TABLE OF CONTENT

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1. PHENOTYPIC DETECTION OF OXA-48-PRODUCING ENTEROBACTERIAL ISOLATES BY ROUTINE ANTIBIOGRAM

S. Sabtcheva

ABSTRACT
Carbapenemase-mediated resistance in Enterobacteriaceae has increased in the last years, seriously compromising the management of lifethreatening infections. Rapid detection of carbapenemase producers is essential for the control of their dissemination, for the successful treatment of infected patients and the preservation of carbapenem efficacy.

According to EUCAST methodology carbapenemase inhibition tests with boronic acid derivatives and dipicolinic acid/EDTA combined with a  temocillin disc provide a reliable phenotypic confirmation method for class A, B and OXA-48 carbapenemases in Enterobacteriaceae. Using peculiar hydrolysis profile of OXA-48 enzymes and the high-level resistance to temocillin we developed a cost-effective disk-based method to screen for  OXA-48- producers within routine antibiogram. The test is a potentially useful diagnostic tool especially for difficult-to-detect OXA-48-positive/ESBL-negative Enterobacteriaceae. It can provide important infection control information and help to ensure appropriate antibiotic therapy of the infected patients.


2. UPDATES ON MOLECULAR EPIDEMIOLOGY OF S. TYPHI IN BULGARIA WITH REVIEW OF OUTBREAK AND SPORADIC CASES, 2008-2014

G. Asseva, P. Petrov, E. Bozova, S. Petkova, P. Padeshki, K. Ivanova, I. Ivanov, E. Dobreva, M. Pavlova, I. Tomova, T. Kantardjiev

ABSTRACT
This work provides an update in molecular epidemiology of typhoid fever in Bulgaria. A total of 15 patients were diagnosed with typhoid fever in Shumen region between 2008-2014. Another two cases occurred in Sofia in 2008 and 2012, but were imported from another countries. Fifteen S. Typhi isolates were confirmed with microbiological methods between 2008-2014, 10 of them were studied with pulsed-field gel electrophoresis (PFGE). The three main pulsotypes discovered allowed to differentiate between local endemic (I type) and imported cases (II and III types). All isolates originating from Shumen, Bulgaria were further subdevided to four subtypes, which were closely related between themselves. Eighty percent of Bulgarian S. Typhi isolates were susceptible to a set of twelve antimicrobial agents including the fluoroquinolones, which was a favorable trait for the successful treatment of the patients. One of the imported S. Typhi isolates characterized with diminished zones to ciprofloxacin and resistance to nalidixic acid was negative for qnr and qepA genes.


3. PREVALENCE OF HELICOBACTER PYLORI SEROPOSITIVITY IN PATIENTS WITH PSORIASIS

G. Zhelezova, L. Yocheva, L. Tserovska, G. Mateev, S. Vassileva

ABSTRACT
Helicobacter pylori is Gram-negative, spirally shaped flagellate bacterium. It is microaerophilic, fastidious and highly adapted to live in the gastric mucosa. Different parts of the stomach may be colonised, with the most common location – the gastric antrum. Protection against gastric acid is provided by the powerful urease activity of the bacterium. In this way it can successfully survive in the gastric acidic environment.

The global prevalence of H. pylori infection is more than 50%. It is implicated in some of the most common and socially significant gastroduodenal human diseases,such as chronic gastritis, peptic ulcer disease, gastric adenocarcinoma and MALT lymphoma.The infection caused is chronic and if untreated, persists throughout life. In the majority of infected cases (about 80%) there are no complaints reported, but a chronic gastritis can be detected histologically. Such persons are considered to be asymptomatically infected or colonised.

The immune response that develops as a result of H. pylori infection is generatednot only locally, but on a systemic level as well. In the serum, antibodies to different antigens of the bacteria are found and this determines the individuals as seropositive. Strains of H. pylori are associated with different virulence factors. Some ofthem possess genes of the so-called Islands of pathogenicity - cagA and vacA, encodingthe proteins CagA and VacA,which areconsidered to be the main factors of virulence. Their presence is associated with induction of strong gastric inflammation, synthesis of proinflammatory cytokines, carcinogenic potential, etc. There is a strong humoral immune response to these antigens which can characterise the degree of virulence of the strains. Although H. pylori stimulates animmune response, this is not efficient enough and the infection persists. The microorganism produces a low-level inflammation at systemic level for decades. The increase in proinflammatory cytokines in the blood can act as a starting point in the stimulation of the inflammatory cascade which is possible predisposition for the development of chronic inflammatory diseases.
Data from many studies find the relationship between H. pylori infection and diseases that are not related to the gastrointestinal tract (cardiovascular, metabolic, skin disorders). The chronic inflammatory nature of H. pylori infection is considered to predispose patients to a number of skin diseases - rosacea, chronic urticaria, atopic dermatitis, psoriasis, etc.

Psoriasis is a chronic inflammatory dermatosis of unknown etiology. Data collected on the role of H. pylori infection in such patients is contradictory, but the well-knownability of the bacterium to induce systemic chronic inflammation at low grade, suggests its possible implication in the etiopathogenesis of the disease. In Bulgaria about 100,000 patients with psoriasis are registered. The rate of infectivity with H. pylori among this populationhas not been investigated. This study demonstrates the first results on seroprevalence of H. pylori and presence of the virulence factors CagA and VacA in Bulgarian psoriasis patients without gastrointestinal tract complaints.


4. HIV-1 TRANSMITTED DRUG RESISTANCE IN BULGARIA

I. Alexiev, R. Dimitrova, A. Gancheva, A. Kostadinova, I. Elenkov, M. Stoycheva, D. Nikolova, M. Nikolova, M. Muhtarova, D. Radkova, D. Beshkov

ABSTRACT
Objectives: The aim of our study was to determine transmitted drug resistance (TDR) in Bulgaria.

Methods: The prevalence of TDR was determined in 305/1446 (21.1%) persons newly diagnosed with HIV/AIDS from 1988 - 2011. TDR mutations (TDRM) in protease (PR) and reverse transcriptase (RT) of the pol gene were defined using the WHO HIV drug mutation list.

Results: TDRM was found in 16/305 (5.2%) persons, eleven (3.6%) with resistance to nucleoside reverse transcriptase inhibitors (NRTIs), five (1.6%) with resistance to non-nucleoside reverse-transcriptase inhibitors (NNRTIs) and three (0.9%) with resistance to PR inhibitors. Dual class TDRM were found in three (1.0%) patients. TDRM were found in ten heterosexuals (HET), four men reporting sex with men (MSM) and two intravenous drug users (IDUs).

Conclusions: We found a low prevalence of TDR among antiretroviral naive patients in Bulgaria. Our results provide baseline data on TDR and support continued surveillance of high risk populations in Bulgaria to better target treatment and prevention efforts.


5. CD4/CD8 RATIO FOR MONITORING THE IMMUNOLOGICAL RESPONSE TO COMBINED ANTIRETROVIRAL THERAPY IN BULGARIAN HIV+ PATIENTS

M. Muhtarova, O. Angelova, M. Alexandrova, I. Elenkov, D. Beshkov, I. Aleksiev, H. Taskov, M. Nikolova

ABSTRACT
Background:
HIV viral load (VL) and CD4 absolute count (CD4AC) are traditionally used to monitor combined antiretroviral therapy (cART) of HIV-1+ patients. Accumulating data indicate that additional parameters might contribute to the prognosis and evaluation of cART effects. We analysed the   effects of cART in Bulgarian HIV-1+ patients treated during 2003-2013, comparing CD4AC and CD4/CD8 as parameters for immune monitoring.

Material and methods: The study included 643 treatment-naive HIV-1+patients (male/female: 475/168), started on cART between January 2003 –  December 2013. Immunologic (CD4AC, CD4/CD8) and viral response were evaluated in the course of 5 years by multicolour flow cytometry (BD  Biosciences), and RT-PCR (Roche-Diagnostics). At least 40 cases were analysed for each time point.

Results: According to baseline CD4AC (cells/µl), subgroups with low-L (<200, n=347), medium-M (200–350, n=143), and high-H (>350, n=119)  count were defined. CD4AC change (∆CD4) and viral success (VS, VL<1.6) rates in the subgroups at 6, 24 and 60mo were comparable (Fischer’s p>0.05). Average CD4AC entered reference range in 36mo at latest (L) while CD4/CD8 remained low even at 60mo. Baseline ratio independently of  CD4AC was associated with better early immune response (р<0.05). Baseline CD4/CD8 predicted cART effect independently of CD4AC, and  improved predictive value of CD4AC only in subgroup L. Regardless of VS, low CD4/CD8 at 6, 24, and 60mo was significantly associated with poor  immune recovery (ΔCD4, p<0,001).

Conclusions: In addition to CD4AC, CD4/CD8 is an important surrogate marker of immune recovery most probably reflecting accelerated immune  senescence in conditions of ongoing low-level activation.


6. HEPATITIS B AND HEPATITIS C AS CO-INFECTIONS IN PATIENTS WITH HIV/AIDS

А. Petrov, М. Stoycheva, N. Vatev, V. Georgieva, М. Atanassova, M. Semerdjieva, P. Gardjeva

ABSTRACT
Introduction:
One third of HIV/AIDS patients are typically co-infected with viral hepatitis B and C (HBV and HCV). This rate is even higher, reaching up to 60-90%, in intravenous drug users. There is a significant double risk for HIV-positive patients co-infected with hepatitis to develop liver failure with lethal outcome.

Objective: The aim of the present study was to perform clinical and epidemiological analysis of HIV/AIDS patients with hepatotropic virus co-infection and also to investigate the correlation between the degree of immune suppression and the level of liver damage.

Materials and Methods: 86 HIV/AIDS patients co-infected with hepatotropic viruses were included in the study. During the period January 2010 - May 2014 they followed-up at the Clinic of Infectious Diseases and Parasitology, St. George University Hospital, Plovdiv subsequently after treatment. Epidemiological analysis and clinical monitoring was conducted. Laboratory examinations included 12 different parameters, determination of CD4 and viral load (VL).

Results: Out of 164 HIV/AIDS patients in total, 86 (54.2%, 80 men and six women) had hepatitis co-infection. Six patients had HIV/HBV, 14 had HIV/HBV/HCV, and 66 were co-infected with HIV/HCV. Hospital admission rates for these patients were higher and most of them were drug abusers. A definite correlation was established between CD4, VL counts and the degree of liver damage and aminotransferase level. Between January 2010 and May 2011 lethal outcome was registered in 31 patients, 29 of whom had co-existing infection with hepatotropic viruses.

Conclusion: Co-infections with HBV and HCV among HIV-positive individuals were present in more than 50% of the studied patients. They pose an important risk factor for morbidity, frequent hospital admissions and lethality.


 

Editor-in-Chief
Prof. T. Kantardjiev, MD, DSc

Editorial Board
Acad. B. Petrunov, MD, DSc
Prof. I. Christova, MD, DSc
Prof. M. Kojuharova, MD, PhD
Prof. P.Teoharov, MD, DSc
Assoc. Prof. I. Rainova, MD, PhD

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