Marija Gubina

Two- to four-year histological follow-up of gastric mucosa after Helicobacter pylori eradication

In a 2‐ to 4‐year prospective study, the reversibility of gastritis after Helicobacter pylori eradication was analysed. Sixty‐three H. pylori‐positive, chronic duodenal ulcer patients were studied after the successful eradication of bacteria in the period from 1990 to 1993. H. pylori eradication was obtained by triple antimicrobial regimens (colloidal bismuth subcitrate, amoxycillin, and metronidazole) applied for at least 14 days. The criteria for eradication were the absence of bacteria from two antral and two body of stomach biopsies stained with haematoxylin, eosin, and Warthin Starry, and a negative antral biopsy culture. The same diagnostic procedures were repeated, at regular follow‐up endoscopies, each year for up to 4 years. Neutrophil‐granulocyte infiltration of gastric mucosa disappeared in 2 months after bacterial eradication. Mononuclear cellular infiltration was disappearing with statistical significance up to the second year and normal mucosa was observed in the majority of patients in the fourth year of follow‐up. Degeneratively changed lymphoid aggregates were also present in the fourth year in the antrum (12·5 per cent of patients) and in the body of stomach (14 per cent of patients). There was no significant change in antral intestinal metaplasia during the 4 years of follow‐up. Antral atrophy declined significantly in the period from 1 to 3 years of follow‐up. In conclusion, 3–4 years are needed for gastric mucosa to become normal after H. pylori eradication, although some residual lymphoid aggregates persist even after that period. Copyright

Antibacterial tests of Bismuth(III)–Quinolone (Ciprofloxacin, cf) compounds against Helicobacter pylori and some other bacteria. Crystal structure of (cfH2)2[Bi2Cl10]·4H2O

The antibacterial tests of two bismuth(III)-ciprofloxacin (cf) compounds against Helicobacter pylori (H. pylori) and some other bacteria were performed. The results have shown that the activity of both compounds is comparable to that of ciprofloxacin hydrochloride. The crystal structure of (cfH2)2[Bi2Cl10].4H2O (cfH2 = doubly protonated molecule of cf) is presented and discussed. The compound was isolated from acidic medium where quinolone is protonated and thus no bonding between quinolone and bismuth was observed. The bismuth(III) ions are coordinated by chloride ions forming dinuclear [Bi2Cl10]4- anions. The charge of this ion is compensated with protonated quinolone molecules (ionic interactions).

Prevalence and nosocomial spread of methicillin-resistant Staphylococcus aureus in a long-term-care facility in Slovenia.

OBJECTIVES To determine the prevalence and incidence of methicillin-resistant Staphylococcus aureus (MRSA) colonization among residents and healthcare workers (HCWs) of a long-term-care facility (LTCF), to assess possible routes of nosocomial spread, and to determine genetic relatedness of the isolates. SETTING A 351-bed community LTCF for the elderly. DESIGN AND PARTICIPANTS Study investigators made two visits, approximately 3 months apart, to the facility. Samples for cultures were obtained from 107 residents during the first visit, 91 residents during the second visit, and 38 HCWs. RESULTS The prevalence of MRSA colonization among residents was 9.3% during the first visit and 8.8% during the second visit. During the first visit, two HCWs were colonized. During the second visit, no HCWs were colonized. The colonization of HCWs suggested a potential role in the transmission of MRSA. Molecular typing showed that two of three roommates in one room had the same strain, whereas two in another room differed from one another. All isolates, except one, belonged to two related clonal groups. It seems that the clonal group to which most isolates belonged had the greatest potential for spreading among both residents and HCWs. CONCLUSIONS Similar prevalence rates of MRSA colonization have been found in other European countries, but such studies have usually involved residents with better functional status than that of the participants in this study. Nosocomial spread of MRSA occurred in the facility examined, but not frequently. More attention should be focused on the hand hygiene of HCWs.

Are there regional variations in the diagnosis surveillance, and control of methicillin-resistant Staphylococcus aureus?

OBJECTIVE To assess the way healthcare facilities (HCFs) diagnose, survey, and control methicillin-resistant Staphylococcus aureus (MRSA). DESIGN Questionnaire. SETTING Ninety HCFs in 30 countries. RESULTS Evaluation of susceptibility testing methods showed that 8 laboratories (9%) used oxacillin disks with antimicrobial content different from the one recommended, 12 (13%) did not determine MRSA susceptibility to vancomycin, and 4 (4.5%) reported instances of isolation of vancomycin-resistant S. aureus but neither confirmed this resistance nor alerted public health authorities. A MRSA control program was reported by 55 (61.1%) of the HCFs. The following isolation precautions were routinely used: hospitalization in a private room (34.4%), wearing of gloves (62.2%), wearing of gowns (44.4%), hand washing by healthcare workers (53.3%), use of an isolation sign on the patients door (43%), or all four. When the characteristics of HCFs with low incidence rates (< 0.4 per 1,000 patient-days) were compared with those of HCFs with high incidence rates (> or = 0.4 per 1,000 patient-days), having a higher mean number of beds per infection control nurse was the only factor significantly associated with HCFs with high incidence rates (834 vs 318 beds; P = .02). CONCLUSION Our results emphasize the urgent need to strengthen the microbiologic and epidemiologic capacities of HCFs worldwide to prevent MRSA transmission and to prepare them to address the possible emergence of vancomycin-resistant S. aureus.

Risk factors for colonization with methicillin-resistant Staphylococcus aureus in a long-term-care facility in Slovenia

OBJECTIVE To evaluate risk factors associated with methicillin-resistant Staphylococcus aureus (MRSA) colonization in a long-term-care facility (LTCF) for the elderly in Slovenia. SETTING A 351-bed community LTCF for the elderly. DESIGN AND PARTICIPANTS This was a case-control study. MRSA carriage was identified in 102 of 127 residents of the facilitys nursing unit. Two swabs were taken: one from the anterior nares and one from the largest skin lesion. If no skin lesions were present, the axillae and the groin area were swabbed. Data were collected regarding gender, age, length of stay in the facility, underlying conditions, functional status, presence of wounds or pressure sores, presence of catheters, antibiotic treatments, and hospital admissions. RESULTS We detected MRSA in 12 participants. Risk factors independently and significantly associated with MRSA colonization on the multivariate analysis were antibiotic treatments within 1 month before the investigation (odds ratio, 5.087; 95% confidence interval, 1.02 to 25.48; P = .048) and multiple hospital admissions in the 3 months before the investigation (odds ratio, 6.277; 95% confidence interval, 1.31 to 30.05; P = .022). CONCLUSIONS This is the first assessment of risk factors for colonization with MRSA in an LTCF in Slovenia. MRSA poses a problem in this LTCE Our observations may be valuable in implementing active surveillance cultures in infection control programs in Slovenian LTCFs.

Possibility of application of new pneumococcal conjugate vaccines in children in Slovenia.

The emergence of pneumococcal strains resistant to penicillin caused a lot of problems in the therapy of invasive diseases, and added new dimensions to the role of immunisation. In addition to the currently available 23-valent pneumococcal polysaccharide vaccine (PPV) and a new 7-valent conjugate vaccine (PCV) (Prevnar, Wyeth Lederle), two new conjugate vaccines-a 9- and a 11-valent-are being developed. So far, the choice of most appropriate vaccines has depended on the established prevalence of serotypes causing invasive diseases and their antibiotic resistance in the Slovene children population. Between 1993 and 2001, 263 invasive pneumococcal strains isolated from children with invasive diseases were typed. During the period 1998-2001, the same 161 invasive strains were tested for their antibiotic sensitivity. Streptococcus pneumoniae was identified as the major cause of invasive bacterial diseases in the Slovene children population, especially in children under 4 years of age. Distribution by age groups showed the highest incidence in children aged 0-1 years. The predominant serotypes in all age groups were serotypes 14, 1, 19F, 23F, 6B, 18C and 6A. The distribution of penicillin-intermediate and penicillin-resistant strains showed the predominance of serotypes 23F, 14 and 19F. As concerns infection with S. pneumoniae serotypes, we have proved that children aged less than 5 years are more likely to be infected with penicillin-nonsusceptible or intermediate susceptible strains than older children. The 7-valent conjugate vaccine covers 74% of invasive strains in toddlers, but is less effective in older children. We can conclude that the 9-valent vaccine formulation is optimal for our country, but further cost-effectiveness analysis must be done for recommendation of wide use. At that moment it is reasonable to use the 7-valent conjugate vaccine for children with chronic cardiovascular, pulmonary, urinary and liver diseases, with asplenia, neoplasmia, diabetes, meningomyelocoele, before or after bone marrow transplantation and in cases of immunodeficiency.

Diminished Th1-type cytokine production in gastric mucosa T lymphocytes after H. pylori eradication in duodenal ulcer patients

Abstract Helicobacter pylori infects an estimated 50% of the world population, however only a small proportion of individuals develop clinical symptoms of gastritis, peptic ulceration or gastric cancer. The variations in disease presentation may be due to differences in bacterial virulence and/or immune response to the pathogen. In the previous study we reported an increased expression of the IL-2 receptor in duodenal ulcer (DU) patients infected with H. pylori. This study examined intracellular lymphokine production in gastric mucosa infiltrating T lymphocytes in DU patients before and after H. pylori eradication. T lymphocytes were isolated from gastric mucosa biopsies by using mechanical and enzymatic tissue desegregation. Ficoll-purified lymphocytes were incubated with monoclonal antibodies and analysed by using 3-colour flow cytometry analysis for intracellular interferon gamma (IFNgamma) and interleukin 4 (IL-4) expression in order to define Th1 and Th2 cell population. We demonstrated a significant decrease in the proportion of Th1 cells infiltrating gastric mucosa 6 and 12 months after H. pylori eradication. Our results suggest the importance of the local immune response in the development of H. pylori related gastritis.

Cytotoxic T lymphocytes versus streptococcal colonization in periapical granulomas.

Seventeen dental periapical lesions were investigated to study bacterial colonization. Periapical lesions, obtained after apicotomy, were also enzymatically desegregated to quantitatively analyze lymphocyte subpopulations by flow cytometry. Fourteen samples yielded a positive bacterial growth when homogenized and cultured. We isolated enough lymphocytes to make flow cytometric analysis from 12 samples. A significant increase in interleukin-2 receptor and ICAM-1 molecule expression on T cells was found, compared with peripheral blood lymphocytes. Furthermore, a decreased expression of interleukin-2 receptors and HLA DR molecules on CD8+ T cells was found in granulomas predominantly colonized by Streptococcus spp., compared with lesions predominantly colonized by strict anaerobes.

A mouse model of chronic bacterial lesions (a cotton trap) for studying oral bacteria-lymphocyte interactions.

Abstract We established a mouse model of chronic bacterial infection (cotton trap) to get a deeper insight into interactions between immune cells and bacterial strains, that are most commonly isolated from periapical processes. We have used flow cytometry to identify the presence of intracellular cytokines of activated T cells collected from cotton traps, previously infected with different strains of bacteria and implanted subcutaneously into the back of the mice. We provide an evidence that anaerobic bacteria (Bacteroides sp.) and nocardiae are more effective in inducing cytotoxic immunity and Th1 response compared to oral streptococci. Differences in immune response against anaerobic bacteria when compared to streptococci are probably dependent on some non-specific immune cell stimulation (e.g. by bacterial cell wall components), nevertheless the role of specific antigen-dependent immune mechanism can not be excluded.

Meningococcal disease in Slovenia (1993–1999): serogroups and susceptibility to antibiotics

The epidemiology of meningococcal disease was studied prospectively in Slovenia from 1993 to 1999 in children and from 1995 to 1999 in adults. Patients with meningococci isolated from normally sterile body sites were included in the study. Altogether 75 patients (57 children, 18 adults) were found with meningococcal diseases. The overall yearly incidence was 0.43 per 100000 inhabitants. The highest annual incidence (18.5/100000) was found in children between 1 month and 1 year of age. The case to fatality ratio was 4.1%. Group B meningococci were isolated most frequently (84.7%), followed by group C (11.1%). In six patients (8.3%) isolates were less susceptible to penicillin. Four of these were successfully treated with penicillin alone.