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The objective of this study was to determine some features of cystic echinococcosis among children and adolescents, such as epidemiology, diagnosis, organ localization, treatment, and social and environmental factors favoring transmission of the disease. The 18-year study period (1996-2013) includes officially registered primary cases treated surgically, and/or with drug therapy, and/or with the puncture, aspiration, injection, reaspiration technique. Organ localization of the cysts and the most common diagnostic procedures were studied from the patients' medical records. Groups of diseased and healthy children were surveyed to outline some of the environmental and social factors influencing morbidity. From 1996 to 2013, the average annual incidence of cystic echinococcosis in the country was 6.7 per 100,000, but with significant variations in the incidence between different age groups. The hydatid cysts in children aged 0 to 9 years may most frequently be found in the lungs, in contrast to patients from other age groups. Almost 90 % of the affected children had sustained contact with dogs. At present, among the countries of the European Union, Bulgaria holds the highest incidence and prevalence of cystic echinococcosis. Childhood echinococcosis remains a serious health problem for the country. Therefore, the study of cystic echinococcosis in children has important epidemiological significance concerning the intensity of transmission. [ABSTRACT FROM AUTHOR]

The purpose of this investigation was to review the clinical cases diagnosed as systemic or extraintestinal salmonellosis between 2005 and 2010 in Bulgaria, to determine the antimicrobial resistance of the causative salmonellae, and to analyze the pulsed field gel electrophoresis (PFGE) profiles of extraintestinal Salmonella Corvallis isolates. Culture, biochemical tests, and serotyping were performed. Resistance to 12 antimicrobial agents was studied with the Bauer-Kirby disk diffusion method. The double-disk synergy method was used for the screening of the presence of extended-spectrum beta-lactamases (ESBLs). PFGE typing and analysis of the dendrogram was performed for the comparative investigation of Salmonella Corvallis isolates. Between 2005 and 2010, 2,227 human non-typhoid Salmonella isolates were investigated at the National Reference Laboratory of Enteric Pathogens, Sofia, Bulgaria. Thirty-three strains (1.48 %) from nine national regions were isolated from patients with systemic and extraintestinal forms of salmonellosis. The serotype distribution was as follows: S. enteritidis ( n = 21), S. choleraesuis (diphasic n = 3; monophasic n = 3), S. typhimurium ( n = 2), Salmonella Corvallis ( n = 2), Salmonella Montevideo ( n = 1), and S. javiana ( n = 1). Eight patients developed severe forms of infections: sepsis ( n = 2), septic shock ( n = 1 with fatal outcome), meningitis ( n = 3), and acute renal failure ( n = 2). Twenty-two percent of isolates were resistant to ampicillin and gentamicin, 17.64 % to tetracycline, 14.28 % to nalidixic acid, and 10 % to chloramphenicol. All isolates were susceptible to ciprofloxacin. One Salmonella Corvallis isolate recovered from a patient with chronic hemolytic anemia produced an ESBL and its PFGE profile demonstrated less than 96 % similarity to fecal and wound Salmonella Corvallis with susceptible phenotypes. S. enteritidis was the most common cause of systemic and extraintestinal forms of human salmonellosis in Bulgaria. Resistance to ampicillin and gentamicin were the predominant profiles, although one Salmonella Corvallis isolate produced an ESBL. The ESBL-producing Salmonella Corvallis isolate clustered separately from the susceptible Salmonella Corvallis isolates. [ABSTRACT FROM AUTHOR]

In 2006, Salmonella enterica serovar I 9,12:l,v:- emerged in Bulgaria. The aim of this study was to characterize Salmonella serovar I 9,12:l,v:- isolates from Bulgaria, Denmark, and the United States. We compared isolates of Salmonella I 9,12:l,v:- and diphasic serovars with similar antigenic formulas by pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility. The phase 2 flagellin gene ( fljB) was also sequenced for selected isolates. By PFGE, the Salmonella I 9,12:l,v:- isolates from Bulgaria were indistinguishable from the isolate from the United States and distinct from isolates from Denmark; furthermore, several Salmonella I 9,12:l,v:- were indistinguishable from an isolate of Salmonella serovar Goettingen. Sequence analysis showed 100% sequence identity with known H:e,n,z15 sequences of Salmonella Goettingen, which has the antigenic formula I 9,12:l,v:e,n,z15. The study indicated that Salmonella I 9,12:l,v:- is a monophasic variant of Salmonella Goettingen and is present in different countries and on different continents. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented which discusses several cases caused by CTX-M-3-producing Salmonella Brandenburg among children in Bulgaria.

Abstract: Objectives: The antimicrobial susceptibility of anaerobic bacteria isolated from clinical specimens in the referent for Bulgaria anaerobic laboratory was studied in a period of 25 years/1983–2007/. Methods: NCCLS – recommended agar dilution methods were used. β-lactamase activity was determined with nitrocefin discs. Results: The 29 antimicrobial agents included in the study were divided according to their in vitro activity against the anaerobic isolates into 4 main groups for guiding empirical treatment: 1st group of metronidazole, chloramphenicol, meropenem, imipenem and combinations of β-lactam antibiotics with sulbactam – with high activity and drugs of choice for treatment; 2nd group – clindamycin, cefoxitin, carbenicillin/and azlocillin, piperacillin/ – with a good activity and low percent of resistant strains; 3rd group – of tetracycline and erythromycin with higher percent of resistant strains including the new macrolides as josamycin, clarithromycin, roxithromycin and azithromycin; 4th group – penicillins/ampicillin, amoxicillin, penicillin/and cephalosporins/cefamandole, cefazolin, cefotaxime and cefoperazone/ – not suitable for treatment of infections including Bacteroides fragilis group strains, with a very high percent of resistant strains, probably due to β-lactamase activity in most of the strains. Conclusion: A continued updating and a follow-up in the changes of antibiotic susceptibility are necessary in every country as resistance patterns vary not only between geographical regions but also even among medical centers and hospitals which may be connected with differences in antibiotic usage in man and animals. [Copyright &y& Elsevier]

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has brought about significant challenges worldwide. In this study, we present a comprehensive analysis of the genomic epidemiology and lineage dynamics of SARS-CoV-2 in Bulgaria over a three-year period. Through extensive genomic sequencing and data analysis, we investigated the evolution of the virus, the emergence of variants of concern (VOCs), and their impact on the country's pandemic trajectory. We also assessed the relationship between viral diversity and COVID-19 morbidity and mortality in Bulgaria. Our findings shed light on the temporal and spatial distribution of SARS-CoV-2 lineages and provide crucial insights into the dynamics of the pandemic in the country. The interplay between international travel and viral transmission plays a significant role in the emergence and dissemination of different SARS-CoV-2 variants. The observed proportions of exportation to various continents provide insights into the potential pathways through which these lineages spread globally. Understanding the genomic epidemiology of SARS-CoV-2 in Bulgaria is essential for formulating targeted public health strategies, enhancing vaccination efforts, and effectively managing future outbreaks.

The evolution of the emerging SARS-CoV-2 variants carrying mutations in the spike protein raises concerns about the possibility of accelerated transmission in the ever-evolving COVID-19 pandemic worldwide. AY.4.2, a sublineage of the Delta variant, was considered a variant under investigation (VUI) and also gained the nickname "Delta Plus," due to its extra mutations, Y145H and A222V. In this study, using genomic epidemiology, we provide the first insights into the introduction of AY.4.2 in Bulgaria and the AY.4.2.1 sublineage that found larger dissemination only in Bulgaria and the United Kingdom., (© 2022 Wiley Periodicals LLC.)

Aim: To determine the circulation patterns of measles virus in Bulgaria from 2012 to 2018 after a large measles outbreak in the country (2009-2011)., Methods: Three types of clinical material were collected: serum samples, urine samples, and nasal swabs. Enzyme-linked immunosorbent assay (ELISA) was used to detect specific viral immunoglobulin (Ig) M/IgG antibodies. Viral RNA was extracted from all urine and nasal swabs., Results: In the investigated period, 102 patients were confirmed to have measles (age range: two months to 55 years). A total of 101 samples (99%) were measles-IgM positive. Most of them were detected in 2017 (73%, 74/101), when a measles outbreak in the country was reported. The majority of patients were unvaccinated children aged under 13 months. Out of 101 measles serum samples confirmed by ELISA, 18 (20.45%) were measles-IgG positive and 15 (17.05%) were borderline. Thirty-three positive PCR products were sequenced and genotyped. In 2013, 2016, 2017, and 2018, three different measles viral genotypes were detected: D8, H1, and B3. Most patients were unvaccinated or insufficiently vaccinated., Conclusion: Preventive measures are indispensable to limit the infection in different regions of Bulgaria and its spread to other countries. As vaccination coverage against measles and other vaccine-preventable infections, including SARS-Co2, is low, it is necessary to perform molecular identification of viruses to monitor their circulation and pathogenicity.

Introduction: Mycoplasmagenitalium is an established cause of sexually transmitted infections in men and women. Current guidelines recommend azithromycin and moxifloxacin as first- and second-line treatment, respectively. However, azithromycin treatment failure has been increasingly reported. The aim of this study was to determine the efficacy of azithromycin and alternative antibiotic regimens in a prospective cohort of M.genitalium-positive patients, and macrolide resistance mutations associated with azithromycin failure., (This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

BackgroundQ fever is a zoonosis, included in category B of particularly dangerous infectious agents and as such merits careful surveillance and regular updating of the information about its distribution.AimThis observational retrospective study aimed to provide an overview of Q fever incidence in Bulgaria in the period 2011 to 2017.MethodsAggregated surveillance data from Bulgaria's mandatory surveillance system, laboratory data on individual samples received at the National Reference Laboratory Rickettsiae and Cell Cultures and outbreak reports sent by the regional health authorities to the National Centre of Infectious and Parasitic Diseases, were used in this analysis. Cases were described by year, region, age group and most commonly identified risk behaviours.ResultsA total of 139 confirmed cases were reported in the study period (average annual incidence: 0.27 cases/100,000 inhabitants). No seasonality or trend in reported cases was observed. Cases were mostly sporadic, with two small outbreaks in 2017. Identified risk behaviours among cases were occupational exposure and consumption of milk and dairy products, although exposure data were incomplete. The male/female ratio was 1.4. The identification and resolution of the two rural outbreaks in 2017 with a total of 18 cases involved good practices: active case finding and collaboration between public health and veterinary authorities.ConclusionBetween 2011 and 2017, Bulgaria retained low Q fever incidence, mostly sporadic cases and two small outbreaks. Occupational exposure and consumption of milk and dairy products were the most often reported likely exposures among cases. The outbreak investigations demonstrate the application of good control practices.

In June 2018, in the city of Sofia, Bulgaria, 40 children from four different kindergartens suffered from salmonellosis caused by S. enteritidis. They were reported to have consumed food prepared and delivered by a private catering service. The patients had fever, diarrhea, and some had vomiting and abdominal pain. Sixteen of them were treated in hospital, and the other 24 received home treatment. Some of the outpatients received antibiotic treatment despite WHO recommendations. All 40 isolates were positive for O: D, H: gm and H: m, and were confirmed to be Salmonella enteritidis, respectively. Using conventional and molecular methods, such as serotyping, Multiplex-PCR and PFGE, it was confirmed that the strains were epidemiologically related. Based on molecular genetic methods, we established that the epidemic outbreak had a common origin: contaminated food delivered by a private catering service, which was consumed at all four kindergartens.

We report the first confirmed cases of NDM-1-producing Klebsiella pneumoniae infections in two hospitals in Bulgaria. The isolates were diverse in terms of plasmid and co-resistance gene content. K. pneumoniae PR2682, causing sepsis in patient with polytrauma due to traffic accident, harbored bla NDM-1, bla CMY-4 , bla CTX-M-15 , bla SHV-1 , bla TEM-1b , qnrB, and aac(6')-Ib. bla NDM-1 was transferable by conjugation and located on an IncA/C plasmid of 176-kb, which also carried bla CMY-4 , bla CTX-M-15 , bla TEM-1b , and qnrB. K. pneumoniae PR2830, causing urinary tract infection in prostate cancer patient, harbored bla NDM-1, bla SHV-1 , bla TEM-1 , and aac(6')-Ib. bla NDM-1 was carried on an 86-kb IncA/C plasmid transferable by conjugation together with bla TEM-1 , and aac(6')-Ib. Multilocus sequence typing indicated that the two isolates belonged to sequence type ST11. The emergence of NDM-1-producing K. pneumoniae indicates that bla NDM-1 -mediated resistance is already disseminated among Enterobacteriaceae in Bulgaria. Our results further confirm the role of the Balkans as a secondary reservoir where NDM-encoding genes originate., (Copyright © 2016 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

We report the identification of OXA-48-producing Klebsiella pneumoniae, causing peritonitis in a cancer patient admitted to the Oncology Hospital in Sofia. The isolate had reduced susceptibility to carbapenems but remained susceptible to extended-spectrum cephalosporins. PCR and sequencing confirmed the presence of blaOXA-48 gene flanked by two intact copies of IS1999 on truncated ΔTn1999.1. This transposon was located on unusual non-typeable 29-kb plasmid that could be transferred only by transformation. Multilocus sequence typing (MLST) indicated the presence of the sequence type ST530.This is the first documented infection due to OXA-48-producing Enterobacteriaceae strain in Bulgaria.

During July 2015 a brucellosis outbreak was detected in Kyustendil district, west Bulgaria. As of 15 August, 31 patients have been diagnosed all with an epidemiological connection to Rila town. Patients have not travelled/worked abroad. Breeding family-owned goats and/or improper use of their milk appear to be the main risk factors for transmission of the infection. This second autochthonous brucellosis outbreak in Bulgaria since 2006, affects the western part of the country.

To assess the spread of the Mycobacterium tuberculosis Beijing genotype among patients with multidrug-resistant and extensively resistant tuberculosis in Bulgaria, we genotyped 188 (72%) of 261 microbiologically confirmed resistant isolates obtained during 2007-2011. The estimated prevalence of the Beijing genotype among these patients was 3.2%.

This report describes the first identification of OXA-24 carbapenemase-producing Acinetobacter baumannii isolates from Bulgaria. According to national surveillance data A. baumannii along with Pseudomonas aeruginosa are the most troublesome microorganisms in hospital environment with high rates of acquired carbapenem resistance. In the present study real-time multiplex PCR was performed to identify the most common carbapenemase genes in 15 non-duplicate carbapenem-resistant A. baumannii isolates collected in 2012. The results showed lack of KPC, GES, VIM, IMP-type enzymes. Four A. baumannii isolates tested positive by PCR for the acquired OXA-24 together with the intrinsic OXA-51 carbapenemase. OXA-24 and OXA-23 were determined as co-existent in one isolate. Two isolates were identified with OXA-23 in addition to the OXA-51 carbapenemase.

For the last 60 years, only a few cases of tick-borne encephalitis (TBE) have been detected in Bulgaria. Considering the remarkable increase in TBE morbidity in Europe over the past two decades, we conducted a study of TBE among patients with acute viral meningitis who were hospitalised in Bulgaria during 2009 to 2012. A total of 86 patients with viral meningitis of unknown aetiology during this period were tested. Acute TBE was confirmed in three of these patients. The last TBE case was detected in October 2012; the other two were diagnosed in 2009. To the best of our knowledge, these three patients are the first confirmed TBE cases reported in Bulgaria. The risk of TBE is underestimated in Bulgaria due to the low awareness of medical doctors.

A panel of 29 multidrug-resistant (MDR) Pseudomonas aeruginosa isolates recovered from seven hospitals as part of a country-wide surveillance of antimicrobial resistance in Bulgarian hospitals was studied. Molecular typing through multiple-locus variable number tandem-repeat analysis (MLVA6) yielded 23 different profiles. Phenotypic and genotypic tests for the detection of acquired carbapenemases yielded negative results in all cases. In contrast, 76% of the isolates produced other acquired β-lactamases, including extended-spectrum β-lactamases (ESBLs). Namely, 6 of the isolates (21%) produced a VEB-1 ESBL; 14 (48%) produced an OXA-10-type enzyme (7 OXA-10 and 7 OXA-10 ESBL variants, including 2 OXA-17 [A218G], 2 OXA-74 [C197T, A218G], and 3 OXA-142 [A218G, G470A]); 8 (28%) an OXA-2-type enzyme (all OXA-2); and 1 (3%) a PSE-1 carbenicillinase. Further analysis through multilocus sequence typing (MLST) revealed that the six VEB-1-producing strains, recovered from four hospitals, belonged to ST111 or ST244 international high-risk clones. Additionally, nearly all of the isolates (97%) lacked OprD production, explaining carbapenem resistance. Overexpression of AmpC was documented in 5 (17%) of the isolates, including most of the MDR isolates not producing any acquired β-lactamase. Particularly noteworthy was the very high prevalence of MexXY-OprM overexpression, documented in 72% of the isolates, whereas the prevalence of MexAB-OprM overexpression was lower (21%). In summary, while the production of metallo-β-lactamases is uncommon among P. aeruginosa isolates from Bulgarian hospitals, MDR profiles frequently result from the production of ESBLs combined with the lack of production of the carbapenem porin OprD and the overexpression of the MexXY-OprM efflux pump.

Background: Pneumococcal and Haemophilus influenzae type b (Hib) vaccines were introduced in our national immunisation program in April 2010. The aims of this retrospective, laboratory-based study were to determine the serotypes and antibiotic resistance of Streptococcus pneumoniae and H. influenzae isolates from middle ear fluid (MEF) collected before the introduction of immunization., Methods: S. pneumoniae (n = 128) and H. influenzae (n = 40) strains isolated from MEF of children with AOM between 1994 and 2011 were studied. MICs were determined by a microdilution assay. Serotyping of S. pneumoniae was done by Quellung method and PCR capsular typing was used for H. influenzae. Macrolide resistance genes were detected by PCR for erythromycin resistant S. pneumoniae (ERSP). DNA sequencing of ftsI gene was performed for ampicillin nonsusceptible H. influenzae., Results: The most common serotypes found among children with pneumococcal AOM were 19 F (20.3%), 6B (15.6%), and 19A (10.9%). The potential coverage rates by the PCV7, PCV10 and PCV13 of children aged < 5 years were 63.6%, 66.4% and 85.5%, respectively. Reduced susceptibility to oral penicillin was seen in 68.1%; resistance to erythromycin was 46.9%. We found erm(B) gene in 56.7% of the ERSP, mef(E) gene in 25%; 15% harbored both genes erm(B) + mef(E) and 3.3% had mutations of L4 ribosomal protein. Of the 40 H. influenzae isolates 97.5% were nontypeable. Nonsusceptibility to ampicillin occurred in 25%. Ampicillin resistance groups were: β-lactamase-positive ampicillin resistant (BLPAR) strains (10%), β-lactamase-negative ampicillin resistant (BLNAR) strains (12.5%) and β-lactamase-positive amoxicillin-clavulanate resistant (BLPACR) strains (2.5%). Among BLNAR and BLPACR most of the isolates (5/6) belonged to group II, defined by the Asn526Lys substitution., Conclusions: The levels of antibiotic resistance among S. pneumoniae and H. influenzae causing severe AOM in children are high in our settings. The existence of multidrug-resistant S. pneumoniae serotype 19A is of particular concern. The rate of BLNAR and BLPACR strains among H. influenzae isolates was 15%.

During a recent large tularemia outbreak in Bulgaria we found several cases that were remote from the main focus. One case had an unusual mode of transmission. A hunter acquired tularemia through a nail scratch from a buzzard (Buteo buteo) and consequently developed a typical ulceroglandular form of the disease. The diagnosis was confirmed by serological methods and successful cultivation. Comparative strain typing was performed by high-resolution multi-locus variable-number tandem repeat analysis (MLVA). The isolated strain was identical to one of the outbreak genotypes. We consider that this case represents a bird-to-human transmission of F. tularensis.

Campylobacter is the most commonly reported enteric bacterial pathogen in humans. We still do not have any systematic data concerning campylobacteriosis in Bulgaria. For that reason, we present data of the thermophilic Campylobacter jejuni and Campylobacter coli in the aetiology of diarrhoeal diseases in Sofia, for the period from 1987 to 2008. The study included patients from 0 to over 65 years-old. A total of 51,607 faecal specimens were screened for Campylobacter. C. jejuni and C. coli were detected in 3.58% (1,847) of the strains, with the highest percentage in 1988 (7.5%) and the lowest in 2006 (0.3%). Campylobacteriosis occurred most frequently in the wet months of March, April, May and June, with 105, 102, 124 and 141 cases, respectively, and was rare in January with 25 cases. The most affected groups were children between 0 and 4 years of age (52%) and between five and 14 years of age (30%). Campylobacter infection occurred in 22% of all bacterial gastrointestinal diseases in the city of Sofia during the study period. Salmonella was the most frequently identified pathogen with 32%, followed by Shigella (30%), Campylobacter (22%) and diarrhoeagenic Escherichia coli (16%). The study shows that Campylobacter plays an important role as a bacterial cause of enterocolitis in Sofia, Bulgaria.

Aim: To analyse and present the epidemiological and epizootological situation of brucellosis in humans, sheep and goats caused by Brucella melitensis., Methods: The veterinary health services analyzsd epidemiological reports, as well as other official documents, in relation to the epidemiology and the measures undertaken for control of brucellosis in Bulgaria, 2005-08., Results: In Bulgaria animal infections caused by Brucella melitensis have been eradicated since 1941. In 2005 several Bulgarian citizens with Brucella infection were diagnosed in the National Reference Laboratory. All the cases were imported, mostly by employees on sheep and goat farms in Greece. For a period of four years, the number of infected humans was 120 and distributed in 12 districts. Epidemiological investigations suggested that 45 persons (37.5%) were infected in Greece and 4 in Cyprus, Turkey, Italy and Tanzania respectively. All other patients were considered to be infected in Bulgaria. They were owners of infected sheep and goats or consumers of contaminated dairy products with Brucella melitensis. In June 2006, the first outbreaks of brucellosis in sheep and goat farms were recorded in the Smolyan district. By the end of 2008, the infection was registered in 16 villages of 4 districts. The average prevalence rate in the infected herds was 12.2% in goats and 1.8% in sheep. In order to achieve eradication 496 goats and 117 sheep were slaughtered., Conclusion: A farm where goats from Greece were introduced illegally in 2005 was identified as the primary source of the infection. the negative epidemiological aspects of free movement of goods and persons in the European Union are considered.

In June 2008 an outbreak of gastroenteritis was registered in Sunny Beach resort situated on the Black Sea coast in Bulgaria, affecting 14 employees of a hotel, five of whom tested positive for Salmonella Enteritidis. During June-July 2008 four sporadic S. Enteritidis cases were also reported and two of them were foreign tourists. In the same period S. Enteritidis cases connected with travel to Bulgaria were reported to the European Centre for Disease Prevention and Control (ECDC) from Finland, United Kingdom, Sweden, Germany and Norway. We describe a study performed to find out relatedness between Bulgarian and Finnish S. Enteritidis isolates using phage typing (PT) and pulse-field gel electrophoresis (PFGE). Fifteen S. Enteritidis isolates from Bulgaria and 195 from Finland (including 28 from travellers to Bulgaria) were phage typed. Within Bulgarian isolates four different PTs were found and PT6c with eight strains was predominant. Nineteen out of 28 strains isolated from the Finns visiting Bulgaria belonged also to PT6c. PFGE typing (with one enzyme) of all S. Enteritidis PT6c strains (8 Bulgarian and 19 Finnish isolates) showed indistinguishable PFGE profile. The typing results thus demonstrated a link between Bulgarian and Finnish S. Enteritidis isolates. We conclude that S. Enteritidis PT6c was the cause of salmonella outbreak in Sunny Beach and was exported to Finland, and likely to the United Kingdom, Norway, Sweden and Germany.

Bulgaria had been free from brucellosis since 1958, but during 2005-2007, a reemergence of human and animal disease was recorded. The reemergence of this zoonosis in the country highlights the importance of maintaining an active surveillance system for infectious diseases that will require full cooperation between public health and veterinary authorities.

Q fever is an acute febrile illness due to Coxiella burnetii. In the Balkans, Q fever in humans has been reported since World War II, and in countries such as Bulgaria the number of cases has increased since the early 1990s. We report an investigation of an outbreak in the town of Botevgrad, Western Bulgaria. Overall, 220 cases were identified between May 1 and June 9, 2004. Of the cases, 168 were from Botevgrad; the others were from neighbouring towns. This has been the largest outbreak in Bulgaria in the last 20 years. Q fever outbreaks in urban areas are not common. Flocks of sheep and goats were the most likely source of infection, as suggested by the observation that flocks grazed in, or had travelled on, the roads and the gardens of the town, and for the prevalence of anti-C. burnetii antibodies among animals in the area. This large outbreak highlights how zoonoses such as Q fever may represent a public-health threat also for urban populations.

1,310 Enterobacteriaceae, 242 Pseudomonas aeruginosa and 97 Acinetobacter baumannii clinical isolates collected at a cancer hospital in Bulgaria were screened for the presence of 16S rRNA methylases. The armA methylase gene was identified in 20 (1.5%) Enterobacteriaceae (7 Klebsiella pneumoniae, 3 Escherichia coli, 3 Serratia marcescens, 3 Citrobacter freundii , 3 Enterobacter cloacae and 1 Klebsiella oxytoca). ArmA-mediated aminoglycoside resistance was transferable by conjugation and carried by closely related IncL/M plasmids which also carried ant3"9, dfrXII, sul1, bla(TEM-1), and bla(CTX-M-3) genes encoding resistance to streptomycin-spectinomycin, trimethoprim, sulfonamides, and ss-lactams, respectively. Most of the isolates were genetically different according to PFGE but shared similar restriction patterns of the armA -encoding plasmids. Our findings highlight the strong association of armA and bla(CTX-M-3) extended-spectrum ss-lactamase genes across various species in the family Enterobacteriaceae . The spread of multiresistant isolates expressing 16S rRNA methylases and ESBLs is a worrisome development requiring continuous monitoring.

In this study, cultures of patients with tularemia were evaluated, and antimicrobial susceptibilities of two Francisella tularensis strains were tested by disk diffusion and E-test methods. A high-resolution multiple-locus variable-number tandem repeat analysis (MLVA) comprising six variable-number tandem repeat loci was applied to elucidate the genetic relatedness among Turkish and Bulgarian isolates which were isolated in a recent outbreak. The patients were diagnosed in two outbreaks in two cities of Turkey in 2005 and 2006. A total of 16 samples from 12 patients were cultured, and PCR tests were carried out on 15 samples that were positive in five lymph node aspirates and two soft tissue aspirates. F. tularensis was isolated from the lymph nodes of two patients. Aminoglycosides, quinolones, chloramphenicole, tetracyclines, nitrofurantoin, and rifampicin inhibited growth of the isolates. The Turkish isolates appeared to share a common MLVA pattern with one of the four Bulgarian outbreak genotypes.

The 1997-2005 tularemia outbreak in Bulgaria affected 285 people. Ten strains were isolated from humans, a tick, a hare, and water. Amplified fragment length polymorphism typing of the present isolates and of the strain isolated in 1962 suggests that a new genetic variant caused the outbreak.

This article analyses the distribution of resistant salmonella and resistance mechanisms among the most frequently encountered serotypes in Bulgaria. Culture, biochemical tests and serotyping were used for identification. Screening for resistance to 14 antimicrobial agents with the standard Bauer-Kirbi disk-diffusion method. The double disk synergy method was used to determine production of extended-spectrum a-lactamases (ESBL). Transfer of genes coding for ESBLs with experimental conjugation. Specific primers were used for PCR detection of bla-CTX-M, bla-SHV and bla-TEM. 245 resistant salmonella strains were determined in our study; the majority originated from sporadic cases of human illness or asymptomatic infection and the remaining 23 were isolated from outbreaks. 79 producers of ESBL were detected: 5 S. Enteritidis, 1 S. Typhimurium, 9 S. Isangi and 62 S. Corvallis with types of enzymes: CTX-M3, TEM and SHV. Gene coding for extended-spectrum a- lactamases were successfully transferred into a recipient Escherichia coli C1A strain simultaneously with genes coding for resistance to aminoglycosides and sulphonamides (for bla-CTX-M3) and gene coding for resistance to aminoglycosides and chloramphenicol (for bla-SHVand bla-TEM). PCR amplification revealed bla-CTX-M3 genes in S. Enteritidis, and bla-SHV and bla-TEM in S. Corvallis. Salmonellae have revealed increasing resistance to all clinically important groups of antimicrobial agents. Bulgaria is the first country in the world where ESBL in serotype Corvallis has been reported. A wide diversity of resistance genes is found among the leading serotypes of salmonella causing human disease in Bulgaria.

Background: Trichophyton raubitschekii is a dermatophyte belonging to the T. rubrum complex and is differentiated principally by its positive urease activity and production of profuse macroconidia and microconidia in culture. It is classically isolated from African, South-east Asian and Australian aboriginal patients with tinea corporis or tinea cruris., Objectives: This study was undertaken to screen Greek and Bulgarian clinical isolates identified as T. rubrum for T. raubitschekii and to delineate these strains by two molecular methods used for the first time in T. rubrum epidemiological studies., Methods: Ninety-five Greek and 10 Bulgarian strains, originating from various body sites, initially identified as T. rubrum, were screened for urease activity. The biochemical properties and morphology of the urease-positive strains were determined. Strains were delineated with polymerase chain reaction (PCR)-ribotyping amplifying repeat elements of the intergenic spacer region and by PCR fingerprinting., Results: Five Greek and one Bulgarian T. raubitschekii strains were identified comprising isolates from patients with tinea manuum (one), tinea corporis (one), tinea cruris (one) and tinea unguium (three). Only one strain had the classical T. raubitschekii microscopic morphology, whereas the remaining five presented a dominant arthroconidial phenotype. Both typing methods clustered all T. raubitschekii and T. rubrum isolates together in the same group, indicating strain homogeneity in the genetic regions examined., Conclusions: The reported isolation of T. raubitschekii in the Balkan and South-eastern Mediterranean regions extends the geographical distribution of this species. As the more primitive T. raubitschekii probably represents the parental population of T. rubrum, the Greek and Bulgarian T. raubitschekii strains could represent a remnant of the T. rubrum spread that took place after the First World War, rather than being a recent epidemiological event.

We introduce Bulgarian Surveillance Tracking Antimicrobial Resistance (BulSTAR) and make the first report on surveillance data for 2003. This longitudinal surveillance programme monitors the isolation and antimicrobial susceptibility of all clinically significant microorganisms isolated from blood cultures, cerebrospinal fluid, upper and lower respiratory tract, urine and wound samples in the participating microbiology laboratories. Twenty eight public, 45 hospital and 6 private laboratories from all 28 counties of the Republic of Bulgaria participated in BulSTAR 2003. The total number of isolates from monitored sources during the surveillance period was 98 929. Seven microorganisms represented 72% of all isolated bacteria in BulSTAR 2003: Escherichia coli, Staphylococcus aureus, Proteus-Providencia-Morganella group, Klebsiella spp., Pseudomonas spp, Streptococcus pneumoniae and Streptococcus pyogenes. Generally the resistance of clinically significant Gram positive and Gram negative bacteria in Bulgaria was estimated to be at a medium level when compared with many other surveillance sources worldwide. A unique 32-year experiment on the population by treating all severe infections with an ampicillin/gentamicin combination resulted in twofold higher levels of resistance to amynoglycosides compared with other countries worldwide. This is due to the extremely conservative treatment schemes used in the former socialist countries, based on national directives and cheap domestic production of gentamicin and ampicillin. The forthcoming introduction of a computer network and improvements in detecting mistakes are expected to increase the sensitivity and the significance of BulSTAR surveillance system - an indispensable tool in the combat against increasing worldwide antibiotic resistance.

During the last 40 y, 2 large tularaemia outbreaks occurred in Bulgaria. We report the second outbreak, in 1998--2003, including a total of 262 laboratory confirmed cases. The majority of the patients presented with oropharyngeal tularaemia (89.7%). Less common were the glandular, pulmonary and oculoglandular forms. The diagnosis of tularaemia was confirmed serologically. In 5 cases, F. tularensis was detected by immunofluorescent assay in lymph node biopsies. By PCR, all 5 samples yielded successful amplification of the tul4 gene and the feredoxin gene of F. tularensis. Cultivation of the biopsies resulted in 2 F. tularensis isolates. Three additional F. tularensis isolates were obtained from an open well, a dead hare and a tick. All 5 isolates were identified as F. tularensis subsp. holarctica seu palaearctica. F. tularensis was detected by PCR amplification of the tul4 gene in spleen samples from 9 (21%) of 42 captured rodents. Our study indicated food and water contamination by rodents as important sources of human infection. The high prevalence of the oropharyngeal form of tularaemia supported the assumption that humans contracted the infection by alimentary route.

Geotrichosis affects mainly patients with systemic diseases like diabetes mellitus, leukoses, neoplasms etc. Clinically, it is similar to candidiasis and may occur as an oral, vaginal, skin, or systemic infection. Clinical specimens (98 sputa and 67 oral smears) were collected and studied using microscopic examination of Gram stained preparations and culture sampling between 1995 and 1997. Geotrichum candidum was isolated as a single pathogen in 8 sputum and 7 oral smear samples. Ten-day antifungal treatment with Nizoral was applied and resulted in relatively quick clinical improvement. The presented cases are the first cases of pulmonary and oral infections reported in our home practice in which Geotrichum candidum species was identified as a pathogen. The identification of Geotrichum candidum using combination of colonial and microscopic morphologic features increase the possibilities for diagnostic decision.