فهرست مطالب

  • Volume:8 Issue: 1, 2020
  • تاریخ انتشار: 1399/04/10
  • تعداد عناوین: 7
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  • Ramin Tajbakhsh, Farzaneh Firoozeh* Pages 1-2
  • Ephraim E. Ibadin, Angela Eghiomon, Nosakhare L. Idemudia, Nana A. Anogie, Richard E. Eriamiatoe, Eghonghon I. Dedekumah, Obiorah D. Aguh, Isaac O. Igbarumah, Richard Omoregie* Pages 3-7
    Background

    Serine and zinc type carbapenemases are distributed in many genera of bacteria and are typically associated with specific regions or countries.

    Objectives

    This study phenotypically determined the prevalence of serine and zinc-type carbapenemases among Gram-negative bacilli recovered from clinical specimens in Benin, Nigeria.

    Materials and Methods

    Totally, 158 consecutive non-duplicate bacterial isolates (gram-negative bacilli) recovered from clinical samples were screened for serine and zinc-type carbapenemases using the simplified carbapenemase inactivation (sCIM) and ethylenediaminetetraacetic acid -double-disc synergy test methods.

    Results

    The isolates recovered from clinical specimens included 126 Enterobacteriaceae (79.7%), 7 Acinetobacter spp (3.7%), and 28oxidase positive gram negative bacilli (17.7%). Twenty-eight isolates (17.7%) out of the 158 tested samples were carbapenemase positive. There was no significant difference in the prevalence of serine- and zinc-type carbapenemases (P = 0.0748). However, the prevalence of zinc-type carbapenemase was significantly higher in Pseudomonas aeruginosa compared with other isolates (P = 0.0028) while that of serinetype carbapenemase was not affected by the type of clinical isolates (P = 0.7216). Finally, the prevalence of both serine- and zinc-type carbapenemases were not affected (P > 0.05) by clinical specimens and the source of isolates (in-patient vs. out-patient) respectively.

    Conclusion

    In general, the prevalence of zinc-type (12%) carbapenemases was insignificantly higher than that of serine-type (5.7%) carbapenemases. The measures to reduce infections caused by carbapenemase-producing organisms (CPOs) are advocated accordingly.

    Keywords: Bacteria, Carbapenemase, Serine-, Zinc, Isolates
  • Adel Rezayi, Vadood Razavilar*, Zohreh Mashak, Amirali Anvar Pages 8-14
    Background

    Considering the high fatality of botulism, the control of Clostridium botulinum and its neurotoxins has clinical importance. In this regard, using chemical preservatives, natural essential oils (Eos), and changes in the growth predisposing factors of bacteria are suitable methods to control the growth and toxin producing of C. botulinum in foods.

    Objective

    The current survey was done to assess the effects of Citrus sinensis EO and intrinsic and extrinsic factors on the growth and toxin producing of C. botulinum type A.

    Materials and Methods

    In this experiment with a factorial design, C. sinensis EO (0.0%, 0.015%, 0.03%, and 0.045%), nisin (0, 500, and 1500 IU/mL), nitrite (0, 20, and 60 ppm), pH (5.5 and 6.5), storage temperature (25 and 35°C), and sodium chloride (NaCl, 0.5% and 3%) were used to assess bacterial growth in the brain heart infusion medium. Finally, the mouse bioassay method was also used to assess toxicity.

    Results

    Clostridium sinensis EO with a concentration of 0.045%, as well as the reduction of pH and temperature could significantly delay the growth of bacteria (P ≤ 0.05) in contrast to the use of NaCl and nisin alone. However, all concentrations of sodium chloride (NaCl), nisin, and C. sinensis EO (< 0.045%) in interaction with each other, especially in combination with nitrite, showed good synergistic effects.

    Conclusion

    These results suggested that using certain concentrations of C. sinensis EO and nisin, along with other suboptimal factors caused a significant decrease in the nitrite contents of foods with a significant reduction in the growth and toxin-producing ability of C. botulinum.

    Keywords: Citrus sinensis, Nitrite, Nisin, NaCl, Clostridium botulinum
  • Reza Arjmand, Kumars Porrostami, Seyedeh Sana Esteghamat, Pouria Chaghamirzayi, Parastoo Sharifian, Ehsan Zahmatkesh, Saeed Nikkhah, Mostafa Qorbani, Omid Safari* Pages 15-18
    Background

    Pseudomonas aeruginosa and Acinetobacter baumannii are widely ubiquitous in nature. In addition, they are opportunistic pathogens for humans and the common cause of nosocomial infections.

    Objective

    Due to the increased antibiotic resistance in the treatment of nosocomial infections, this study aimed to evaluate the antibiotic susceptibility pattern of P. aeruginosa and A. baumannii in the pediatrics intensive care unit (PICU).

    Materials and Methods

    Totally, 280 clinical samples from PICU patients were evaluated in this study. The samples were examined for P. aeruginosa and A. baumannii using standard microbiological methods. Finally, the Epsilometer test method was performed to investigate the antibiotic susceptibility pattern of these bacteria.

    Results

    The results revealed a total of 21 isolates (7.5%) of P. aeruginosa and 11 isolates (3.9%) of A. baumannii. P. aeruginosa isolates showed the highest susceptibility to colistin (85.7%) and gentamicin (66.7%) while A. baumannii isolates were more susceptible to colistin (100%), ceftazidime (54.5%), and amikacin (45.5%), respectively.

    Conclusion

    Due to the antibiotic susceptibility patterns of bacterial isolates in the recent study, colistin and gentamicin are recommended for the treatment of P. aeruginosa infections and colistin, ceftazidime, and amikacin are suggested for A. baumannii infections.

    Keywords: Pseudomonas aeruginosa, Acinetobacter baumannii, PICU, Antibiotic resistance, E-test
  • Saeed Khaledian, Mohammadreza Pajohi Alamoti*, Pezhman Mahmoodi Pages 19-24
    Objective

    This study aimed to determine the contamination rate of Staphylococcus aureus in Samosa and falafel as most popular snacks, detect the classic enterotoxins, mecA, and tst genes and investigate antimicrobial resistance in the isolates.

    Materials and Methods

    The samples were examined using bacterial culture and the suspected isolates were characterized by biochemical tests. The identity of S. aureus isolates and the presence of enterotoxin-encoding genes were assessed using a multiplex polymerase chain reaction (PCR) assay and antibiotic resistance of the isolates was determined.

    Results

    The results revealed that 56 (46.67%) samples were contaminated with S. aureus, among which 45 isolates (80.35%) were characterized as enterotoxigenic S. aureus. The highest prevalence rate belonged to sea encoding gene as 20 isolates (35.71%) were positive for this gene followed by sed gene which was detected in 14 S. aureus isolates (25%). Most isolates (75%) were resistant to cefoxitin. Moreover, the results of PCR assays indicated that 10 (17.58%) and 7 (12.5%) isolates were positive for mecA and tst genes, respectively.

    Conclusion

    The results of the present study demonstrated that staphylococcal contamination of Samosa and falafel should be considered as a potential health risk for consumers.

    Keywords: S. aureus, Enterotoxin, Antimicrobial resistance, Samosa, Falafel
  • Razieh Partovi*, Fazeleh Talebi, Amir Babaei, Aghil Sharifzadeh Pages 25-31
    Background

    Active packaging is one of the new packaging technologies which causes interaction between packaging material and food with the aim of food shelf life extension while maintaining food safety and quality. Biodegradable films like polylactic acid (PLA) can be good alternatives to non-biodegradable plastics because of environmental pollution and concerns about the limitations of petroleum resources.

    Objective

    This study was conducted to evaluate the efficacy of PLA film incorporated with marjoram and clove essential oils (EOs) (0.5 and 1% v/v) in maintaining the microbial and chemical quality of minced beef during refrigerated storage.

    Materials and Methods

    Minced beef was packaged with PLA film incorporated with marjoram and clove EOs (0.5 and 1% v/v) alone and in combination and stored at refrigerator temperature for 10 days. Then, microbiological and chemical analyses were done at 0, 2, 4, 7 and 10 days of examination.

    Results

    A reduction of 1 log CFU/g in total count was observed between groups with simultaneous use of EOs and control group (P < 0.05) at day 7; however, there was not any significant difference between the mentioned groups at day 10. Active packaging with marjoram and clove EOs decreased the number of psychrotrophs in comparison to the control group and it was more evident at days 7 and 10. The number of Enterobacteriaceae in control and 1% clove EO/1% marjoram EO groups showed a difference of 3 log units at day 10. TVB-N of 1% clove EO/1% marjoram EO and 0.5% clove EO/1% marjoram EO showed significant differences from control at day 10 (P < 0.05).

    Conclusion

    The results of the current study have shown that the active PLA films can be a promising approach in order to maintain microbial and chemical quality of minced beef at refrigerator temperature for 10 days.

    Keywords: Active packaging, Clove essential oil, Minced beef, Marjoram essential oil, Polylactic acid, Biodegradable film
  • Mehrdad Enami, Mansour Amin, Pejman Shabani*, MohammadReza Gashtil Pages 32-36
    Background

    Common methods for identifying the infectious bacteria in human urine are mainly time-consuming and costly. Therefore, the most reliable method for detecting the urinary tract infections is the urine culture, which requires at least 48 hours to identify infectious factors.

    Objectives

    It is important to detect the bacteria in urine rapidly, simply, and accurately.

    Materials and Methods

    In this work, the variations in the electrical conductivity and dielectric coefficient of the urine sample due to changes in the concentration of infectious bacteria have been studied. Furthermore, an appropriate measurement system was prepared for impedancemetry and conductometry.

    Results

    We showed that the detection time was reduced to about an hour. Finally, the accuracy of the device for diagnosis and precision of measurement were evaluated and compared by the detection method for bacterial culture.

    Conclusion

    In this work, the detection time was reduced to about 1 hour.

    Keywords: Conductometry, Bacteria, Urine, Pathogenic