Korean red ginseng (RG) on AD in NC/Nga mice treated with 1-chloro-2,4,6-trinitrobenzene (picryl chloride; PC). Experimental groups were divided into 4 groups; normal control (NC), PC control, and PC-RG (50 and 100 mg/kg). RG was orally administered every day repeatedly during 6 weeks. The skin lesions in severity score, scratching behavior, serum immunoglobulin E (IgE), interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) levels, and histological appearance were examined. AD-like lesions were developed on the NC/Nga mice by topical PC applications. Oral administration of RG (50 and 100 mg/kg) significantly suppressed the development of AD, as analyzed by a modified SCORAD score. The scratching behavior decreased after RG administration. The levels of serum IgE, IL-4 and IFN-gamma were increased by PC stimulation, but treatment with RG (100 mg/kg) suppressed the increment of the serum IgE, IL-4 and IFN-gamma levels. Histologically, RG inhibited dermatitis lesions such as hypertrophy, hyperkeratosis, and infiltration of inflammatory cells into epidermis and dermis. These results suggest that the administration of RG may be effective in alleviating the AD induced by PC.

Inhibitory Effects of Korean Red Ginseng Extract on Atopic Dermatitis in NC/Nga Mice / 한국실험동물학회지

Atopic dermatitis (AD) is a chronic eczematous skin disease attended by pruritus, erythema, edema, excoriation, and dryness. This study was to evaluate the effects of Korean red ginseng (RG) on AD in NC/Nga mice treated with 1-chloro-2,4,6-trinitrobenzene (picryl chloride; PC). Experimental groups were divided into 4 groups; normal control (NC), PC control, and PC-RG (50 and 100 mg/kg). RG was orally administered every day repeatedly during 6 weeks. The skin lesions in severity score, scratching behavior, serum immunoglobulin E (IgE), interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) levels, and histological appearance were examined. AD-like lesions were developed on the NC/Nga mice by topical PC applications. Oral administration of RG (50 and 100 mg/kg) significantly suppressed the development of AD, as analyzed by a modified SCORAD score. The scratching behavior decreased after RG administration. The levels of serum IgE, IL-4 and IFN-gamma were increased by PC stimulation, but treatment with RG (100 mg/kg) suppressed the increment of the serum IgE, IL-4 and IFN-gamma levels. Histologically, RG inhibited dermatitis lesions such as hypertrophy, hyperkeratosis, and infiltration of inflammatory cells into epidermis and dermis. These results suggest that the administration of RG may be effective in alleviating the AD induced by PC.

Analysis of Salmonella enterica serotype Enteritidis isolated from human and chickens by repetitive sequence-PCR fingerprinting, antibiotic resistance and plasmid profiles

A total of 22 Salmonella enterica serotype Enteritidis (S. Enteritidis) strains isolated from human and chicken were subjected to DNA fingerprinting by repetitive sequence PCR using ERIC and BOX primers, antibiotic resistance and plasmid patterns. Both ERIC and BOX PCR amplification data revealed a highly genetic homogeneity between isolates from human and chicken except one isolate, which originated from chicken and showed a different DNA band pattern from others. Eleven of 22 S. Enteritidis isolates (50%) were resistant to more than one antibiotics and characterized by 5 resistance patterns. The most common pattern was penicillin resistant (63.6%). Only one isolate from chicken showed a multiple drug resistance patterns to 4 antibiotics. All 22 S. Enteritidis isolates harbored more than two plasmids with eight different plasmid profiles including two to six plasmids with approximate molecular size ranging from 1.9 to 21 kb. A band of 15 kb size was detected in all isolates tested, however, the band sizes smaller than 15 kb were found only in isolates from chicken.

Simultaneous detection of Lawsonia intracellularis, Brachyspira hyodysenteriae and Salmonella spp. in swine intestinal specimens by multiplex polymerase chain reaction

A multiplex PCR assay was developed for the simultaneous detection of the etiologic agents associated with porcine proliferative enteropathies (PPE), swine dysentery (SD)and porcine salmonellosis (PS)in a single reaction using DNA from swine intestinal samples. Single and multiplex PCR amplification of DNA from Lawsonia intracellularis, Salmonella typhimurium and Brachyspira hyodysenteriae with each primer set produced fragments of the predicted size without any nonspecific amplification, 210-bp, 298-bp and 403-bp bands, respectively. The single PCR assay could detect as little as 100 pg of purified DNA of S. typhimurium and L. intracellularis, and 50 pg of B.hyodysenteriae, respectively. However, multiplex PCR turned out to be 10 times lower sensitivity with S. typhimurium compared with single PCR. With 23 swine intestinal specimens suspected of having PPE, SD and/or PS, the multiplex PCR assay showed identical results with conventional methods except one. In conclusion, this multiplex PCR is a feasible alternative to standard diagnostic methods for detection of L. intracellularis, B. hyodysenteriae and Salmonella spp. from swine intestinal specimens.

Prevalence of Lawsonia intracellularis, Brachyspira hyodysenteriae and Salmonella in swine herds

The prevalence of Lawsonia intracellularis, Brachyspira hyodysenteriae and Salmonella spp. were investigated by multiplex PCR using fecal samples of pigs with diarrhea or a history of diarrhea. The overall herd prevalence of L. intracellularis, B. hyodysenteriae and Salmonella spp. were 46.5%, 37.2% and 51.1%, respectively. Also, the prevalence of L. intracellularis, B. hyodysenteriae and Salmonella spp. among all sampled pigs were 19.9%, 10.8% and 17.7%, respectively. Seventeen of 43 herds were positive with 2 enteric organisms, and 2 herds were positive with L. intracellularis, B. hyodysenteriae and Salmonella spp. simultaneously. It was notable that 11 of 12 herds with more than 2, 000 pigs were affected with Salmonella spp., and that only 2 of 12 the herds were affected with B. hyodysenteriae. This study suggested that herds positive for L. intracellularis, B. hyodysenteriae and Salmonella spp. were distributed throughout Korea, although the relationship among other pathogens such as viral or parasitic ones and/or with metabolic disorders was not determined.

Detection of Lawsonia intracellularis in diagnostic specimens by one-step PCR

Lawsonia intracellularis is not culturable with a standard bacteriologic culture. One step PCR assay as a clinical diagnostic method was developed for the rapid detection of porcine proliferative enteritis (PPE) caused by L. intracellularis. Primers were designed based on the p78 DNA clone of L. intracellularis. The one step PCR resulted in the formation of a specific 210-bp DNA product derived from L. intracellularis. The nonspecific amplification product was not detected with swine genomic DNA or other bacterial strains causing similar symptoms to L. intracellularis infection. The one step PCR was as sensitive as 100 pg of L. intracellularis genomic DNA. We applied this method to field specimens diagnosed as PPE by macroscopic observation. Of 17 mucosal scraping specimens, 16(94%) were identified as positive to PPE and 15(88%) of 17 feces specimens. These results suggest that the one step PCR can be used as a rapid diagnostic method for L. intracellularis infection.