Iranian Journal of Public Health
Year:2003 | Volume:32 | Issue:1|Papers Count:10

The opportunistic pathogen C.albicans is able to cause disseminated infections in immunocompromised patients. Microbiological methods for the diagnosis of invasive candidiasis have many problems including low sensitivity, requirement to invasive clinical sampling such as biopsies or multiple blood cultures and need to expertise laboratory stuff. Since PCR has proven to be a powerful tool in the early diagnosis of several infectious diseases, we applied this approach as a rapid and sensitive method in detection of C.albicans cells in blood samples, for establishment a clinically useful method in diagnosing systemic candidiasis. DNA were extracted from blood samples seeded by serially diluted C.albicans cells, by omitting WBC and RBC followed by enzymatic breaking of fungal cell wall and phenol - chlorophorm extraction and alcohol precipitation of DNA. A new primer pair was designed for PCR-amplification of a part of ribosomal RNA gene. The primer set was able to amplify all medically important Candida species. When PCR was performed for detection of purified DNA, the sensitivity of the method was about 1 picogram fungal DNA, whereas the sensitivity for detection of C.albicans blastospores inoculated in blood was as few as 10 cell per 0.1 ml of blood. This method could be sensitive and useful for early and rapid diagnosis of systemic Candida infections and to simultaneous detection and speciation of Candida species by PCR-RFLP method.

Several authors have indicated that PCP is a toxic chemical and recalcitrant to biodegradation. AOPs is one of the most effective process for degradation of persistent compound. Since the mineralization of recalcitrant compound by AOPs (Advanced Oxidation Processes) often requires long reaction time and strong doses of oxidant, the combination of this process with biological one, considered as an efficient and economic method. In this work degradation of pentachlorophenol in aqueous solution with fenton reagent (H2O +Ferrous ion) was studied. The experiment was done in batch mode, and the initial concentration of PCP was 0.055mM, in pH=3, H2O2=0.6mM, Fe=0.2mM, more than 95% of PCP was degraded in first minute after the reaction was started. Therefore this reaction is very fast and in the initial phase degradation of PCP follows first order kinetics and kineticts constant (K) was 0.026 (S-1). Chloride ion generation as PCP degradation by product was investigated and it was found that the scavenging effect of chloride is negligible. PH and UV215 absorbance analysis, after reaction completion, indicated that generated intermediates have the less chlorinated nature, acidic properties and nonphenolic structure. Chloride ion increases from 0 mg/L to 6 mg/L, pH decreases from 3 to 2.82 and UV215 absorbance decreases from 0.48 to 0.1, therefore it can be resulted that their biodegradability modified and their recalcitrance reduced. In the long time reaction (10hr) experiments, TOC and COD analysis indicated that PCP did not mineralize and TOC and COD reduction was only 20% and 30% respectively. Results from this study indicated that scavenging effects of generated intermediate is important in high doses of H2O2.

Beta-thalassemia, by its high frequency and heterogeneity, constitutes a real problem of health in Iran. About 13 beta globin mutations encompass 70-90% of mutations spectrum in Iran, the rest are rare or unknown. In this study six mutations of the codon IVSI-130(G-C), Frl6 (-C), codon35 (-C), fr23/24(-G), codon8 (+G) and codon 20 (GTG-GAG) were recognized and added to spectrum of beta globin mutations in Iran, using ARMS/PCR and DNA sequencing. Three latter cases are reported for first time.

Giardia is one of the most common human parasites and causes a lengthy course of nonbacterial diarrhea. Disease outbreaks due to Giardia infection are often attributed to contaminated water supplies. A major problem associated with detection for this organism is the lack of sensitive and reliable methods. PCR has the potential to address many of the limitations. We have performed a PCR-based method for sensitive detection of Giardia cysts. Because the sensitivity of PCR is a function of the efficiency of DNA extraction from cysts, we have also compared some different methods for DNA extraction from the cysts. Giardia cysts were collected from infected human, partially purified and serially diluted samples were prepared. DNA was extracted by 3 different methods and we found that simple repeated freezing and thawing was the best method for extraction of DNA from the cysts. A 163 bp conserved fragment related to the giardial heat shock protein (HSP70) gene was used as the target for PCR amplification. We were able to detect as few as 5 cysts in the samples. The results suggest the potential utilities of PCR for sensitive detection of Giardia in water sources.

Infection is one of the cardinal difficulties in the children with acute leukemia and is the leading cause of mortality among them. The prevalence of infection in these patients has several reasons including usage of cytotoxic agents, corticosteriods, broad consumption of antibiotics, duration of confinement in hospital, defective of cellular and humoral Immunity, neutropenia and dysfunction of neutrophils. Despite the fact that intestinal parasitic infection is a rather frequent finding and a health problem in developing countries, in our experience the incidence of helminthic and protozoa infections among children with leukemia was uncommon. Totally 141 patients with leukemia and 70 cases of control group were examined in a period of 12 months, which 40% and 2.8% of former and latter groups, had intestinal pathogen and non-pathogen parasites, respectively. When we compared the frequency of parasitic infection in the control group with the leukemic children, we found no significant difference. It is speculated that parasitic infections may uncommon in these children for numerous reasons such as immunologic and pharmacologic parameters.

Tick-borne diseases like tick-borne relapsing fever are a public health problem in Iran. Its occurrence is more prevalent in north part of country. In order to determine the distribution of soft ticks, Argasidae, and their infection with Borrelia species in Hamadan province, 53 villages were selected randomly. A total of 4805 ticks were collected directly from human dwellings, poultries, and animal shelters. They belong to the genus Argas and Ornithodoros, among which 52.3% were Argas persicus, 2.6% A. reflexus, 2% Ornithodoros canestrinni, 41.4% O. lahorensis, and 1.77% O.tholozani . The most prevalent species was A.persicus and the least one O. lahorensis. Examination of ticks revealed that O. tholozani was infected with Borrelia persica. Infection rate and disease prevalence is coincident in the region. The results will be discussed in more details in terms of preventive measures.

Honey and royal jelly are complex heterogeneous mixtures of flowers" nectar sugars proteins and bees" glandular secretions. Royal jelly is the hypo-pharyngeal gland excretion of the young worker honeybees (Apis mellifera). The wonderful effects of royal jelly on the sexual ability and maturity of the queen has been an interesting topic and controversial issue for researchers for many years. The main purpose of this study was to investigate the anti-bacterial effects of royal jelly against six different bacteria (Escherichia coli, Staphylococcus aureus, Streptomyces griseus, and three unclassified strains of Streptomyces). Four concentrations of water soluble extracts of pure royal jelly were prepared and added drop wise to the bacterial strains seed layer cultured individually. Attempt was made to find out the antibacterial properties of royal jelly by means of agar distribution method (drop-plate). The diameter of the clean zone formed in each concentration was measured and correlated to the ability of the extracts to inhibit the growth of microorganisms. Interestingly the results show inhibitory effects of royal jelly on different strains of the bacteria in-vitro. Ethersoluble and non-soluble fractions of the royal jelly were also examined using the above method. It was found that the antibacterial effect of ether-soluble fraction is substantially higher than the effect of ether non-soluble fraction. The zones formed by ether-soluble fractions of royal jelly in the rout of distribution in agar belong to the potency of anti-bacterial properties of fatty acids present in this fraction of royal jelly (10 -HDA). It was also shown that the non ether-soluble fraction of royal jelly contains a bactericidal substance called royalisin that was found to have potent antibacterial activity. This fraction of royal jelly revealed weaker anti-bacterial effect than the ether-soluble fraction and even of pure royal jelly.

In order to identify the prevalence of parasitic intestinal infections and to determine the impact of some factors, such as age, health houses, education, environmental health etc, on infection, this survey was carried out on 461 stool specimens and scotch tapes obtained from children resident in day-care centers in Damghan city, Semnan province, Iran. The samples were tested using formalin-ether concentration and Graham methods. The analysis of the results showed that at least 68.1 percent of the individuals tested, were infected with one species of pathogen or non-pathogen parasites. The rate of infection for Enterobius vermicularis, Giardia lamblia, Entamoeba histolytica, Ascaris lumbricoides, Hymenolepis nana, Entamoeba coli, Blastocystis hominis, lodamoeba butschlii and Chiloniastix mesnili was 33.8%, 26.2%, 2.4%, 3%, 4.8%, 5.8%, 4.8%, 2.7% and 4% respectively. A significant difference was seen between the rate of infection and parents" education (P<0.005) but was negative regarding age, sex, and health houses. It is concluded that sanitary measurements should be conducted in such centers to decrease the rate of parasitic infection.

Typhoid fever is endemic in Iran. Isolation of S. typhi is a gold standard for diagnosis. Laboratory diagnosis of S. typhi infection relies on serological tests such as the Widal test. This study describes seroprevalence of TO and TH antibody in nonfebrile healthy and febrile with non-typhoid illness. For detection of sensitivity and specificity of Widal test in typhoidal fever diagnosing Widal test was performed on serum specimen of the culture-positive cases of typhoid fever in children aged between 1 and14 years in Tehran, capital of Iran. A cross -sectional study was carried out. Widal tests were performed on 40 healthy nonfebrile children; 40 patients with non typhoidal febrile illness and 58 cases with bacteriologically documented typhoid fever specificity, sensitivity, positive and negative predictive values and the efficacy of the test were determined. Agglutinin titres ? 1:40 were considered normal for TO and TH at 96.25% and 93.75% confidence levels, respectively. Titres above these levels. TO>1:40 and TH>1:40, were considered to be abnormal. 25% of patients showed no response to either agglutinin (TH and TO); and 44.8% of cases shown no response for TO agglutinin. TO >1/320 was not seen in any cases but TH >1/320 was detected in 20.6% of cases. Salmonella typhi TO and H agglutinin titers > 1/40 were considered to be significant with 75.86% sensitivity and 93.75% specificity, respectively. The positive and negative predictive values were 89.79% and 84.26%, respectively.This study suggests that seroprevalence studies in healthy children can help as validate use for particular serological cut-off point.

Pour-Jafari and Farhud reported the fetal deaths and sex ratio among progenies of workers of operating rooms in hospitals of Hamadan (I). Offspring sex ratio in both groups (men and women workers) was lower than in the general population of Hamadan. They concluded that it seems probably, working in operating rooms of hospitals would lead to some genetic consequences. They believed that exposed chronically to waste anesthetic gases, even in low doses, would lead to induction of lethal recessive mutations on X-chromosomes (I).