[Serotype distribution and antimicrobial susceptibilities of Salmonella strains recovered from environmental samples between 2008-2014]. / 2008-2014 yillari arasinda çevresel örneklerden izole edilen Salmonella suslarinin serotip dagilimi ve antimikrobiyal duyarliliklari.

Despite the measures taken and control applications worldwide, Salmonella infections continue to threat the public health. Since these infections also cause significant economical loss, the salmonellas continue to be forefront globally. The determination of Salmonella serotypes and their sources is important for epidemiological point of view. In this study, serotype distribution and antimicrobial resistance of environmental isolates of Salmonella spp. recovered from the poultry farms, that were send for confirmation and serotyping between seven years period, 2008-2014, were evaluated. Strains isolated from environmental samples that were sent to Public Health Institute, Department of Microbiology Reference Laboratory, National Reference Laboratory for Enteric Pathogens, were inoculated onto Salmonella-Shigella and Xylose Lysine Desoxycholate agar and evaluated after 18-24 hours of incubation at 37°C. The identification of the strains was performed by using standard biochemical tests from the suspected colonies. Strains compatible with Salmonella spp. were serotyped using polyvalent and monovalent Salmonella O and H antisera by slide agglutination method. Antibiotic susceptibility tests were performed and evaluated according to CLSI recommendation using Kirby-Bauer disk diffusion method. In our study, a total of 2011 Salmonella strains were evaluated and 15 different serogroups and 75 different serotypes were identified. The most common Salmonella serotypes were S.Infantis (30.6%), followed by S.Enteritidis (21.8%), S.Typhimurium (6.5%), S.Kottbus (5.2%), S.Tennessee (4.3%), S.Mbandaka (4.1%), S.Indiana (3.9%), S.Kentucky (3%), S.Corvallis (2.5%), S.Paratyphi B (1.9%) and S.Hadar (1.7%). Among the isolates, 50.1% (1008/2011) were found susceptible to all of the tested antimicrobials. The rate of isolates that were resistant to only one drug was found to be 15.6%, whereas 30.9% of the strains showed multi-drug resistance (resistant to ≥ 3 antimicrobial drugs). Antimicrobial resistance rates of the Salmonella strains were as follows; nalidixic acid 35.9%, tetracycline 30%, sulfonamides 27.5%, trimethoprim 25.6%, trimethoprim/sulfamethoxazole 25.4%, streptomycin 23.4% and ampicillin 13.5%, respectively. The highest resistance rates for streptomycin (91.4%) ampicillin (88.6%) and tetracycline (88.6%) were observed in S.Hadar strains; for sulfonamide (82.2%) and trimethoprim/sulfamethoxazole (78.2%) in S.Infantis strains, and for nalidixic acid in S.Indiana (97.4%), S.Hadar (91.4%) and S.Infantis (88.8%) strains. In conclusion, the origins, serotypes and antibiotic susceptibility patterns of the strains should be defined for the management of Salmonella infections which are still today a global problem.

Characterization of Shiga Toxin-Producing Escherichia coli Isolated from Humans between 2011 and 2014.

Although E. coli O157:H7 is the major serotype among Shiga toxin-producing Escherichia coli (STEC) strains, non-O157 serotypes have caused numerous outbreaks worldwide. We aimed to evaluate the distribution of serogroups, serotypes, virulence genes, and antimicrobial resistance of STEC strains recovered from stool samples. A total of 395 stool samples characterized by watery/bloody diarrhea and/or symptoms of hemolytic-uremic syndrome were included in this study. Strains compatible with E. coli, based on biochemical tests, were tested for the presence of Shiga toxin by ELISA. Toxigenic strains were tested by serotyping and serogrouping. Virulence genes, stx1, stx2, aggR, hlyA, and eae were detected by polymerase chain reaction. Overall, 26 (6.6%) stool culture samples tested positive for STEC. Shiga toxin was positive in 28 (7.1%) patient isolates based on ELISA and PCR. Two isolates could not be serotyped. STEC strains were distributed into 10 serogroups and 14 serotypes. Of the serotyped strains, 92.3% were non-O157, with the major distribution in O104:H4 and O26:HNM. All were negative for extended-spectrum ß-lactamase enzyme and 62.5% were resistant to at least 1 drug. This study demonstrated the wide distribution of non-O157 STEC strains from our patient group. Further studies should be performed to better understand STEC characteristics on a larger scale.

[Bacteremia caused by ciprofloxacin-resistant Salmonella serotype Kentucky: a case report and the review of literature]. / Siprofloksasine dirençli Salmonella serotip Kentucky bakteriyemisi: Olgu sunumu ve literatürün gözden geçirilmesi.

Salmonella infections can be seen in four clinical types, namely gastroenteritis, bacteremia/sepsis, enteric fever and carriage. These infections can result in uncomplicated diarrhea in most cases, but can lead to invasive disease requiring antimicrobial therapy and can be life-threatening in elderly or immunocomprimised patients. Broad-spectrum cephalosporins and fluoroquinolones are crucial options in the treatment of the invasive infections. Ciprofloxacin resistance is rarely seen in non-typhoid Salmonella enterica isolates, and only in S. Typhimurium, S. Choleraesuis and S. Schwarzengrund. In this report, we aimed to discuss a patient infected with ciprofloxacin-resistant Salmonella Kentucky under the light of data from our country and the world. A 52-year-old male patient wih acute myocardial infarction was hospitalized in intensive care unit of cardiovasculer surgery for left ventricular assist device (LVAD) implantation for the treatment of left ventricular disfunction. On the seventh day of LVAD and coronary artery bypass grafting (CABG), the patient presented high fever and productive cough. His physical examination revealed hyperemia around the insertion point of right jugular central venous catheter (CVC) and a serous discharge from the insertion point of LVAD located just below the inferior edge of sternum. Empiric IV cefoperazone/sulbactam (SCF) therapy was started with the prediagnosis of pneumonia and bloodstream infection. The blood samples taken from peripheral veins and CVC, and swabs taken from LVAD insertion point for culture when the patient was febrile, revealed the growth of bacteria with S type and lactose-negative colonies on EMB and SS media. Biochemical characteristics of the isolate were as follows: lactose fermentation negative, H2S positive, IMVIC (-,+,-,+), urease negative, lysine/ornithine decarboxylase positive and motile. The bacteria was then identified as Salmonella enterica serotype Kentucky (8,20;i;z6) by agglutination tests. Antibiotic susceptibility tests were conducted according to CLSI guidelines and it was found as ampicillin- and ciprofloxacin-resistant. Ciprofloxacin resistance of the isolate was confirmed with E-test. Stool culture was performed to investigate the source of infection, and S. Kentucky was isolated. On the 15th day of SCF treatment, LVAD was taken out, and tissue cultures taken from the fibrillar tissues between pericardial layers during surgery, also yielded S. Kentucky growth. On the second day of SCF therapy the patient's fever returned normal and on the seventh day, CBC and CRP values were normalized. Nevertheless, the clinical situation of the patient worsened gradually and on the 40th day he was intubated due to low oxygen saturation and pleural effusion. His antibiotherapy was stopped on 42nd day as the blood cultures were negative and his clinical situation was attributed to cardiac failure. The patient died four days after the antibiotherapy has stopped due to cardiac reasons. To our knowledge, this is the first reported case infected with ciprofloxacin-resistant Salmonella Kentucky in our country.

[Determination of Salmonella serotypes by conventional and molecular methods]. / Salmonella Serotiplerinin Konvansiyonel ve Moleküler Yöntemler ile Belirlenmesi.

Determination of Salmonella enterica serotypes is crucial for epidemiological studies. Salmonella serotypes are defined on the basis of somatic (O) and flagellar (H) antigens, both of which are present in the cell wall of Salmonella. The aim of this study was to compare the results of molecular serotyping obtained by multiplex polymerase chain reaction (mPCR) with conventional serotyping results. Conventional serotyping has been performed in Ministry of Health Refik Saydam Hygiene Center as part of the National Laboratory of Enteric Pathogenes Surveillance Network (UEPLA). A total of 100 Salmonella strains, thay comprise 14 different serotypes by the reference laboratory have been investigated by using specific primers for Salmonella serogroups (A, B, C1, D and E) and Vi antigen gene clusters via mPCR method. Serotypes have been determined by applying four sequential mPCR targeting the fliC and fliB genes encoding the H1 antigens (H1: a, -b, -d, -g,m, -i, -r, -z10) and H2 antigen complexes (H2: 1,2, -1,5, -1,6, -1,7 and H: enx, enz15). The results of mPCR showed 100% consistency with the serogroups determined by the conventional method. Both sensitivity and specificity of mPCR according to each serogroups were found to be 100%. Results of serotyping that have been determined with the molecular antigenic formula showed accurate results for 2 (2%), probable results for 91 (91%) and incomplete formula for 7 (7%) isolates. Molecular serotyping results of the most common isolated Salmonella serotypes of which S.Enteritidis, S.Typhimurium and S.Paratyphi from clinical microbiology laboratories have been determined as probable results. Antigenic formula of these serotypes that detected using mPCR were considered to be consistent with the results of conventional serotyping when interpreted with epidemiologic data. The sensitivity of mPCR to identify S.Typhi which have been determined as accurate result with molecular serotyping was 100% for serogrouping and serotyping. Multiplex PCR is cheaper and faster for the serotyping of strains isolated in clinical laboratories, compared to the conventional methods. However since it is not possible to detect all serotypes by using molecular typing, this technique can not be currently considered as an alternative for conventional serotyping. Nevertheless molecular typing could be beneficial in providing the preliminary results earlier.

[Investigation of verotoxigenic Escherichia coli O157:H7 incidence in gastroenteritis patients]. / Gastroenteritli olgularda verotoksijenik escherichia coli O157:H7 insidansinin arastirilmasi.

Escherichia coli O157:H7 is the most common serotype among verotoxigenic E.coli (VTEC) strains that cause haemolytic uremic syndrome. Although sporadic VTEC cases originating from Turkey and small outbreaks have been reported from our country, VTEC has not been routinely investigated in most of the diagnostic microbiology laboratories in Turkey and studies related to this topic are limited. In this study, the incidence of E.coli O157:H7 in patients who were admitted to Alanya Research and Application Hospital of Baskent University with the complaints of acute gastroenteritis between September 2005 and September 2008, was investigated. Stool samples collected from 1815 diarrheal patients (of them 50.5% were male; 49.3% were ? 5 years old; 10.2% were tourists) were evaluated initially by direct microscopy and then inoculated to hectoen enteric agar, EMB agar, Skirrow agar and cefixime tellurite sorbitol MacConkey (CT-SMC) agar media for cultivation. The sorbitol-negative colonies which were compatible with E.coli according to the conventional methods were tested with E.coli polyvalent and 0157 and H7 monovalent antisera and agglutination positive strains were also investigated for verotoxin production in Vero cell cultures. VTEC RPLA toxin detection kit (Oxoid, UK) was used for further identification of toxin type of verotoxin positive strains. Fecal leukocytes were detected in 41.3% of the samples in direct microscopy, while 27% (173/639) of the samples were also found positive for amoeba antigen, 6% (24/396) for rotavirus antigen, 1.2% (22/1815) for Salmonella spp., 0.6% (11/1815) for Shigella spp., 0.2% (4/1815) for Giardia trophozoites and 0.06% (1/1815) for Campylobacter jejuni. The isolation rate of sorbitol-negative E.coli strains was %0.8 (14/1815), and two of them were identified as E.coli O157:H7 by monovalent antisera, and both of them were determined as verotoxin-producers in cell culture. Verotoxin types of those isolates were found as verotoxin 1 in one strain and verotoxin 1 + verotoxin 2 in the other. The two patients infected with verotoxigenic E.coli O157:H7 were both tourists (one was 7 and the other was 35 years old) and admitted to the emergency room of hospital with complaints of bloody diarrhea. No further investigation directed towards the origin of the pathogen could be performed in the hotels of these patients. These data indicated that VTEC O157:H7 incidence was low (2/1815; 0.1%) in our area during the study period. Thus, routine testing of stool samples for E.coli O157:H7 does not seem to be cost-effective. However, E.coli O157:H7 should necessarily be investigated at least in bloody diarrhea cases since this pathogen has serious morbidity, mortality and complications like haemolytic uremic syndrome, hemorrhagic colitis and also due to its epidemiological significance.