Biofilm formation of Achromobacter xylosoxidans on contact lens.

Achromobacter spp. may contaminate lenses, lens cases, and contact lens solutions and cause ocular infections. The aim of this study was to investigate the possibility of isolated strain of Achromobacter xylosoxidans to form biofilm on the surface of soft contact lenses (CL), to quantify the production of the formed biofilm, and compare it with the reference strains (Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae). Bacterial strain isolated from one contact lens case was identified as A. xylosoxidans using Vitek2 Automated System. Biofilm forming capacity of isolated strain of A. xylosoxidans and reference strains of P. aeruginosa, S. aureus, and H. influenzae on soft CL were analyzed by commonly used microtitre plate method. Our results showed that isolated strain of A. xylosoxidans was capable to form biofilm on the surface of soft contact lens. A. xylosoxidans was strong biofilm producer while all examined reference strains were moderate biofilm producers. A. xylosoxidans appears to be superior biofilm producer on soft CL compared to reference strains.

Methicillin-resistant Staphylococcus aureus biofilm formation on dacryocystorhinostomy silicone tubes depends on the genetic lineage.

PURPOSE: The aim of this study was to investigate biofilm formation on silicone tubes by genetically diverse methicillin-resistant Staphylococcus aureus (MRSA) strains. METHODS: Capacity of biofilm formation on dacryocystorhinostomy silicone tubes was tested on 30 MRSA strains. Identification and methicillin resistance were confirmed by PCR for nuc and mecA genes. Strains were genotypically characterised (SCCmec, agr and spa typing). Biofilm formation was tested in microtiter plate and on silicone tubes. RESULTS: Tested MRSA strains were classified into SCCmec type I (33.3%), II (3.3%), III (20.0%), IV (26.7%) and V (16.7%), agr type I (56.7%), II (36.7%) and III (6.6%), and eight spa clonal complexes (CCs). All tested MRSA strains showed ability to form biofilm on microtiter plate. Capacity of biofilm formation on silicone tubes was as follows: 33.3% of strains belonged to the category of low biofilm producers, and 66.7% to moderate biofilm producers. There was statistically significant correlation between spa CC and the category of biofilm production on silicone tubes (p = 0.01): CC5 and CC45 with moderate amount of biofilm, and CC8 with low amount of biofilm. A moderate amount of biofilm formed on silicone tubes correlated with agr type II MRSA strains (p = 0.008). CONCLUSIONS: Biofilm formation by MRSA on silicone tubes is highly dependent on genetic characteristics of the strains. Therefore, MRSA genotyping may aid the determination of the possibility of biofilm-related ocular device infections. Genotyping and biofilm quantification may be helpful in determining when decolonisation and cohort isolation are required to prevent device-related infections.

[Classical and molecular methods for diagnosis of Chlamydia trachomatis infections].

INTRODUCTION: Genital Chlamydia trachomatis infection is the leading cause of bacterial sexually transmitted diseases in industrial countries, particularly among young people. The consequences of chlamydial infections may involve pelvic inflammatory disease, ectopic pregnancy and tubal factor infertility. METHODS: Available tests for detection of chlamydia in men and women include culture in tissue culture cells, direct immunofluorescence test, enzyme immune assay, nucelic acid probe hibridization and polymerase chain reaction. Nucleic acid amplification tests use different ribonucleic and deoxyribonucleic acid regions as target molecules for amplifying Chlamydia trachomatis ribonucleic/deoxyribonucleic acid in clinical samples. Nucleic acid amplification tests are more sensitive than non-nucleic acid amplification tests. CONCLUSION: Although screening programmes exist in a number of countries, the continuously increasing prevalence of chlamydial infections demonstrates the necessity for defining the best method for the diagnosis and the population for screening.

[Historical and medical review of syphilis-afflicted army leaders, rulers and statesmen].

Syphilis has changed the course of history. It is a sexually transmitted disease caused by spiral-shaped bacterium, Treponema pallidum. The disease has been known under many names during history, and has had a prominent role in history and literature for the last several hundred years. Since its recognition in 15th-century Europe as a new disease, syphilis has been the subject of great mystery and legends. Many believe that syphilis was brought to Europe by Columbus and his sailors, and, thereafter, many famous persons, such as political figures (King Charles VIII, Queen Mary I, Catherine the Great, Paul I, Vladimir Lenin), musicians and literary greats suffered from syphilis. Syphilis is a chronic, multistage disease with diverse and wide-ranging manifestations. Congenital syphilis is of particular concern, where the lack of prenatal testing and antibiotic treatment of infected pregnant women results in congenital infection of the fetus. Syphilis exists even nowadays and according to the World Health Organization estimates, there are 12 million new cases of syphilis occurring each year. While syphilis eradication seems a biologically plausible goal, the major political, cultural, and logistic difficulties involved make it unlikely. Regrettably, rather than becoming an infection of historical significance, syphilis continues to challenge researchers and clinicians in the era of HIV.

[Biology and intracellular life of chlamydia].

INTRODUCTION: Chlamydiae are Gram-negative obligate intracellular bacteria. The developmental cycle of Chlamydiae is specific and different from other bacteria. The elementary body is the infectious form of the organism, responsible for attaching to the target host cell and promoting its entry. The reticulate body is the larger, metabolically active form of the organism, synthesizing deoxyribonucleic acid, ribonucleic acid and proteins. The elementary body and reticulate body represent evolutionary adaptations to extracellular and intracellular environments. INTRACELLULAR PERSISTENCE OF CHLAMYDIA: Predisposition of Chlamydia to persist within the host cell has been recognized as a major factor in the pathogenesis of chlamydial disease. The persistence implies a long-term association between chlamydiae and their host cell that may not manifest as clinically recognizable disease. The ability of chlamydia to remain within one morphological state for a long time in response to exogenous factors suggests an innate ability of these organisms to persist intracellulary in a unique developmental form. Chlamydiae induce interferon gamma and exhibit growth inhibition in their presence. While the high levels of interferon gamma completely restrict the development of chlamydia, its low levels induce the development of morphologically aberrant intracellular forms. The persistent forms contain reduced levels of major outer membrane protein but high levels of chlamydial heat shock protein. CONCLUSION: Immunopathogenesis of chlamydial infection is one of the main focal points of current research into Chlamydia. Chlamydial infections are highly prevalent, usually asymptomatic and associated with serious sequelae. Screening programmes are the most important in the prevention of a long-term sequele.

Ocular rosacea and treatment of symptomatic Helicobacter pylori infection: a case series.

Rosacea is a chronic inflammatory skin disease characterized by recurrent episodes of facial flushing, erythema, papules, pustules, and telangiectasia. More than half of all rosacea patients may have ocular symptoms. Rosacea is associated with certain digestive diseases, such as gastritis, hypochlorhydria, or a number of jejunal mucosal abnormalities, and many patients have Helicobacter pylori infection. The role of Helicobacter pylori has often been a subject of investigation; these studies show conflicting results. Here we present results of the effects of treatment given for H. pylori eradication in seven patients with ocular rosacea that, at the same time, had clinical and serological evidence of H. pylori infection. Six weeks after completion of the treatment, all patients experienced improvement of their rosacea symptoms. Ocular disease responded better than cutaneous rosacea.

Hydrogen peroxide producing lactobacilli in women with vaginal infections.

OBJECTIVE: Hydrogen peroxide producing lactobacilli are isolated from the vaginas of a majority of healthy reproductive age women. Their toxic and inhibitory effect against the overgrowth of pathogens in the vagina is documented by in vitro studies. Clinical studies concerning the role of hydrogen peroxide producing lactobacilli in vaginal infections are controversial. STUDY DESIGN: The aim of this study was to isolate lactobacilli from women with major vaginal infections: bacterial vaginosis (BV), vulvovaginal candidiasis (VVC) and trichomoniasis (TV), and from women with normal flora (NF), to test their ability to produce hydrogen peroxide, to quantitate lactobacilli and to evaluate factors related to the colonization of vagina with hydrogen peroxide producing lactobacilli. The study group comprised 108 women: 27 with VVC, 26 with BV, 20 with TV and 35 with NF. Data was analysed with Fisher exact test, chi2-test, and ANOVA. RESULTS: Lactobacilli were isolated from 81.5% of women with VVC, 58% of women with BV (p=0019), 55% of women with TV (p=0.015) and from 86% of women with NF. The majority of isolates of lactobacilli from women with VVC, TV and NF produced hydrogen peroxide (77%, 63.5% and 80%, respectively), compared with women with BV where only 26.5% of isolates produced hydrogen peroxide (p=0.01). Quantitative analysis showed that in an overwhelming majority of women colonized with lactobacilli, their count was >10(7) CFU/ml. Upon evaluation of behavioural and demographic characteristics, we found that smokers had a lower incidence of isolation of hydrogen peroxide producing lactobacilli (p=0.018). Our results showed that women with BV lack lactobacilli, especially hydrogen peroxide producing ones. Women with TV had a lower rate of lactobacilli. In women with VVC, there was neither significant difference in the isolation of lactobacilli, nor in their ability to produce hydrogen peroxide, compared to women with NF. CONCLUSION: Our results point out that hydrogen peroxide producing lactobacilli could protect against the development of BV, but not against VVC and TV.

Influence of decreased penicillin susceptibility on growth rate of beta haemolytic streptococci.

BACKGROUND & OBJECTIVES: Beta haemolytic streptococci (BHS), especially group A are still highly susceptible to penicillin. One possible explanation for this could be reduced growth capability in penicillin resistant BHS mutants. The present study was therefore undertaken to analyze the growth rates of BHS with decreased susceptibility to penicillin. METHODS: Serial passages in the medium with subinhibitory concentration of penicillin were done to induce resistance to this antibiotic in 12 clinical isolates of BHS serogroups A, B, C, and G. Both penicillin susceptible (parental) and variants with decreased susceptibility to penicillin (laboratory strains) were grown in three different media and their growth rates were determined by counting the number of bacterial colonies and by measuring optical density of bacterial culture. RESULTS: The lowest increase in minimal inhibitory concentration (MIC) value for penicillin (8-16 times) was obtained in BHS group A isolates, while the increase in MIC values of BHS groups B, C and G strains was higher (64-128 times) and they reached the level of complete resistance. Laboratory variants differed significantly from parental in their morphological and cultural characteristics. There were no statistically significant differences between the growth rates of penicillin susceptible and variants with decreased susceptibility to penicillin, though a delay in multiplication of the laboratory strains during exponential phase of growth was noted. INTERPRETATION & CONCLUSION: Though significant differences in phenotypic characteristics of penicillin susceptible and laboratory variants were noted, the results of this study provides no support to the assumption that variants of BHS with decreased susceptibility to penicillin of BHS were incapable for normal growth. Further studies needs to be done to find out the association between the decreased susceptibility to penicillin in the BHS and decreased growth capability in these bacteria.