Avicenna Journal of Clinical Microbiology and Infection
Volume:2 Issue: 1, Feb 2015

Infection due to Acinetobacter baumannii has become a significant challenge to modern healthcare systems. The rapid emergence and global dissemination of A. baumannii as a major nosocomial pathogen is remarkable and it demonstrates its successful adaptation to the 21st century hospital environment. Recent studies have discussed about essential oil of Origanum vulgare against a range of bacteria, including various species of Staphylococcus, Pseudomonas, Bacillus and Escherichia coli.. The present study aimed to investigate the inhibitory effects O. vulgare essence against multidrug-resistant (MDR) strains of A. baumannii from selected hospitals in Tehran, Iran.. This oil was obtained using the hydrodistillation method and analyzed by gas chromatography mass spectrography (GC/MS). The antimicrobial activity against MDR isolates was achieved using disc diffusion method and macro-broth dilution assay.. Analysis of the essential oil revealed the presence of pulegone (68.59%) piperitone (7.8%), piperitenone (7.8%), 1, 8-cineole (1.3%), and carvacrol (1.6%) as the major components. The results showed a significant activity against MDR A. baumannii with inhibition zones and minimal inhibitory concentration values in the ranges of 7-15 mm and 20-35 µL/mL respectively.. This investigation showed that the essence oil of O. vulgare had a potent antimicrobial activity against MDR A. baumannii. Further research is required to evaluate the practical values of therapeutic applications..

Insects are able to recognize many pathogenic microorganisms and defend against them due to their long evolutionary history. Due to the development of resistance to synthetic antibiotics, researchers are trying to apply insect immune-derived products.. The current study aimed to investigate the antibacterial effect of the American cockroach (Periplaneta americana) hemolymph on susceptible and resistant strains of nosocomial bacteria.. To stimulate adult cockroaches'' immune system, Escherichia coli cells were injected. The antimicrobial effect of the extracted induced and non-induced hemolymph was assayed on many susceptible and resistant pathogenic bacteria.. The comparison of antimicrobial effects of the induced and non-induced hemolymph strains showed that about 43% of bacteria were sensitive to induced hemolymph (P < 0.001), whereas non-induced hemolymph showed no inhibitory effect on the bacteria. Also, evaluation of induced hemolymph effect on the types of strains showed that induced hemolymph affected about 75% of the susceptible bacterial strains (P < 0.001); whereas, it did not affect the resistant strains. Among the tested bacteria, ceftazidime-sensitive E. coli and methicillin-sensitive Staphylococcus aureus showed sensitivity to the induced hemolymph (P < 0.001).. The study results showed that stimulation of the American cockroach’s immunity system lead to production of antibacterial proteins and peptides which had inhibitory effect on the bacteria, depending on the bacterial strains and their sensitivity. Likely this feature of insects can be used as therapeutic strategies to produce natural antimicrobial compounds against the pathogenic bacteria..

Epstein-Barr Virus (EBV) is a member of the Herpesviridae family that has infected more than 90% of the worlds’ population. EBV is now considered etiologically associated with the endemic Burkitt''s lymphoma, Hodgkin disease, and nasopharyngeal carcinoma. Recent findings show the association between EBV infection and other malignancies.. The current study aimed to evaluate the relationship between EBV infection and B-cell lymphoproliferative disorders, including lymphoma and multiple myeloma..Patients and In the current case-control study, a total of 43 patients with lymphoma and multiple myeloma and 46 age/sex-matched healthy people were included. After taking written consent, serum samples were taken from all subjects. The level of IgG against viral capsid antigen was measured using ELISA. Antibody titers > 5 U/mL was considered as positive. Data were analyzed using Stata 11 software.. Of the 89 subjects, 53 were male and 36 females, aged 14 to 82 years. There was no significant difference between EBV seroprevalence in the patients with lymphoma and multiple myeloma, and the healthy subjects.. The results of the current study indicated no relationship between latent EBV infection and lymphoma or multiple myeloma. However, further studies with larger sample sizes are required..

Bacillus species are the predominant soil bacteria because of their resistant-endospore formation and production of essential antibiotics such as bacitracin.. The aim of this study was to isolate Bacillus spp. from riverside soil and investigate their antimicrobial characteristics against some pathogenic bacteria.. Fifty soil samples were collected from different sites of Bahmanshir riverside in Abadan city, Iran, and analyzed for the presence of Bacillus species. The media used in this research were nutrient broth and agar. Bacillus species were identified by their phenotypic and biochemical characteristics. The antimicrobial effects of Bacillus extract against the target bacteria including Escherichia coli, Staphylococcus aureus, Salmonella typhi, Shigella dysenteriae and Corynebacterium diphtheriae were examined.. The identified Bacillus species included B. cereus (86.6%), B. subtilis (6.6%), B. thuringiensis (3.3%), and B. pumilus (3.3%). Evaluation of the antimicrobial activity of the extracted compounds was carried out against five different bacteria. Antibiotic production tests indicated that two Bacillus strains belong to B. cereus, which showed antimicrobial properties. The minimum inhibitory concentrations (MICs) of these compounds ranged between 8.34-33.34 mg/mL for the target bacteria.. This study indicated that some Bacillus species have the potential to produce antimicrobial compounds which can be used to control microbial infections..

Food-borne botulism is one of the potentially fatal forms of food poisoning, usually caused by ingestion of home-canned vegetables, fruits and fish products.. The aim of this study was to report an outbreak of botulism due to homemade doogh in Hamadan, Iran..Patients and During an outbreak, 10 members of a family referred to the hospital because of food poisoning. All patients had a history of consumption of doogh, a traditional drink. After careful physical examination, all of them were hospitalized. Botulism was suspected in all patients except for the first patient.. The first patient was a 76-year-old man who died after 12 hours of admission due to respiratory distress. Nine subsequent patients were diagnosed as botulism with the following symptoms: diplopia (90%), dizziness (70%), nausea and vomiting (80%), ptosis (60%), symmetric weakness of extremities (60%), dysarthria (30%), chest discomfort (30%), mydriasis (20%), dysphasia (20%) and dry mouth (20%). All of the nine patients received botulinum antitoxin and improved during 5-15 days of hospitalization.. Immediate diagnosis based on careful history and physical examination are essential for management of botulism. People should be notified about proper food handling and preparation of traditional homemade foods..

Actinomycetes are one of the most important sources for the production of antibacterial compounds. Marine environments, due to their unique characteristics, are considered a good option to search for bacteria with the capability of producing antimicrobial compounds.. The purpose of this study was to isolate the actinomycetes producing antibacterial compounds.. A total of 35 actinomycetes were isolated from Oman Sea (Lipar Area). To investigate antibacterial activity, the isolated actinomycetes were assessed against reference and pathogenic bacteria, including Staphylococcus epidermidis, Staphylococcu intermedius, Staphylococcu chromogenes, Staphylococcu saprophyticus, Bacillus cereus and methicillin-resistance Staphylococcu aureus, Pseudomonas, Listeria, Klebsiella, Salmonella, Acinetobacter, and Escherichia coli O157:H7, using the cross streak method.. Based on the morphological characterization, 35 isolated cases belonged to actinomycetes and %94 of them had the ability to produce antibacterial compounds. In the cross streak method, most of the isolated bacteria have antibacterial activity against reference S. aureus among Gram-positive bacteria and Acinetobacter among Gram-negative bacteria. Inhibition zone diameters were measured between 2-25 and 1-20 mm for Gram-positive and -negative bacteria, receptivity.. Preliminary results indicate that the native Iranian Actinobacteria could be considered a suitable option for screening of the new antibacterial compounds. Molecular research and antibacterial compound extraction against the aforementioned pathogenic strains are also being conducted..

The polysaccharide intercellular adhesion (PIA) produced by Staphylococcus aureus is effective in the protection of isolates from outer harsh conditions and progress of infection.. The aim of this study was to compare the icaABCD genes encoding polysaccharide intercellular adhesion (PIA) between blood and wound isolates of Staphylococcus aureus (S. aureus) in Tehran..Patients and Forty-eight clinical isolates (including 30 blood and 18 skin wounds) were collected from patients and were identified. Next, mecA gene, SCCmec types and icaABCD genes were detected among blood and wound isolates of S. aureus by PCR assay and specific primers.. Nine (19%) out of 12 methicillin resistant S. aureus (MRSA) isolates harbored SCCmec type III and three (6.2%) isolates harbored SCCmec type V. Prevalence of icaA, icaB, icaC and icaD in blood isolates was twenty-one (70%), fourteen (48%), nineteen (64%) and eighteen (60%), respectively; while the prevalence in wound isolates was as nine (50%), seven (39%), six (34%) and twelve (67%), respectively.. These findings showed no significant difference regarding the presence of icaADBC genes between blood and wound isolates..