Comparison in a rat thigh abscess model of imipenem, meropenem and cefoperazone-sulbactam against Acinetobacter baumannii strains in terms of bactericidal efficacy and resistance selection

BACKGROUND: We compared imipenem, meropenem and cefoperazone-sulbactam against hospital originated A. baumannii strains in terms of bactericidal efficacy and selection of resistant mutants during treatment in a rat thigh abscess model. METHODS: A total of 18 strains were inoculated in 54 animals (one strain for three animals). Randomly selected 10 among these 18 strains were inoculated in another 10 rats as the control group. Imipenem, meropenem and cefoperazone-sulbactam were the antibiotics compared. After four days of treatment, Wistar albino rats (200 to 250 g) were sacrificed and the abscess materials were processed for mean colony counts and for the presence of resistant mutants. RESULTS: The mean CFUs per gram (mean ± (std. deviation) [×10(4)]) of the abscess were: 9,14 (25,24), 2,11 (3,78), 1,20 (1,70) in the imipenem (n = 17), meropenem (n = 18) and cefoperazone-sulbactam (n = 17) groups, respectively. The differences were not significant. On the other hand, no resistant mutant was detected in abscess materials. CONCLUSION: This study indicated; first, cefoperazone-sulbactam is comparable to carbapenems in bactericidal efficacy in this particular abscess model and second, emergence of resistance due to spontaneous mutations is not at least a frequent phenomenon among A. baumannii

Investigation of levels of adenosine, deaminase, and subtle interleukin-2 in cerebrospinal fluid in purulent, tuberculosis and viral meningitis

Tıp dünyasında tüm teknolojik ilerlemelere rağmen menenjitlerin ayırıcı tanısı hala büyük bir problemdir.özellikle beyin omurilik sıvısında (BOS) düşük sayıda hücresi olan pürülan menenjit (PM), başlangıç dönemindeki viral menenjit (VM) ile 1 tüberküloz menenjit (TBM) sıklıkla karışmaktadır.Çalışmamızda t beyin omurilik sıvısında adenosin deaminaz (ADA) aktivitesi ile solübl interlökin-2 reseptör (sIL-2R) düzeylerini ölçtük.ADA enzimi pürin katabolizmasında rolü olan bir enzimdir.T lenfositlerde saptanmıştır.sIL-2R T ve B hücre aktivasyonu sonucunda oluşan ve patogenezinde hücresel immünitenin rol oynadığı birçok hastalıkta artan bir moleküldür. Menenjit olgularında her iki testin, TBM'in VM'ten ayırd edilmesinde çok yararlı olduklarını saptadık. Bazı olgularda PM ile TBM' deki BOS değerlerinin üst üste çakışması nedeniyle bu iki menenjitin ayırd edilmesinde ek parametrelerin de dikkate alınarak değerlendirme yapılmasının faydalı olacağı kanaatindeyiz

Investigation of Tularemia Incidence and Presence of Francisella tularensis in Streams/Mains Water in a Risky Region of Thrace

WOS: 000464106600016Objective: Tularemia was first detected in Thrace region in our country and the outbreaks continued in the region over the following years. The fact that the agent has been identified in mice around Kaynarca in 2012 suggests the disease poses a risk for our region. Aim of this study was to investigate tularemia incidence and presence of Francisella tularensis in streams/mains water in a risky region of Thrace. Methods: In this study, seropositivity for tularemia was investigated in 13 villages, and 1 town in risky areas of the Thrace region. In January 2016, blood was drawn from 746 people and tularemia microagglutination tests were applied. Seropositivity was not detected. In December, 464 of 746 people were reached. Seroconversion was not observed. In addition, culture and polymerase chain reaction (PCR) procedures were applied to specimens collected from mains water and streams in 13 villages and 1 town. Results: The causative agent wasn't isolated from the cultures but F. tularensis DNAs were detected by PCR method in 2 stream, and 3 mains water samples. One of the streams passed through the village of Celaliye, which was very close to Kaynarca, where tularemia cases were seen in the past. The other was farther, passing through the Kavakli town in which no cases has been reported. The mains water which were positive were from Hamzabey, Ceylankoy, and Tatarkoy villages located around Kaynarca. Molecular examination after chlorination was repeated in the water sources in which positivity was detected, and it was seen that the agent was eliminated. Conclusions: In this study, incidence was calculated as zero, although the causative agent was found in the water. Although no seropositivity was detected, the detection of the agent by PCR in 5 water samples showed that the agents in the nature could reach the water resources. It has been observed that surveillance studies in risky areas could be effective in preventing possible outbreaks

Evaluation of Resistance Transfer by Conjugation, in Escherichia coli, Klebsiella and Salmonella Species, on Solid Phase at Different Temperatures

Conjugation means transfer of genetic material via bacterial membranes. Fimbrial characters that are responsible for this transfer are coded by conjugative plasmids that multiply in the cytoplasm. This transfer efficiency may be different in solid, liquid phases or on membranes. Conjugation in some of the members of Enterobacteriaceae family is also temperature dependant. This study was carried out to determine the optimal temperature and donor-acceptor ratios for transconjugation in Escherichia coli, Klebsiella and Salmonella species which belong to Enterobacteriaceae family. Fifteen strains, five from each of these species that mentioned above, which were determined to be multiresistant, were introduced to standart recipient E. coli J53-2 in two different concentration [(a) donor:recipient ratio 4:1; and (b) donor:recipient ratio is 1:4] and three different temperatures 32°C, 37°C and 42°C. “Multivariate” analysis was done with “repeated measures one way ANOVA test” whereas “univariate” analysis was done with “Wicoxon Sign Rank” tests. The results of these two tests correlated well and the results were found to be statistically different. In conclusion, transconjugation on solid phase was found to be optimal for group (b) where the recipient:donor ratio was 4:1 and the temperature was 37°C

Microbiological Approach to a Possible Infective Endocarditis Case Caused by Aggregatibacter actinomycetemcomitans

Aggregatibacter (Actinobacillus) actinomycetemcomitans, a small, gram-negative coccobacillus that grows slow and fastidious, is generally colonized in the oral cavity. It is a rarely seen bacterium because of the difficulty of isolation but it can be a causative agent for dental infections and infective endocarditis (IE) particularly in the persons having prosthetic heart valves. In this report, a possible IE case caused by A.actinomycetemcomitans in a patient with aortic valve replacement has been presented. A 36-year-old man has admitted to Trakya University Hospital, Health Center for Medical Research and Practice, with the complaints of chills, malaise, intermittent fever, severe arthralgia and weight loss (20 kg). During his follow-up period, the blood cultures that were obtained three week intervals yielded the identical gram negative coccobacilli morphology. The patient was then diagnosed as possible IE on the basis of having one major (growth of the typical microorganisms that may cause IE in two different blood cultures) and two minor (presence of prosthetic valve and high fever) criterias. The isolate could not be identified with conventional methods, while it was identified as Francisella tularensis with VITEK 2 (bioMerieux, France) system. Hence this identification was not confirmed by real-time Taqman polymerase chain reaction, so MALDI-TOF mass spectrometry was used to identify this bacteria. In the first run of the study, the isolate was named as Shigella dysenteriae initially, however when it was retested the next day it was identified as A.actinomycetemcomitans. In order to enlighten these conflicting results, 16S and 23S ribosomal DNA sequence analysis was performed, and consequently the bacterium was identified as A.actinomycetemcomitans. Doxycycline (2 x 100 mg po, 20 days) and streptomycin (2 x 10 mg/kg im, 10 days) therapy were initiated, considering the initial suspicious identification (F.tularensis), and on the fifth day of therapy the blood culture was negative with the regression of patient's complaints. Therapy continued with the addition of rifampicin to doxycycline from the 21(st) day and the patient discharged with cure. As a result, the identification of an exceptional bacterium like A.actinomycetemcomitans may be difficult and time-consuming in certain laboratory facilities. So, the use of different identification methods in addition to classical methods are needed to overcome such a problem, especially for uncommon isolates and clinically discordant cases. This case was presented because A.actinomycetemcomitans is a rare etiological agent for IE patients and it could be a good example to draw attention to the problem when identifying the organism using automatized identification systems

Renal outcome with eculizumab in two diarrhea-associated hemolyticeuremic syndrome cases with severe neurologic involvement

İstanbul Bilim Üniversitesi, Tıp Fakültesi.The kidney and brain are the two target organs in patients with Shiga toxin-producing Escherichia coli-associated hemolytic–uremic syndrome (STEC-HUS). Activation of the alternative complement pathway occurs in patients with STEC-HUS. A monoclonal antibody (eculizumab) directed against C5 has been reported to be effective against severe neurologic involvement in patients with STEC-HUS. We report on two STEC-HUS children with severe neurologic involvement treated with eculizumab. Despite prompt resolution of initial neurologic findings upon treatment with eculizumab, proteinuria and hypertension persisted in these patients. The persistence of these two risk factors is particularly emphasized to discuss the long-term effects of eculizumab, especially on renal involvement