Fecal calprotectin: can be used to distinguish between bacterial and viral gastroenteritis in children?

OBJECTIVE: Fecal calprotectin is used as a good indicator of intestinal mucosal inflammation. The aim of this study is to evaluate the diagnostic value of fecal calprotectin (f-CP) for the etiology of acute gastroenteritis in children. MATERIALS AND METHODS: All patients presenting with acute diarrhea (<18 years) who had 3 or more soft or watery stools per day were enrolled in this study. Stool microscopic examination and cultures for bacteria and parasites were performed. Polymerase chain reaction test was also applied to stool samples for viruses (Rotavirus, Adenovirus, Norwalk, and Astrovirus). The level of f-CP was carried out by using enzyme-linked immunosorbent assay test. RESULTS: Eighty-four patients with diarrhea were enrolled. The f-CP level was higher in patients with microscopic examination positive (n=17) (median with interquartile range, 1610.0 [908.8-2100] mg/L) than in patients with microscopic examination negative (n=67) (123.8 [25.0-406.3] mg/L) (P<.001). Concentrations of f-CP in patients with stool culture positive (1870.0 [822.5-2100] mg/L) were significantly elevated compared with the concentrations of the patient with virus detected in stool (95.0 [21.3-240.9] mg/L) (P<.001). In the diagnosis for bacterial acute gastroenteritis, the area under the receiver operating characteristic curve for f-CP was 0.867 (95% confidence interval, 0.763-0.971), sensitivity was 88.9%, and specificity was 76.0% if the threshold was taken as 710 mg/L. CONCLUSION: We conclude that f-CP, which is useful, valuable, noninvasive, easily and rapidly measured laboratory test along with simple microscopic examination of stool, can be used as an indicator of intestinal inflammation and to distinguish the bacterial gastroenteritis from the viral gastroenteritis.

[Investigation of plasmid mediated AmpC beta-lactamases among Escherichia coli and Klebsiella pneumoniae isolated from blood cultures]. / Escherichia coli ve Klebsiella pneumoniae Kan Kültürü Izolatlarinda Plazmid Aracili AmpC Beta-Laktamaz Varliginin Arastirilmasi

The aim of this study was to investigate the prevalence and types of plasmid-mediated AmpC (pAmpC) beta-lactamase enzymes in Escherichia coli and Klebsiella pneumoniae strains isolated from blood cultures of hospitalized patients in Dokuz Eylul University Hospital between 2007 and 2012. A total of 261 isolates which consisted of 184 E.coli (70.5%) and 77 K.pneumoniae (29.5%) were included in the study. All isolates were resistant to cefotaxime and/or ceftazidime but susceptible to imipenem. Cefoxitin resistance was investigated as an indicator of AmpC type enzymes. A total of 57 (21.8%) isolates which were cefoxitin-resistant (32 E.coli, 25 K.pneumoniae), were screened for pampC genes by a multiplex polymerase chain reaction (PCR) assay. Additionally, 10 of each cefoxitin susceptible isolates per year were chosen randomly and screened by the same PCR assay to detect the presence of ACC enzymes, which can not hydrolyze cefoxitin. Positive PCR results were confirmed by sequence analysis. Plasmid analysis and macrorestriction analysis were performed for pampC-positive isolates. The presence of pAmpC enzymes has been shown in 9.4% (3/32) of cefoxitin-resistant E.coli, and 8% (2/25) of cefoxitin-resistant K.pneumoniae strains. It was noted that there were no strains producing this enzyme isolated in 2007 and 2008, however the prevalence of pAmpC was detected as 1.6% in 2009 (one ACT-1 producing K.pneumoniae), increasing to 4.8% in 2011 (one ACT-1 producing K.pneumoniae) and 6.4% in 2012 (three CMY-2 producing E.coli). These enzymes were found to be carried on 81 kb size plasmids in K.pneumoniae isolates and on a 9 kb size plasmid in E.coli isolates. Macrorestriction analysis indicated that two of the three CMY-2 producing E.coli had the same PFGE (Pulsed-field gel electrophoresis) pattern. If these two strains are considered as identical, it can be concluded that the prevalence of pAmpC was low in the strains isolated between 2007-2012 (4/261; 1.5%) in our institution. On the other hand, the increasing prevalence of pAmpC in 2011 and 2012 should be considered as a warning for the implementation of infection control measures and monitorization of the prevalence in order to prevent the dissemination of pAmpC. As far as the current literature is concerned, this is the first study that demonstrated the presence of the ACT-1 enzyme in K.pneumoniae isolates in Turkey.

[Investigation of plasmid-mediated quinolone resistance in Escherichia coli strains]. / Escherichia coli Suslarinda Plazmide Bagli Kinolon Direncinin Arastirilmasi

Quinolones are widely used antimicrobial agents, particularly for the treatment of infections caused by gram-negative bacilli such as E.coli. As a consequence, quinolone resistance has been increasing among this species in recent years. Bacterial resistance to quinolones usually results from mutations in the chromosomal genes which encode topoisomerases and also the expression of efflux pumps and loss of porines contributed to development of quinolone resistance. However, recent studies have shown that the spread and increase of quinolone resistance may be due to the transfer of plasmid-mediated genes. To date, three groups of plasmid-mediated quinolone resistance genes, namely qnr, aac(6')-Ib-cr, and qepA, have been described. The aim of this study was to investigate the presence of plasmid-mediated quinolone resistance genes in E.coli clinical isolates. A total of 112 quinolone-resistant E.coli strains isolated from different clinical specimens (84 urine, 16 blood, 10 wound, 2 bronchoalveolar lavage) of which 78 (69.6%) were extended-spectrum beta-lactamase (ESBL) positive, in Afyon Kocatepe University Hospital, Microbiology Laboratory were included in the study. In the isolates, qnrA, qnrB, qnrS, qnrC, qepA, and aac(6')-1b-cr plasmid genes were analysed by polymerase chain reaction (PCR). After aac(6')- 1b determinant was amplified by PCR, all aac(6')-1b positive amplicons were analyzed by digestion with BseGI restriction enzyme to identify aac(6')-1b-cr variant. It was found that, none of the strains horboured qnrA, qnrB, qnrS, qnrC and qepA genes, however, plasmid-mediated quinolone resistance gene aac(6')-1b-cr was found positive in 59.8% (67/112) of the strains. It was notable that 86.6% (58/67) of those isolates were ESBL producers. The rates of quinolone resistance among E.coli isolates infections were high in our region and an increasing trend has been observed in recent years. Our data indicated that the presence of plasmid- mediated resistance genes such as aac(6')-1b-cr, might have contributed to the high quinolone resistance rates. In conclusion, not only qnr genes but all other plasmid-mediated quinolone resistance genes, should be tested for the detection of plasmid-mediated quinolone resistance and this fact should be taken into consideration when the reservoirs are being searched for.

Macrolide resistance determinants in erythromycin-resistant Streptococcus pneumoniae in Turkey.

To determine the major molecular mechanisms of macrolide resistance among Streptococcus pneumoniae isolates in Turkey, we examined a total of 151 isolates collected from different regions of Turkey. Overall, 40 (26.4%) isolates were resistant to erythromycin. The most common mechanism (38/40) was target site modification due to erm (B) genes. Only two isolates harbored the mef (A)/(E) efflux gene. A clonal spread of resistant strains could not be demonstrated by BOX-polymerase chain reaction. The results from this study have shown that the erm (B) gene is predominant in Turkish S. pneumoniae isolates, as in isolates from the rest of the world, and a clonal dissemination is not responsible for this resistance profile.

qnrA prevalence in extended-spectrum beta-lactamase-positive Enterobacteriaceae isolates from Turkey.

Quinolone resistance mostly originates from chromosomal mutations. In recent years, however, plasmid-mediated quinolone resistance has been reported in several parts of the world. Plasmid-borne qnrA, qnrB, or qnrS genes are responsible for this kind of resistance. Little is known about the diversity, type, and species range of the qnr genes in Turkey. We screened qnrA, qnrB, and qnrS genes in quinolone-resistant blood culture isolates collected from six different medical centers in Turkey which produced extended-spectrum beta-lactamases (ESBLs). A total of 78 ESBL-positive isolates were enrolled in this study. Of these, 37 (47.4%) were nalidixic-acid resistant or intermediate. qnrA was found on large plasmids isolated from five (6.4%) of the Nal(I/R) isolates. In three of these, the same plasmid also carried bla(CTX-M). Four of the qnrA-positive isolates were Klebsiella pneumoniae from Dokuz Eylul University Hospital, Izmir, and the fifth isolate was Escherichia coli from Istanbul University Hospital. Two of the isolates from Izmir were found by enterobacterial repetitive interegenic consensus sequence-PCR to be clonally related. This is the first report on the qnrA prevalence among ESBL-positive blood culture isolates collected from different regions in Turkey. According to our results, plasmid-mediated resistance is a potential problem for the spread of quinolone resistance, and this mechanism could be emerging strongly among the ESBL-positive Enterobacteriaceae in Turkey.

[Molecular epidemiologic surveillance and antifungal agent sensitivity of Candida albicans isolated from anesthesia intensive care units]. / Anestezi yogun bakim ünitesi hastalarindan izole edilen Candida albicans suslarinin antifungal ajanlara duyarliligi ve moleküler epidemiyolojik izlemi.

Patients in intensive care units (ICU) are at risk of nosocomial infections. The incidence of nosocomial fungal infections has increased in parallel with the increase of nosocomial infections. Candida albicans is the most frequent pathogenic species among the fungi. The aim of this study was to make an epidemiological surveillance of C. albicans urine isolates which were isolated from patients who were hospitalized in ICU between June 2000 and October 2001 by antifungal susceptibility testing and Randomly Amplified Polymorphic DNA (RAPD) analysis. For this purpose, 38 C. albicans which were isolated from 29 patients were investigated for amphotericin B and fluconazole susceptibility with the microdilution method. The range of minimal inhibitory concentration (MIC) of amphotericin B was between 0.25-1 microgram/ml and MIC50 value was 0.5 microgram/ml and none of the isolates had high (MIC > 1 microgram/ml) MIC values. The MIC values for fluconazole varied between 0.25-16 micrograms/ml and MIC50 value was 1 microgram/ml. While none of the isolates was resistant to fluconazole, two isolates were detected as dose dependent susceptible. RAPD analysis was performed with two different primers in order to investigate clonal relationship, and 22 patterns were detected with one of the primers and 24 patterns were detected with the other. In conclusion, it is thought that the origin of the C. albicans urine isolates were mostly endogenous but exogenous spread might also be considered as isolates that were clonally related were isolated from different patients at the same time interval.

The first report on the outbreak of OXA-24/40-like carbapenemase-producing Acinetobacter baumannii in Turkey.

Carbapenem resistance due to OXA-type carbapenemases seriously limits therapeutic options in nosocomial infections caused by Acinetobacter baumannii. Previous studies have shown the presence of OXA-51, OXA-58, and OXA-23 carbapenemases but not OXA-24/40 in A. baumannii in Turkey. In this study, we investigated carbapenem-hydrolyzing class D ß-lactamases (CHDLs) in A. baumannii and the molecular epidemiology of CHDL producers at the Dokuz Eylul Hospital, Izmir Turkey, and detected blaOXA-24/40 in a clinical isolate from a patient in the medical intensive care unit (ICU). The specific enzyme type was OXA-72. Additional studies revealed 22 more isolates from 20 patients and that the OXA-72-producing strain caused an outbreak in the medical ICU from September 2012 to March 2013, which still continues. To our knowledge, this is the first report of OXA-24/40 carbapenemases in A. baumannii in Turkey. Emergency infection control should be implemented following the arrival of a new OXA at a hospital where A. baumannii is highly endemic.

CTX-M-3 extended-spectrum beta-lactamase in a Shigella sonnei clinical isolate: first report from Turkey.

A Shigella sonnei strain resistant to cefotaxime and aztreonam (but not ceftazidime) was isolated from the stool sample of a 7-y-old outpatient. Double disk synergy test, isoelectric focusing, polymerase chain reaction and sequence analysis confirmed that the isolate produced CTX-M-3, an extended-spectrum beta-lactamase (ESBL). This is the first report from Turkey of Shigella spp. producing an ESBL, and of CTX-M type enzyme.