The Seasonal Activity of Ixodes ricinus Tick in Amol, Mazandaran Province, Northern Iran.

BACKGROUND: The present study aimed to demonstrate the seasonal activities of Ixodes ricinus at the pasture level and on the host. METHODS: A vast pasture in Amol countryside (Mazandaran Province, Iran) which had the potential for a considerable number of cattle and sheep to graze was chosen. Tick sampling from the skin of 130 cattle and 130 sheep were collected every month interval. Simultaneously, the activity of the different stages of I. ricinus on the pasture was considered by dragging method. The collected ticks were placed in jars containing 70% alcohol and sent to the parasitological laboratory for identification. RESULTS: The rate of the infestation with adult I. ricinus in cattle and sheep increases gradually with the beginning of fall and reaches its peak in January, February and March while it starts to decline with the beginning of spring as the infestation rate reach to zero in summer months. Accordingly, the highest number of adult I. ricinus existed on the cattle during January, February, and March. In addition, the results of dragging have been revealed that the active tick population in the pasture exists during November, December, January, and March. CONCLUSION: Ixodes ricinus is regarded a common tick species in Amol (Mazandaran). Due to the biological properties of I. ricinus which is active in the cold and humid months of the year, the prevalence of ruminant infestations with I. ricinus in this area increases from November to March but reaches to zero again with the beginning of summer.

Could Helicobacter pylori play an important role in axonal type of Guillain-Barré syndrome pathogenesis?

In this case-control study, ELISA and Western blot with whole bacterial protein lysate were performed on serum and cerebrospinal fluid (CSF) of 15 controls and 15 patients. According to Griffin subtypes, 10 of our patients were in acute inflammatory demyelinating polyradiculoneuropathy (AIDP) group, 3 in acute motor axonal neuropathy (AMAN) group, and 2 in acute motor sensory axonal neuropathy (AMSAN) subtype. 86.6% of patients were positive for Helicobacter pylori (H. pylori) IgG. Serum anti-H. pylori IgG of patients and controls were significantly different. CSF anti-H. pylori IgG was significantly higher in patients than controls. In patients, the titer of anti-H. pylori IgG in serum was significantly higher than CSF, which may indicate extra-neural antibody synthesis. CSF IgG titer was higher in patients having axonal pattern. Western blot was positive in CSF of 13 patients and negative in all controls. There was a correlation between the number of antibody types against H. pylori particles and the titer of anti-H. pylori IgG in CSF and serum. Also, antibody against cytotoxin associated protein (CagA) was associated with primary axonal pattern. The association between the presence of anti-CagA and primary axonal pattern, is in favor of the relation between axonal neuropathy and H. pylori infection.

Effect of Zataria multiflora Boiss. essential oil on growth and aflatoxin formation by Aspergillus flavus in culture media and cheese.

The effect of Zataria multiflora Boiss. essential oil (EO) against growth, spore production and aflatoxin formation by Aspergillus flavus ATCC 15546 was investigated in synthetic media as well as Iranian ultra-filtered white cheese in brine. EO effectively inhibited radial growth and spore production on potato dextrose agar (PDA) in a dose-dependent manner. At 200 ppm, the radial growth and sporulation reduced by 79.4% and 92.5%, respectively. The growth was completely prevented at EO400 ppm on PDA, and minimum fungicidal concentration (MFC) of the oil was estimated at 1000 ppm. The oil also significantly suppressed mycelial growth and aflatoxin synthesis in broth medium at all concentrations tested (P<0.05). At 150 ppm of EO, the mycelial growth and aflatoxin accumulation reduced by 90% and 99.4%, respectively. The EO at all concentrations tested, had an inhibitory effect against radial fungal growth and aflatoxin production by A. flavus in cheese. However, no concentration of EO examined was able to completely inhibit the growth and aflatoxin production in cheese. The results suggested the potential substitution of the antifungal chemicals by this EO as a natural inhibitor to control the growth of molds in foods such as cheese.

Antibiotic-resistance patterns and frequency of extended-spectrum beta-lactamase-producing isolates of Klebsiella pneumoniae in Tehran.

BACKGROUND: Extended-spectrum beta-lactamase (ESBL)-producing strains of Klebsiella pneumoniae have caused major therapeutic problems worldwide since the majority are resistant to various antibiotics. In this study, an investigation was conducted regarding antibiotic-resistant patterns of 128 isolates of K pneumonile cultured from Iranian patients at two teaching hospitals during 2004-2005. MATERIAL/METHODS: The susceptibility of isolates to 21 antimicrobial agents was determined using the disk diffusion method. Disks containing ceftazidime, cefotaxime, ceftazidime/clavulanic acid, and cefotaxime/clavulanic acid were used in the phenotypic confirmatory (PCT) method to detect ESBL isolates. A comparison between the confirmatory method and double-disk synergy test (aztreonam, ceftazidime, ceftriaxone, cefotaxime, and amoxicillin/clavulanic acid) was also made to assign the appropriate method of detection for ESBLs. The E-test was used to determine the susceptibility of isolates to cefepime. RESULTS: All strains were susceptible to imipenem and meropenem. Resistance to ciprofloxacin and gentamicin were found in 37% (n=47) and 33% (n=42) of isolates, respectively. Production of ESBL was detected in 44.5% of isolates. Resistance to cefepime was found in 40% of isolates. CONCLUSIONS: The prevalence of ESBL strains in the study hospitals is high. The double-disk synergy method is not preferable in successfully detecting ESBL strains. More importantly, 33% of ESBL strains were also resistant to ciprofloxacin and aminoglycosides. Based on the laboratory results, it is recommended that prescription of cephalosporins be restricted to susceptible isolates and that the usage of other effective antibiotics be considered.