Y. Tselentis

Protective effect of exclusive breastfeeding against infections during infancy: a prospective study

Objective To prospectively investigate the effects of breastfeeding on the frequency and severity of infections in a well-defined infant population with adequate vaccination coverage and healthcare standards. Study design In a representative sample of 926 infants, successfully followed up for 12 months, feeding mode and all infectious episodes, including acute otitis media (AOM), acute respiratory infection (ARI), gastroenteritis, urinary tract infection, conjunctivitis and thrush, were recorded at 1, 3, 6, 9 and 12 months of life. Results Infants exclusively breastfed for 6 months, as per WHO recommendations, presented with fewer infectious episodes than their partially breastfed or non-breastfed peers and this protective effect persisted after adjustment for potential confounders for ARI (OR 0.58, 95% CI 0.36 to 0.92), AOM (OR 0.37, 95% CI 0.13 to 1.05) and thrush (OR 0.14, 95% CI 0.02 to 1.02). Prolonged exclusive breastfeeding was associated with fewer infectious episodes (rs=−0.07, p=0.019) and fewer admissions to hospital for infection (rs=−0.06, p=0.037) in the first year of life. Partial breastfeeding was not related to protective effect. Several confounding factors, including parental age and education, ethnicity, presence of other siblings, environmental tobacco smoke exposure and season of birth were demonstrated to have an effect on frequency of infections during infancy. Conclusions Findings from this large-scale prospective study in a well-defined infant population with adequate healthcare standards suggest that exclusive breastfeeding contributes to protection against common infections during infancy regarding and lessens the frequency and severity of infectious episodes. Partial breastfeeding did not seem to provide this protective effect.

Prospective evaluation of effects of broad-spectrum antibiotics on gastrointestinal yeast colonization of humans.

This study evaluated the effects of broad-spectrum antibiotics on the gastrointestinal (G.I.) yeast flora of humans and correlated the findings with those obtained from a mouse model of G.I. colonization by Candida albicans. We prospectively studied 46 adult cancer patients who received one of five broad-spectrum antibiotics (ceftriaxone, ceftazidime, ticarcillin-clavulanic acid, imipenem-cilastatin, and aztreonam) as therapy for infections. Quantitative examination of yeast colonization of stools was conducted at the baseline, at the end of antibiotic treatment, and 1 week after discontinuation of therapy. Antibiotics with anaerobic activity (ticarcillin-clavulanic acid) or high G.I. concentrations (ceftriaxone) caused a higher and more sustained increase in G.I. colonization by yeasts than did antibiotics with poor anaerobic activity (ceftazidime and aztreonam) or a low G.I. concentration (imipenem-cilastatin). These results were similar to those obtained with a mouse model of G.I. colonization by C. albicans that involved the same antibiotics. Hence, the mouse model may be useful for evaluation of yeast colonization of the human G.I. tract.

Evidence for an efflux pump in multidrug-resistant Campylobacter jejuni.

Mechanisms of drug resistance in Campylobacter jejuni were investigated. Mutant strains 34PEFr, which was resistant to pefloxacin (128-fold increase in the MIC), and 34CTXr, which was resistant to cefotaxime (32-fold increase in the MIC) and which was derived from the susceptible parent 34s, were obtained by serial passages on pefloxacin and cefotaxime gradient plates, respectively. Both mutants showed cross-resistance to erythromycin, chloramphenicol, tetracycline, beta-lactams, and quinolones. While the quinolone resistance of strain PEFr could be explained by a mutation at codon 86 of the gyrA gene, the multidrug resistance phenotype of both strains was further investigated. Accumulation of pefloxacin, ciprofloxacin, and minocycline was measured by fluorometry and was found to be lower in the mutant strains than in the parent strain. Preincubation of the cells with carbonyl cyanide m-chlorophenylhydrazone, however, completely abolished this difference. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of outer membrane preparations from both mutant strains showed overexpression of two proteins of 55 and 39 kDa which were absent from the outer membranes of the wild-type strain. These results indicate that in C. jejuni 34PEFr and 34CTXr, multidrug resistance is associated with an efflux system with a broad specificity.

Prospective study of the impact of broad-spectrum antibiotics on the yeast flora of the human gut

The effects of four antibiotics on the yeast flora of the human gut were evaluated. Forty adult cancer patients who received therapy with amoxicillin-clavulanate, ciprofloxacin, sulfamethoxazole-trimethoprim or ampicillin were studied prospectively. Quantitative stool cultures for yeasts were performed immediately before, at the end of and one week after the end of the antibiotic treatment. Amoxicillin-clavulanate caused a higher and more persistent increase in gastrointestinal colonization by yeasts compared to ciprofloxacin, sulfamethoxazole-trimethoprim or ampicillin. The present results are similar to those obtained in a mouse model of gastrointestinal colonization byCandida albicans when the same antibiotics were used.

Epidemiological study of Q fever in humans, ruminant animals, and ticks in Cyprus using a geographical information system

A cross-sectional study of Q fever was conducted in a representative sample of the human and animal population in Cyprus in order to assess the seroprevalence of Q fever and the prevalence of related risk factors. A total of 583 human and 974 ruminant animal serum samples were collected and tested for the detection of antibodies against Coxiella burnetii phase II antigen using an indirect immunofluorescent assay. One hundred forty-one ticks were collected from the infested animals examined; the polymerase chain reaction and the shell-vial technique were used to detect and isolate C. burnetii. Standardized questionnaires were used to obtain information concerning inhabitants and their animals. A geographical information system was used to identify high-risk regions. The prevalence of IgG antibodies against C. burnetii phase II antigen was estimated at 52.7% for humans, 48.2% for goats, 18.9% for sheep, and 24% for bovines. C. burnetii was detected in 11 (7.8%) ticks. Using the geographical information system, two villages were identified as high-risk regions on the basis of high seroprevalence rates of IgG antibodies in humans and animals. Risk factors related to Q fever seropositivity were identified by logistic regression analysis and included age, residence, occupation, use of manure in the garden, ownership of animals (especially goats), and the presence of tick-infested or aborting animals. Q fever poses an occupational hazard to humans living in close contact with sheep and/or goats. In parallel, ticks should be considered an important aspect in the epidemiology of Q fever and should be further studied to better elucidate their role.

Ticks, Tick-Borne Rickettsiae, and Coxiella burnetii in the Greek Island of Cephalonia

Abstract:  Domestic animals are the hosts of several tick species and the reservoirs of some tick‐borne pathogens; hence, they play an important role in the circulation of these arthropods and their pathogens in nature. They may act as vectors, but, also, as reservoirs of spotted fever group (SFG) rickettsiae, which are the causative agents of SFG rickettsioses. Q fever is a worldwide zoonosis caused by Coxiella burnetii (C. burnetii), which can be isolated from ticks. A total of 1,848 ticks (954 female, 853 male, and 41 nymph) were collected from dogs, goats, sheep, cattle, and horses in 32 different localities of the Greek island of Cephalonia. Rhipicephalus (Rh.) bursa, Rh. turanicus, Rh. sanguineus, Dermacentor marginatus (D. marginatus), Ixodes gibbosus (I. gibbosus), Haemaphysalis (Ha.) punctata, Ha. sulcata, Hyalomma (Hy.) anatolicum excavatum and Hy. marginatum marginatum were the species identified. C. burnetii and four different SFG rickettsiae, including Rickettsia (R.) conorii, R. massiliae, R. rhipicephali, and R. aeschlimannii were detected using molecular methods. Double infection with R. massiliae and C. burnetii was found in one of the positive ticks.

Newer macrolides as empiric treatment for acute Q fever infection

ABSTRACT The effectiveness of newer macrolides in acute Q fever for 113 patients was recorded. The mean times to defervescence were 2.9 days for doxycycline and 3.3, 3.9, 3.9, and 6.4 days for clarithromycin, roxithromycin, erythromycin, and β-lactams, respectively (P < 0.01 for macrolides versus β-lactams). We conclude that macrolides may be an adequate empirical antibiotic therapy for acute Q fever.

Carriage of Rickettsia spp., Coxiella burnetii and Anaplasma spp. by endemic and migratory wild birds and their ectoparasites in Cyprus

Three hundred and sixty-eight (368) species of birds (local, endemic and migratory) have been recorded in Cyprus. According to a rough estimate, nearly a quarter of a billion migratory birds fly through the island during the two periods of migration, thus supporting the role of the island as a stopover of great importance. Despite the fact that the role of migratory birds in the transmission of pathogens from the endemic source to Europe has been recognized, the connection between birds, dispersal of ticks infected with medically important pathogens and outbreaks of certain zoonoses remains a hypothesis [1].

In vitro susceptibilities of Brucella melitensis isolates to eleven antibiotics

BackgroundBrucellosis is an endemic disease present in many countries worldwide, but it is rare in Europe and North America. Nevertheless brucella is included in the bacteria potentially used for bioterrorism. The aim of this study was the investigation of the antibiotic susceptibility profile of brucella isolates from areas of the eastern Mediterranean where it has been endemic.MethodsThe susceptibilities of 74 Brucella melitensis isolates derived from clinical samples (57) and animal products (17) were tested in vitro. The strains originate from Crete (59), Cyprus (10), and Syria (5). MICs of tetracycline, rifampicin, streptomycin, gentamicin, norfloxacin, ciprofloxacin, levofloxacin, trimethoprim/sulfamethoxazole, ampicillin, amoxicillin/clavulanic acid, and erythromycin were detected by E-test method. The NCCLS criteria for slow growing bacteria were considered to interpret the results.ResultsAll the isolates were susceptible to tetracycline, streptomycin, gentamicin, ciprofloxacin, norfloxacin, and levofloxacin. Two isolates presented reduced susceptibility to rifampicin (MIC value: 1.5 mg/l) and eight to SXT (MIC values: 0.75–1.5 mg/l). Erythromycin had the highest (4 mg/l) MIC90value and both norfloxacin and erythromycin the highest (1.5 mg/l) MIC50 value.ConclusionBrucella isolates remain susceptible in vitro to most antibiotics used for treatment of brucellosis. The establishment of a standardized antibiotic susceptibility method for Brucella spp would be useful for resistance determination in these bacteria and possible evaluation of bioterorism risks.

Phylogenetic relationships of phlebotomine sandflies inferred from small subunit nuclear ribosomal DNA

Relationships among seventy specimens, fifteen species and three genera of phlebotomines were inferred from the phylogenetic analysis of small subunit nuclear rDNA, obtained by the PCR amplification and cloning of almost full‐length genes. Outgroups included fifteen dipterans, and single representatives of four other insect orders. The more distant the taxa compared, the larger were the regions of ambiguous sequence alignment that needed to be deleted in order to avoid circularity in performing parsimony analyses. Phlebotomine sequences formed a monophyletic clade within the suborder Nematocera, with the progressively more basal sister groups of Diptera being Culicomorpha, Tipulomorpha and the suborder Brachycera. Within Phlebotominae, subgeneric relationships were resolved and the genus Phlebotomus was shown to be monophyletic, but markers for intraspecific geographical populations were not found and intergeneric relationships were not resolved.