Important infectious diseases in the last decade

Despite the remarkable advances in medical research and treatment during the 20th century, infectious diseases remain among the leading causes of death worldwide. In a recent survey by the World Health Organization, three infectious diseases are ranked in the top ten causes of death globally - lower respiratory tract infections (3.1 million deaths; 5.5%), HIV/AIDS (1.5 million deaths; 2.7%) and diarrheal diseases (1.5 million deaths; 2.7%). In low-income and lower-middle income countries, malaria and tuberculosis account for an additional two of the major ten causes of death and during the period 2014-2015 are responsible for 438 000 and 1.5 million deaths, respectively (12). In addition to these, vaccine-preventable childhood diseases, meningitis, sexually transmitted infections (other than HIV), Hepatitis B and C, dengue and tropical disease also contribute significantly to the morbidity and mortality rates associated with infectious diseases (10)

Consumption and in Vitro Resistance to Gentamicin in Problematic Infections in an University Hospital

The aim of this study was to investigate the dynamic of gentamicin resistance in most frequently isolated Gram negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii) and its correlation to the annual gentamicin consumption (DDD per 100 bed-days) during the period 2004 - 2013. The use of gentamicin was constantly increasing during the studied period, which is in correlation with the trend of increasing the rate of gentamicin resistant K. pneumoniae and A. baumannii. Increasing rates of resistance from 28% in 2004 to 39% in 2013, with peak of 48% in 2010 were detected in K. pneumoniae. During the period 2009 - 2012, а sharp rise in the development of gentamicin resistance was detected in А. baumannii: from 58% in 2009 to 78% in 2011. In E. coli, a trend of continuous increasing of gentamicin resistance was found only during the first half of the studied period (2004 - 2007), reaching the rate of 30%. In spite of the increased gentamicin consumption, stabilized rates of gentamicin resistance in E. coli (16-19%) were detected during the second half of the studied period (2008 - 2013).A clear correlation during the studied years `increased consumption - increased resistance rate` was not found for P. aeruginosa, although the general trend for this long period of time is for increasing the gentamicin resistance in this bacterial species (from 25% to 35%)

Molecular epidemiology of multidrug resistant Acinetobacter Baumannii clinical isolates from two Bulgarian hospitals

Objectives: To investigate the molecular epidemiology of multidrug resistant (MDR) Acinetobacter baumannii isolates collected from patients in two Bulgarian Hospitals (H1, H2) during the period 2005-2012.Materials and Methods: A total of 93 nonduplicate MDR A. baumannii isolates collected from Intensive care units (ICUs) and surgical wards were studied. Antimicrobial susceptibility was tested by VITEK 2 (bioMérieux, Marcy l`Etoile) and Phoenix (BD) and the results were interpreted according to the current CLSI guidelines. Detection of carbapenemase encoding genes was performed by PCR. Isolates were genotyped by PFGE and rep-PCR DiversiLab system (bioMerieux) and compared against a library of A. baumannii strains representing the international clones (IC) 1-8.Results: Twenty seven isolates were carbapenem resistant and were associated with OXA-23 and OXA-58 enzymes. The majority of the investigated isolates (n=65) clustered with ICs 1, 2 and 8. Twenty five isolates from H2, collected during the period 2005-2007, did not cluster with any of the representative strains for the ICs 1-8 and formed a separate unique clone, which was found to persist in 2012.Conclusions: Our results reveal the epidemic and endemic potential of A. baumannii as well as persistence of clones over time. Multidrug resistance in A. baumannii from the investigated Bulgarian hospitals was associated with intrahospital dissemination of IC1, 2 and 8 and with unique local clones

Cutaneous aspergillosis in a boy with acute leukemia: the lessons from a `simple` case

Fungal infections are among the most serious infectious complications in immunosuppressed patients. Primary cutaneous aspergillosis is a relatively rare manifestation and is usually described in patients with underlying malignant hematological diseases, AIDS, allogenic stem cell transplantation, solid organ transplantation, etc. We present a clinical case of a 12-year-old boy with acute lymphoblastic leukemia initially diagnosed as primary cutaneous aspergillosis caused by Aspergillus flavus. The retrospective analysis demonstrates that a small solitary pulmonary nodule could be a possible portal of entry. This means that we could consider the disease as an early stage invasive aspergillosis, which is successfully treated with voriconazole

Etiological spectrum and antimicrobial resistance of the most frequently isolated pathogens, associated with urinary tract infections in ambulatory patients

Introduction: Urinary tract infections (UTIs) are among the most common infections both in the community and in the hospital setting.Aim: The aim of this study is to investigate the etiological spectrum and antimicrobial resistance of most frequently isolated pathogens, associated with UTIs in ambulatory patients in Varna city, Bulgaria during a seven-month period (October 2020–April 2021).Materials and Methods: A total of 1600 urine samples, collected from patients with suspected UTIs were tested. Screening for bacterial growth was done by HM&L Uroquattro instrument (ALIFAX, Italy). Species identification and antimicrobial susceptibility testing were performed by VITEK 2 Compact System (bioMerieux) and Kirby-Bauer disk diffusion method.Results: E. coli was the most commonly isolated uropathogen regardless of the age group (48%, n = 61), followed by Enterococcus faecalis (33%, n = 42) and other representatives of order Enterobacterales (13.3%, n = 18). The resistance rates in the group of Gram-negative isolates (n = 79) in decreasing order were as follows: ampicillin, 64.5% > trimethoprim/sulfamethoxazole, 36% > ciprofloxacin, 29.1% > amoxicillin-clavulanic acid, 27.8% > cefuroxime, levofloxacin, 21.5% > fosfomycin, 13.1% > ceftriaxone, 12.6% > ceftazidime, 10.1% > gentamicin, nitrofurantoin, 6.5% > nitroxoline, 4.9%. The resistance rates among the isolates of E. faecalis (n = 42) were as follows: ciprofloxacin, 28.6% > gentamicin, 23.8% > levofloxacin, 19% > nitrofurantoin, 4.7% > amoxicillin, 2.4%. No resistance to meropenem, amikacin, vancomycin, and teicoplanin was found in the studied collection of isolates (n = 127).Conclusion: The etiological spectrum of UTIs in ambulatory patients was dominated by E. coli, followed by E. faecalis. In the group of Gram-negative uropathogens, high resistance rates to ampicillin, trimethoprim/sulfamethoxazole and quinolones were detected. Third-generation cephalosporins, fosfomycin, nitrofurantoin and nitroxoline retained very good activity. Among Enterococcus faecalis isolates, the second most commonly isolated bacterial species, a decreased activity of quinolones was found too, but the aminopenicillins and nitrofurantoin remain highly active

Candida albicans and tooth decay in children with pyelonephritis

Clinical investigations show that alongside Streptococcus mutans, a considerable concentration of Candida albicans is often found in the dental biofilm of toddlers suffering from early childhood caries. Based on some studies, the identification of Candida species in oral cavity is in positive correlation to poor oral hygiene status and abundant carbohydrate consumption. The caries-provoking potential of these species is associated with the acid-producing effect of their heterofermentative characteristics. Candida infection in the oral cavity may be a potential predictor of a tooth decay process in children.The aim of this study is to evaluate the interrelations between Candida albicans and caries in children with diagnosed pyelonephritis.In the investigation are included children with diagnosed pyelonephritis and healthy participants of the same age. Microbiological tests and epidemiological research are performed. Statistical methods are applied.In 4.17% of the patients with the diagnosis of pyelonephritis the test for the presence of Candida albicans in the oral cavity shows positive results. The Pearson`s correlation coefficient examining the indicators of Candida albicans and dft amounts to 0.215. There is a slight positive correlation between these indicators.It can be concluded that these microorganisms are not a definitive predisposing factor for initiation and progression of tooth decay among children with pyelonephritis and healthy controls.Clinical investigations show that alongside Streptococcus mutans, a considerable concentration of Candida albicans is often found in the dental biofilm of toddlers suffering from early childhood caries. Based on some studies, the identification of Candida species in oral cavity is in positive correlation to poor oral hygiene status and abundant carbohydrate consumption. The caries-provoking potential of these species is associated with the acid-producing effect of their heterofermentative characteristics. Candida infection in the oral cavity may be a potential predictor of a tooth decay process in children.The aim of this study is to evaluate the interrelations between Candida albicans and caries in children with diagnosed pyelonephritis.In the investigation are included children with diagnosed pyelonephritis and healthy participants of the same age. Microbiological tests and epidemiological research are performed. Statistical methods are applied.In 4.17% of the patients with the diagnosis of pyelonephritis the test for the presence of Candida albicans in the oral cavity shows positive results. The Pearson`s correlation coefficient examining the indicators of Candida albicans and dft amounts to 0.215. There is a slight positive correlation between these indicators.It can be concluded that these microorganisms are not a definitive predisposing factor for initiation and progression of tooth decay among children with pyelonephritis and healthy controls

Etiological spectrum and susceptibility to antibiotics of the leading bacterial causative agents of acute cholangitis

Комплексният подход към диагностиката и лечението на заболяването остър холангит изисква познаване на спектъра на бактериалните причинители и тяхната чувствителност към антибактериални лекарствени средства. Настоящото проучване представя данни за бактериалните патогени, изолирани от жлъчка на пациенти с остър холангит (ОХ) и тяхната антибиотична чувствителност. Водещи причинители на заболяването са грам-отрицателни бактерии - основно E. coli, изолирани в 26.8% от всички изследвани материали. Сред грам-положителните патогени най-висок е относителният дял на ентерококите (E. feacalis и E. faecium). Най-висока е резистентността на изпитаните бактерии към аминопеницилини - 63.5%. Най-висока in vitro активност демонстрират imipenem, piperacillin / tazobactam, ciprofloxacin и gentamicin с нива на резистентност съответно 2.8%, 14.8%, 14.6% и 15.7%.The complex approach to the diagnosis and treatment of acute cholangitis requires knowledge about the spectrum of involved bacteria and their susceptibility to antibacterial drugs. The study provides information about bacterial pathogens, isolated from bile specimens of patients with acute cholangitis and their in vitro antibiotic susceptibility. The major causative agent of the disease are Gram-negative bacteria - mainly E. coli, presented in 26.8% of all tested samples. Among Gram-positive bacteria, the proportion of enterococci (E. feacalis and E. faecium) is the highest. The highest levels of resistance was detected for aminopenicillins - 63.5%. Imipenem, piperacillin/tazobactam, ciprofloxacin and gentamicin demonstrated the highest in vitro activity with resistance levels 2.8%, 14.8%, 14.6% and 15.7%, respectively

Invitro study of the photodynamic inactivation of cariogenic bacterium Streptococcus mutans - reference strain

Purpose: The aim of this study is to investigate and compare the in vitro antimicrobial effect of 5 photosensitizers: methylene blue(MB), FotoSan® and 3 types of methalphtalocyanines on the reference strain Streptococcus mutans.Materials and methods: A bacterial suspension at a density of 106 cells / ml. is used. An incubation mixture of 1 ml. bacterial suspension (106 Cl./ml.) and the corresponding PS is prepared, achieving a final concentration of PS 1-6 μl. Controls: bacterial suspension in the dark; with irradiation, bacterial suspension + PS in the dark. Sample: bacterial suspension + PS + irradiation. Diode laser with a wavelength of 600 nm is used for irradiation. There are also cultures from controls and samples after preliminary 10-fold dilutions (106; 105; 104; 103; 102;) 6 samples and controls for each tested PS after 24 h incubation at 37º C are reported.Results: The control samples in dark and toxicity only after laser radiation laser show a weak antimicrobial effect. Exception for the Ga(ІІІ)-phtalocyanines-serious dark toxicity. Samples of bacterial suspension + PS + diode laser irradiation showed strong antibacterial effect on St. Mutans with small differences in all tested PSs.Conclusion: The conducted testing demonstrated that the six tested PS show strong antimicrobial effect in the strain reference of S. Mutans, with some small differences between the tested PS

MOLECULAR EPIDEMIOLOGY OF MULTIDRUG RESISTANT ENTEROBACTER CLOACAE BLOOD ISOLATES FROM A UNIVERSITY HOSPITAL

urpose: to evaluate the epidemiological relationship between 3rd generation cephalosporin resistant Enterobacter cloacae blood isolates collected from patients in the University Hospital in Varna city during the period March 2014 and January 2017 and to characterize the ESBLs production in these isolates. Materials and methods: a total of 47 consecutive (nonduplicate) 3rd generation cephalosporin resistant isolates of Enterobacter cloacae, obtained from blood samples of patients admitted in different wards in Varna University Hospital, were investigated. Antimicrobial susceptibility to set of antimicrobial agents was tested by disc diffusion method and Phoenix (BD), and the results were interpreted according to EUCAST guidelines 2017. Identification of ESBL encoding genes was performed by PCR and sequencing. Isolates were genotyped by ERIC PCR. Results: The antimicrobial susceptibility in the whole collection of isolates, shown in decreasing order, is as follows: amikacin, 97.8% < levofloxacin, 76.6% < trimethoprime/ sulphometoxazole, 40.4% < ciprofloxacin, 19% < gentamicin, 8.4% < cefepime, 4.2% < piperacillin/ tazobactam, tobramycin, 2.1%. Multidrug resistance was detected in 70.2% of the isolates. The most widespread enzyme was CTX-M-15, found in 95.5% (n=43). Nine different ERIC types were detected. The dendrogram of similarity revealed three main clones of E. cloacae: Clone I, comprising two closely related subclones (ERIC type A and Aa) (similarity coefficient 0.92), was predominant, detected in Haematology (n=9), Haemodialysis (n=8), ICU (n=6), Cardio surgery (n=3), Pulmonology (n=4) and Gastroenterology (n=1); Clones II (ERIC type C) and III were presented by 5, and 3 isolates with identical profiles, obtained from patients, hospitalized in different wards. The ERIC profiles K, L, M and P, were found in single isolates only and were interpreted as sporadic. Conclusions: multi-drug resistance in E. cloacae was associated with successful intrahospital dissemination of three CTX-M-15 producing E. cloacae clones. Clone I was predominant, demonstrating high cross-transmission, epidemic and invasive potential. BlaCTX-M-15 was identified as a major mechanism of resistance to 3rd generation cephalosporins in E. cloacae

In vitro susceptibility of clinical isolates of Sotrophomonas maltophilia to antimicrobial agents

Цел на настоящата работа е да се проучи чувствителността на 96 клинични изолата S. maltophilia към набор от антимикробни лекарствени препарати. Изолатите са получени от пациенти, хоспитализирани в две университетски болници в България - УМБАЛ „Света Марина` - Варна (n=78) и УМБАЛ `Д-р Георги Странски` - Плевен (n=18) в периода 2007 - 2015г. Чувствителността към десетте изпитвани антибиотика е определена чрез Е-тест, a резултатите са интерпретирани според EUCAST. Антибиотиците с най-добра активност срещу S. maltophilia, респективно с най-ниско ниво на резистентност, са tigecycline (97.92%), trimethoprim/sulfametoxazole (95.84%) и doxycycline (92.71%). Най-високо ниво на резистентност се установява към ticarcillin/clavulanic acid (61.46%), следван от cefatzidime (56.25%) и chloramphenicol (55.21%).The aim of this study was to test the susceptibity of 96 clincal isolates ofS.maltophiliato set of antimicrobial agents. The isolates were collected from patients, hospitalized in two Bulgarian University Hospitals (Varna, n=78 and Pleven, n=18) during the period 2007 - 2015. The antimicrobial susceptibility was studied by E-test and the results were interpreted according to EUCAST. The most active antibiotics (with the lowest level of resistance) were tigecycline (97.92%), trimethoprim/sulfametoxazole (95.84%) and doxycycline (92.71%). The highest rate of resistance was detected for ticarcillin/clavulanic acid (61.46%), followed by cefatzidime (56.25%) and chloramphenicol (55.21%)