Evaluation of an automated system for the detection of carbapenem resistant Acinetobacter baumannii and assessment of metallo-ß-lactamase production using two different phenotyping methods.

We tested 200 clinical Acinetobacter baumannii isolates against imipenem and meropenem using the methods of broth microdilution, disk diffusion, agar dilution, MicroScan/WalkAway automated system. Very major errors were mostly obtained between MicroScan/WA system and disk diffusion test. MicroScan/WA system generated unacceptable errors. Combined disk and modified Hodge tests used for detection of metallo-ß-lactamase production were practical and useful.

[In vitro tigecycline and carbapenem susceptibilities of clinical Acinetobacter baumannii isolates]. / Acinetobacter baumannii klinik izolatlarinin tigesiklin ve karbapeneme karsi in vitro duyarliliklari

Acinetobacter baumannii is a frequent cause of nosocomial infections in most hospitals. Management of infections caused by these strains is difficult, as the strains often display multiple drug resistance, including carbapenem. Tigecycline which is a glycylcycline derivative has antimicrobial activity against many gram-positive and gram-negative organisms. In this study, in vitro activity of tigecycline and carbapenems against clinical isolates of A.baumannii strains were investigated. A total of 100 A.baumannii isolates were collected from hospitalized patients with documented nosocomial infections [pneumonia (n = 39), surgical wound infection (n = 32), bacteremia (n = 16), catheter infection (n = 6), urinary tract infection (n = 5), peritonitis (n = 1), eye infection (n = 1)] between October 2006 and June 2007. Only one isolate per patient was included to the study. Minimum inhibitory concentrations (MIC) of tigecycline were determined by E-test (AB Biodisk, Sweden). Carbapenem resistance of A.baumannii strains were determined by disk diffusion method. All of the 100 A.baumannii isolates (100%) were found susceptible to tigecycline (MIC values ≤ 2 µg/ml; MIC ranges: 0.032-1.5 µg/ml). Imipenem susceptibility test was performed for 95 strains, and 36 (37.9%) were found sensitive, 18 (18.9%) were intermediate sensitive, and 41 (43.2%) were resistant. Meropenem susceptibility test was performed for 87 strains, and 22 (25.3%) were found sensitive, 9 (10.3%) were intermediate sensitive, and 56 (64.4%) were resistant. Since tigecycline is found quite effective on nosocomial A.baumannii isolates, it may be considered as a treatment alternative in infections caused by carbapenem-resistant Acinetobacter spp.

[Is pneumatic sample transport system also a carrier for microorganisms?]. / Pnömatik sistem mikroorganizmalar için de tasiyici mi?

The purpose of this study was to evaluate the possible infection and contamination risk of the pneumatic system used in our hospital and to establish essential infection control measures. The study was conducted in a quaternary health care center with 1.000 bed capacity. A total of 614 specimens were taken 2 times weekly from the pneumatic transport system and its carriers at 22 wards, 5 intensive care units, 3 laboratories, 2 blood taking units, and pharmacy. Samples were also obtained from the fingertips of 33 subjects using the system, before and after contact with the carriers. A questionnaire that consisted of 8 questions was applied to 224 subjects who worked in those units, evaluating the degree of compliance to the obligations for the cleaning of the pneumatic system and carriers and their approach in case of visible pollution at the system. Bacterial growth was observed in 15.2% (45/296) of samples in the 1st week and 7.6% (18/238) of the samples in the 2nd week, making a total of 11.8% (63/534) bacterial growth. No growth was detected from the areas where the carriers were placed. Of these 69.8% were coagulase negative staphylococci, 11.1% diphteroids, 7.9% Acinetobacter Iwoffii, 4.8% Staphylococcus aureus, 4.8% Bacillus spp. and 1.6% Enterococcus durans. Acinetobacter baumannii and Aspergillus were detected at two fingertip samples taken before the contact with carriers, while again A. baumannii and Enterobacter cloacae were detected at the samples following contact. Moreover, 31.3% of the subjects noted that they cleaned the carriers only if any visible contamination was present. In addition, 14.3% reported that they have encountered broken or spilled up material in the system for more than 5 times, 10.3% reported that they followed the instructions in case of presence of infected material inside the carriers, 23.7% reported that they always washed their hands after any contact with the carriers, 9.8% noted that they always used gloves during contact with the system. Of the subjects 73.7% declared that they had no information about cleaning and decontamination procedures related to the system. These data revealed that the pneumatic system used in our hospital carried contamination risk and the rules for hygiene and disinfection regarding the pneumatic transport system has to be determined, implemented and checked in order to establish appropriate infection control measures.

[The prevalence of intestinal parasites according to the distribution of the patients' gender and parasite species for five years at the Osmangazi University Medical Faculty]. / Eskisehir Osmangazi Universitesinin Bes Yillik Bagirsak Paraziti Prevalansinin Türlere ve Cinsiyetlere Göre Dagilimi.

In this study, patients (outpatients and inpatients) with various gastrointestinal system complaints presenting at various clinics of the Eskisehir Osmangazi University Medical Faculty, from February 2003-December 2007 were investigated for the presence of intestinal parasites. The prevalence of intestinal parasites was evaluated according to parasite species, gender of the patients and the years, in which cases were seen. A total of 34,733 stool samples were prepared by formal-ethyl acetate concentration and examined in saline and iodine preparations microscopically with 10x and 40x magnifications. Also trichrome stained preparations of non-pathogenic amoebas and modi-fied Erlich-Ziehl-Nielsen stained preparations for Cryptosporidium spp were examined by oil-immersion objectives (100x). One or more parasites were found in 1252 of the 34,733 stool samples (including nonpathogenic protozoa).the overall prevalence of intestinal parasitic infection rate was 3.6%, of these patients, 52.5% were female and 47.5% male. Predominant parasites were Entamoeba histolytica/dispar group amoebas (31% (397/1252), followed by Giardia intestinalis 19% (236/1252), Blastocystis hominis 7% (108/1252), and Cryptosporid-ium parvum %4.5 (56/1252). Since the cellophane type method was only used in a few cases; the rates detected in helminth cases in this study were different from other studies. The ratio of E. vermicularis was found to be 2.3% (29/1252), Taenia saginata 0.8% (10/1252) and Strongyloides stercoralis 0.4% (5/1252). In comparison to a previous 10 year retrospective study which was performed in our hospital, we detected an important decrease in prevalence of parasites. But the presence of intestinal parasites is still an important problem.

In vitro activity of ertapenem and other carbapenems against extended-spectrum beta-lactamase producing Escherichia coli and Klebsiella pneumoniae clinical isolates in a tertiary care center in Turkey.

OBJECTIVE: To evaluate the in vitro effect of ertapenem, imipenem and meropenem in clinical isolates of extended-spectrum beta-lactamase (ESBL)-producing strains of Escherichia coli and Klebsiella pneumoniae. DESIGN/METHODS: We studied 82 consecutive clinical isolates of ESBL-producing E. coli (n = 49) and K. pneumonia (n = 33) between February 2006 and September 2007. The minimum inhibitory concentration for each carbapenem was determined using the agar dilution method. RESULTS: Eighty two consecutive microorganisms from sterile sites were evaluated. A total of 48.8% of patients had a history of surgical intervention, 78.0% needed urinary catheterization, 57.3% required vascular access and 40.3% mechanical ventilation; and 70.7% had a history of ICU stay. High resistance rates were shown for both E. coli and K. pneumoniae against cefepime (81.7%), ciprofloxacin (50.9%), tetracycline (75.0%), co-trimoxazole (47.4%), and gentamicin (48.7%). In addition, most K. pneumoniae and E. coli isolates were susceptible to amikacin (78.3%) and piperacilline-tazobactam (91.5%). Meropenem and imipenem showed activity against 100% of the isolates. Ertapenem showed activity against 100% of K. pneumoniae isolates, against 95.9% of E. coli isolates and against 97.5% of the 82 ESBL-producing microorganisms. Two E. coli isolates showed ertapenem resistance. CONCLUSION: In recent literature, carbapenems were the most active antimicrobial agents against ESBL-producing Enterobacteriaceae, as in our study. This is the first study on the in vitro activity of ertapenem against ESBL-producing E. coli and K. pneumoniae conducted in Turkey. In view of the serious infections caused by ESBL-producing microorganisms, therapeutic interventions are still problematic in serious clinical conditions. Ertapenem may be a good choice for treatment, with the additional advantage of being a once a day regimen.

[The relationship between airborne colonization and nosocomial infections in intensive care units]. / Yogun bakim unitelerinde gelisen nozokomiyaL enfeksiyonlar ile hava kaynakli kolonizasyon iliskisi.

The relationship between the airborne contaminants obtained from operating theatres and intensive care units and the colonizing and infecting microorganisms isolated from patients were investigated. Air samples were obtained with the biocollector air IDEAL (BioMerieux, France). During the study period (19 weeks), a total of 77 air samples and 870 clinical specimens (swabs from throat, nose, conjunctiva and skin) from 174 patients were collected weekly. Microorganisms were identified by using Vitek system (BioMerieux, France) and conventional methods. According to the criteria of Federal Standard 209E (FD 209E) on cleanrooms, the conventionally ventilated operating- and general surgery rooms, and the anesthesia intensive care unit have been ranked as less than class 3.5 and 3, respectively. The frequency of nosocomial infection related to air-colonization was higher in patients of anestesia intensive care unit (16.4%), than in those of general surgery intensive care unit (4.9%). In general surgery rooms and anesthesia intensive care unit, the most frequent air-colonization related nosocomial infections were surgical wound infections and bacteremia, respectively. The most frequently isolated microorganisms were methicillin resistant Staphylococcus aureus (MRSA) and Acinetobacter baumannii. It can be concluded that, total number of airborne viable particles in the critical areas such as operating theatres and intensive care units, seems to be a significant risk factor for the development of nosocomial infections in immunocompromised patients.