Irfan Erol

Serotype distribution of Salmonella isolates from turkey ground meat and meat parts.

The aim of the study was to find out the serotype distribution of 169 Salmonella colonies recovered from 112 Salmonella positive ground turkey (115 colonies) and 52 turkey meat parts (54 colonies). Out of 15 Salmonella serotypes: S. Corvallis, S. Kentucky, S. Bredeney, S. Virchow, S. Saintpaul and S. Agona were identified as the predominant serovars at the rates of 27%, 13%, 12%, 12%, 11%, and 10%, respectively. Other serotypes were below 6% of the total isolates. All S. Kentucky and S. Virchow and most of the S. Corvallis (39/46) and S. Heidelberg (9/9) serotypes were recovered from ground turkey. The results indicate that turkey ground meat and meat parts were contaminated with quite distinct Salmonella serotypes. This is the first study reporting Salmonella serotype distribution in turkey meat and S. Corvallis as predominant serotype in poultry meat in Turkey.

Prevalence and molecular characterization of sorbitol fermenting and non-fermenting Escherichia coli O157:H7(+)/H7(-) isolated from cattle at slaughterhouse and slaughterhouse wastewater.

The prevalence and seasonal distribution of E. coli O157:H7(+)/H7(-) in an array of aged cattle at slaughter and its dissemination with slaughterhouse wastewater over a two year period in Turkey were investigated. For this purpose, a total of 720 samples (240 rectoanal mucosal swap [RAMS], 240 carcass sponge and 240 bile samples) of 240 cattle categorized according to age, gender, breed and sampling site were collected along with additional 24 wastewater samples and were subjected to immunomagnetic separation based cultivation technique to efficiently isolate E. coli O157 from the background flora. Identification (rfbEO157, fliCh7), detection of major virulence factors (stx1, stx2, eaeA, hly, lpfA1-3 and espA), intimin variants (eae-α1, eae-α2, eae-β, eae-β1, eae-β2, eae-γ1 and eae-γ2/θ) and shiga toxin variants (stx1c, stx1d, stx2c, stx2d, stx2e, stx2f and stx2g) of all the isolates were assessed by PCR. From 10 (4.2%) of RAMS and 11 (4.6%) of carcass sponge samples and 5 (20.8%) of slaughterhouse wastewater samples, a total of 102 colonies (99 sorbitol negative and 3 sorbitol positive) were isolated. Overall, 17 (7.1%) and 15 (6.3%) of 240 sampled cattle were shown to harbor E. coli O157 and E. coli O157:H7, respectively either in their RAMS or carcass sponge samples analyzed. Statistically significant differences between categories; season, age, gender and breed of cattle were not observed (p>0.05). None of the isolated E. coli O157:H7(+)/H7(-) strains harbored any of the investigated intimin types other than eaeγ1 or shiga toxin variants stx1d, stx2e, stx2f or stx2g while all were lpfA1-3(+) except 5 E. coli O157:H7(-) strains. Intimin variant eaeγ1 and shiga toxin 1 variant stx1c were detected from all of the eaeA(+) (97/102, 95.1%) and stx1(+) (32/102, 31.3%) strains, respectively while from stx2(+) (80/102, 78.4%) isolates, both stx2c (68/80, 85.0%) and stx2d (12/80, 15.0%) variants were determined. In the last decade, prevalence of E. coli O157:H7 has an increasing trend in cattle. Slaughterhouses are the significant sources of environmental contamination with E. coli O157:H7. Isolation and molecular characterization of sorbitol fermenting E. coli O157:H7 are a novel finding and may lead to a revision of reference isolation procedure of E. coli O157:H7 in future.

Immunomagnetic separation and PCR detection of Listeria monocytogenes in turkey meat and antibiotic resistance of the isolates

1. Conventional cultivation and immunomagnetic separation (IMS) cultivation methods were compared for the isolation specificity and sensitivity of L. monocytogenes from turkey meat samples. PCR was used to confirm the isolates. Disc diffusion was performed to determine the antibiotic susceptibility profiles. A total of 180 turkey meat samples collected from markets in Turkey were tested. 2. L. monocytogenes was detected in 23 samples (12·7%) by IMS and conventional cultivation. It was isolated from 16·6% (10/60), 11·6% (7/60) and 10·0% (6/60) of the meat cut, breast and leg samples, respectively. PCR assay was performed based on hlyA (LLO-listeriolysin O) gene specific primers. In all 23 (100·0%) isolates of the hlyA gene were determined. The disc diffusion test showed that 19 (82·6%) isolates were resistant to penicillin G and 17 (73·9%) to ampicillin. In addition, 8 isolates were partially resistant to erythromycin and 8 to streptomycin. 3. In conclusion, to safeguard public health turkey meat must be produced under hygienic and suitable technological conditions. Furthermore antimicrobials, as prophylactic or growth promoter agents, must be firmly controlled by governmental agencies.

Relation between Serotype Distribution and Antibiotic Resistance Profiles of Listeria monocytogenes Isolated from Ground Turkey

The objectives of this study were to determine the serotype distribution of Listeria monocytogenes isolated from ground turkey using a multiplex PCR assay and to determine antimicrobial resistance profiles of the isolates using the disc diffusion method. Of 78 isolates, 35 (44.9%), 29 (37.2%), 7 (9.0%), and 7 (9.0%) were identified as serotypes 1/2a (or 3a), 4b (or 4d or 4e), 1/2b (or 3b), and 1/2c (or 3c), respectively. Overall, 63 isolates (80.8%) were resistant to penicillin G, and 53 (67.9%) were resistant to ampicillin. All 1/2c (or 3c) serotype isolates were resistant to penicillin G and ampicillin, and all 1/2b (or 3b) serotype isolates were resistant to penicillin G. In addition, 91.4% (32 of 35) of 1/2a (or 3a), 57.1% (4 of 7) of 1/2b (or 3b), and 37.9% (11 of 29) of 4b (or 4d or 4e) serotype isolates were resistant to ampicillin, and 85.7% (30 of 35) of 1/2a (or 3a) and 65.5% (19 of 29) of 4b (or 4d or 4e) serotype isolates were resistant to penicillin G. In conclusion, most of the L. monocytogenes isolates identified were serotype 1/2a (or 3a) and 4b (or 4d or 4e). Serotype 1/2c (or 3c) isolates were highly resistant to antibiotics compared with isolates of serotypes 1/2a (or 3a), 1/2b (or 3b), and 4b (or 4d or 4e). Increasing resistance of L. monocytogenes to ampicillin and penicillin is an especially serious concern for public health because of the common use of these antibiotics in treatment of human listeriosis cases.

Molecular typing of Clostridium perfringens isolated from turkey meat by multiplex PCR

Aims:  To determine the presence of toxin genes in 22 Clostridium perfringens isolated from turkey meat samples by molecular typing.

Incidence and antibiotic resistance of Salmonella spp. in ground turkey meat

1. The objectives of this study were to isolate Salmonella spp. by conventional culture technique from ground turkey samples, to determine the seasonal distribution of Salmonella spp., to verify the isolates by PCR using primers based on oriC gene sequence, and to determine the antibiotic susceptibility profiles of the isolates. A total of 240 packaged fresh ground turkey samples marketed in Ankara were analysed between July 2004 and June 2005. 2. One hundred and ten out of 240 (45⋅8%) samples were positive for Salmonella spp. and confirmed by PCR. The distribution of Salmonella spp. was determined as 48⋅3, 55⋅0, 63⋅3 and 16⋅6%, during spring, summer, autumn and winter, respectively. Statistical analysis showed a significant difference for the prevalence of Salmonella spp. between winter and the other seasons. 3. Of the isolates, 54 out of 110 (49⋅0%) were resistant to one or more antibiotics tested. The highest resistance was observed to nalidixic acid (25⋅4%), followed by streptomycin (17⋅2%) and tetracycline (15⋅4%). 4. In conclusion, this is a disturbing finding, both for the high prevalence of Salmonella and the extent of antibiotic resistance. Ground turkey should be produced under suitable hygienic and technological conditions and the use of antimicrobials must be controlled by governmental agencies to protect public health from salmonellosis and from the consequences of increased resistance to the antibiotics.

H-NS controls metabolism and stress tolerance in Escherichia coli O157:H7 that influence mouse passage

BackgroundH-NS is a DNA-binding protein with central roles in gene regulation and nucleoid structuring in Escherichia coli. There are over 60 genes that are influenced by H-NS many of which are involved in metabolism. To determine the significance of H-NS-regulated genes in metabolism and stress tolerance, an hns mutant of E. coli O157:H7 was generated (hns::nptI, FRIK47001P) and its growth, metabolism, and gastrointestinal passage compared to the parent strain (43895) and strain FRIK47001P harboring pSC0061 which contains a functional hns and 90-bp upstream of the open-reading frame.ResultsThe hns mutant grew slower and was non-motile in comparison to the parent strain. Carbon and nitrogen metabolism was significantly altered in the hns mutant, which was incapable of utilizing 42 carbon, and 19 nitrogen sources that the parent strain metabolized. Among the non-metabolized substrates were several amino acids, organic acids, and key metabolic intermediates (i.e., pyruvate) that limit carbon acquisition and energy generation. Growth studies determined that the parent strain grew in LB containing 14 to 15% bile or bile salts, while the hns mutant grew in 6.5 and 9% of these compounds, respectively. Conversely, log-phase cells of the hns mutant were significantly (p < 0.05) more acid tolerant than the parent strain and hns mutant complemented with pSC0061. In mouse passage studies, the parent strain was recovered at a higher frequency (p < 0.01) than the hns mutant regardless of whether log- or stationary-phase phase cells were orally administered.ConclusionThese results demonstrate that H-NS is a powerful regulator of carbon and nitrogen metabolism as well as tolerance to bile salts. It is likely that the metabolic impairments and/or the reduced bile tolerance of the E. coli O157:H7 hns mutant decreased its ability to survive passage through mice. Collectively, these results expand the influence of H-NS on carbon and nitrogen metabolism and highlight its role in the ability of O157:H7 strains to respond to changing nutrients and conditions encountered in the environment and its hosts.

Prevalence and Characterization of Salmonella Isolated from Chicken Meat in Turkey

This study was conducted in a Turkish province to investigate the presence of Salmonella spp. in 150 chicken meat samples using 2 phenotyping techniques: classic culture technique (CCT) and immunomagnetic separation (IMS). For the confirmation of the isolates at molecular levels, invA gene was detected in these isolates. The presence of invA, class 1 (Cls1) integrons, and integrase (Int1) genes was demonstrated by PCR assay; and the resistance of the isolated Salmonella spp. strains to antibiotics was determined by disk diffusion test. All the cultural and PCR results were evaluated together; Salmonella spp. were detected in a total of 64 (42.66%) chicken meat samples. Contamination rate was higher in carcasses (53.33%, n = 75) than in meat pieces (32%, n = 75). When results of standard culture were compared with IMS technique, IMS (n = 54) showed a clear superiority over the CCT (n = 38). A very high resistance rate (≥ 89.28%) to vancomycin, tetracycline, streptomycin, or nalidixic acid was found. Trimethoprim-sulfamethoxazole resistance was present in 32.14%. Relatively lower incidence of resistance (≤ 8.33%) to gentamicin, chloramphenicol, ampicillin, and ceftriaxone was observed. Concurrent resistance to at least 4 antibiotics was detected in 92.85% of the isolates. Cls1 integrons and Int1 were positive in 80.95% and 95.23% of the isolates, respectively. However, Int1 alone was detected in 15.47% (n = 13). In conclusion, the high prevalence of Salmonella spp. in chicken meat may pose a potential public health risk, and the presence of antibiotic-resistant Salmonella spp. isolate together with Cls1 integron and/or integrase might play an important role in horizontal antibiotic gene transfer.

Isolation and genomic characterization of Escherichia coli O157:H7 in bile of cattle

A total of 200 bile samples of cattle collected from two slaughterhouses from May to September 2007 were analyzed by immunomagnetic separation (IMS)-based cultivation technique. Two (1.0%) of the samples were found to be contaminated with E. coli O157:H7. One of the two isolates was found to carry all five virulence genes (fliCh7, stx1, stx2, eaeA and hly), and the other isolate was positive for these genes except stx2 by multiplex PCR. According to the PFGE, the strains isolated from two different bile samples displayed different XbaI REDP. Antibiotic susceptibility profiles indicated that two isolates were resistant to cephalothin and intermediately resistant to ampicillin, streptomycin and sulphamethoxazole. Also, one isolate was intermediately resistant to kanamycin. It is concluded that the gallbladder should be considered as a possible site and source of E. coli O157:H7 in cattle.

Antibiotic resistance of Escherichia coli O157:H7 isolated from cattle and sheep

A total of 102 Escherichia coli O157:H7 colonies recovered from 11 cattle and 14 sheep were collected and tested for their antibiotic resistance profiles using a disc diffusion method, according to the Clinical and Laboratory Standards Institute. Four (36.36 %) of the 11 cattle E. coli O157:H7 isolates were resistant to cephalothin, one (9.09 %) isolate was resistant to streptomycin, and one (9.09 %) to nalidixic acid. Two (14.28 %) of the 14 sheep E. coli O157:H7 isolates were resistant to sulphamethoxazole, one (7.14 %) isolate was resistant to sulphonamide compounds, and one (7.14 %) to streptomycin. All cattle and sheep isolates were found to be susceptible to cephazolin, gentamicin, ciprofloxacin, imipenem, trimethoprim/ sulphamethoxazole, chloramphenicol, trimethoprim, and ceftiofur. Six cattle isolates were susceptible at a ratio of 54.54 %, and 11 (78.57 %) isolates from sheep were susceptible to all 20 antibiotics tested. As an overall result, 68 % of the E. coli O157:H7 isolates belonging to cattle and sheep were susceptible to all antibiotics tested. On the other hand, most of the E. coli O157:H7 isolates were intermediately resistant to streptomycin, cephalothin, sulphamethoxazole, ampicillin, and kanamycin.