<i>In Vitro</i>Antibacterial Activity of Flavonoid Extracts of Two Selected Libyan Algae against Multi-Drug Resistant Bacteria Isolated from Food Products

This study aimed to evaluate the antibacterial activity of flavonoids extracted from two Libyan brown algae namely Cystoseira compressa and Padina pavonica using microwave-assisted extraction method against pathogenic bacteria isolated from meat, meat products, milk and dairy products (Staphylococcus aureus subsp. aureus (5 isolates), Bacillus cereus (3 isolates), Bacillus pumilus (1 isolate), Salmonella enterica subsp. enteric (4 isolates) and Enterohaemor-rhagic Escherichia coli O157 (EHEC O157) (4 isolates)). All of these isolates were muti-drug resistant with high MAR index. The results showed that C. compressa extract exhibited better and stronger antibacterial activities against the seventeen tested isolates with inhibition zones diameter ranged from 14 - 22 mm compared to P. pavonica extract which showed positive effect against 9 isolates with low inhibition zone ranged from 11 - 16.5 mm. Flavonoids extracted from C. compressa also displayed the best spectrum of bactericidal effect with a ratio MBC/MIC ≤ 4 obtained on all susceptible tested bacterial strains. Flavonoids and proanthocyanidins significantly contributed to the antibacterial properties. The mode of action of these active extracts is under investigation.

Prevalence of Thyroid Nodules and Its Relationship with Iodine Status in Shanghai:a Population-based Study

Objective This study was designed to evaluate the prevalence of thyroid nodules（TNs） and its relationship with urine iodine concentrations（UICs） after the regional rapid economic growth and lifestyle changes. Methods A cross-sectional survey was conducted in the general population aged 15-69 years. A questionnaire regarding general and personal characteristics and relevant information was administered. Ultrasonography of the thyroid was performed, and serum triiodothyronine（T3）, tetraiodothyronine（T4）, serum thyroid stimulating hormone（TSH）, free triiodothyronine（FT3）, free tetraiodothyronine（FT4）, thyroglobulin antibody（Tg Ab）, thyroid peroxidase antibody（TPOAb）, and TSH receptor antibody（TRAb） levels were measured for each individual subject. Results The prevalence rates of TNs in the whole population, females and males were 27.76%, 34.04%, and 21.60%, respectively. The prevalence of multiple nodules increased with age, whereas the prevalence peaks differed between males and females. The median UICs in the whole population and females with non-TNs were higher than those of subjects with TNs（P=0.0035, P=0.0068）. The median UICs in subjects with a single TN were higher than those in subjects with multiple TNs（P=0.0164, P=0.0127）. The result showed a U-shaped curve relationship between UIC and prevalence of TNs. The prevalence of TNs was the lowest when the UIC was 140-400 μg/L. Conclusion The prevalence of TNs was nearly 30% and increased with age. The relationship between UIC and prevalence of TNs is U-shaped, with an increase in risk when the UIC was 〈140 μg/L and 〉400 μg/L. Very low or high UIC levels need attention and correction.

Detection of Salmonella typhimurium in retail chicken meat and chicken giblets

Objective:To detect Salmonella typhimurium(S.typhimurium),one of the most frequently isolated serovars from food borne outbreaks throughout the world,in retail raw chicken meat and giblets.Methods:One hundred samples of retail raw chicken meat and giblets(Liver,heart and gizzard)which were collected from Assiut city markets for detection of the organism and by using Duplex PCR amplification of DNA using rfbj andfliC genes.Results:S.typhimurium was detected at rate of 44%,40%and 48%in chicken meat,liver and heart,respectively,but not detected in gizzard.Conclusions:The results showed high incidence of 5.typhimurium in the examined samples and greater emphasis should be applied on prevention and control of contamination during processing for reducing food-borne risks to consumers.

Prevalence and antimicrobial resistance pattern of bacterial strains isolated from patients with urinary tract infection in Messalata Central Hospital, Libya

Objective: To investigate the prevalence of urinary tract infection among patients at Messalata Central Hospital, Libya, to identify the causative bacteria, and to explore their resistance pattern to antimicrobials. Methods: A total number of 1 153 urine samples were collected from patients, who attended daily to Messalata Central Hospital, Libya, in a study extended for one year. Antimicrobial susceptibility testing and isolates typing were done using Phoenix BD(BD diagnostic). Resistance was confirmed manually using agar disk diffusion method. Results: Of the 1 153 urine samples tested, 160(13.9%) samples were positive, from which 17 different, solely Gram negative, uropathogens were identified. Escherichia coli were the most prevalent(55.6%) bacteria, followed by Klebsiella pneumoniae subspecies pneumoniae(16.3%), Proteus mirabilis(6.3%), Pseudomonas aeruginosa(5.6%), Enterobacter cloacae and Klebsiella oxytoca(2.5%, each), Citrobacter koseri and Providencia rettgeri(1.9%, each), Acinetobacter baumannii, Enterobacter aerogenes and Proteus vulgaris(1.3%, each), and Aeromonas caviae, Citrobacter freundii, Cronobacter sakazakii, Enterobacter amnigenus biogroup 2, Pseudomonas putida and Serratia marcescens(0.6%, each). The isolated uropathogens showed increased levels of resistance ranged from 10.5% to 64.5%, with an overall resistance of 28.9%. Amikacin was the most effective antimicrobial followed by Imipenem and Meropenem(0%, 0.6% and 2.5% resistance, respectively); while, Cephalothin and Ampicillin were the least(80.6% and 90.0% resistance, respectively) effective. Conclusions: The obtained results emphasized the emergence of highly resistant bacteria to most of tested antimicrobials and raise the alarm for physicians to change their treatment pattern depending on antimicrobial susceptibility results.

Effects of the viability of Lactobacillus rhamnosus GG on rotavirus infection in neonatal rats

AIM:To study the effects of live and dead Lactobacillus rhamnosus GG(GG) on rotavirus infection in a neonatal rat model.METHODS:At the age of 2 d,suckling Lewis rat pups were supplemented with either live or dead GG and the treatment was continued daily throughout the experi-ment.At the age of 5 and 6 d the pups received oral rotavirus(RV) SA-11 strain.The pups were sacrificed at the age of 7 or 8 d by decapitation.The gastrointestinal tract was removed and macroscopic observations were done.The consistency of feces in the colon was classified using a four-tier system.RV was detected from the plasma,small intestine,colon and feces by real-time quantitative polymerase chain reaction(PCR).RESULTS:In this neonatal rat model,RV induced a mild-to-moderate diarrhea in all except one pup of the RV-inoculated rats.RV moderately reduced body weight development from day 6 onwards.On day 7,after 2 d of RV infection,live and dead GG groups gained significantly more weight than the RV group without probiotics [36%(P = 0.001) and 28%(P = 0.031),respectively].In addition,when compared with the RV control group,both live and dead GG reduced the weight ratio of colon/animal body weight to the same level as in the healthy control group,with reductions of 22%(P = 0.002) and 28%(P < 0.001),respectively.Diarrhea increased moderately in both GG groups.However,the diarrhea incidence and severity in the GG groups were not statistically significantly different as compared with the RV control group.Moreover,observed diarrhea did not provoke weight loss or death.The RV control group had the largest amount of RV PCR-positive samples among the RV-infected groups,and the live GG group had the smallest amount.Rats receiving live GG had significantly less RV in the colon(P = 0.027) when compared with the RV control group.Live GG was also more effective over dead GG in reducing the quantity of RV from plasma(P = 0.047).CONCLUSION:Both live and dead GG have beneficial effects in RV infection.GG may increase RV clearance from the body and reduce colon swelling.

Analysis of temporal trends of human brucellosis between 2013 and 2018 in Yazd Province, Iran to predict future trends in incidence: A time-series study using ARIMA model

Objective:To determine the temporal patterns of cumulative incidence of brucellosis using autoregressive integrated moving average models.Methods:This cross-sectional study employed yearly and monthly data of 1117 laboratory-confirmed human brucellosis cases from January 2013 to December 2018 using the Yazd brucellosis national surveillance system.The monthly incidences constructed a timeseries model.The trend of cumulative incidence was perceived by tracing a line plot,which displayed a seasonal trend with periodicity.Thus,the ARIMA models were selected.Thereafter,Akaike information criteria(AIC)and Bayesian information criterion(BIC)values among different models indicated a preferable model from models which were expanded by diverse lags[(3,0,3),(2,0,3),(3,0,2),(4,0,3)and(3,0,4)].Then,the achieved ARIMA model was applied to the forecasting cumulative incidence of monthly brucellosis incidences.All analyses were performed using Stata,version 11.2.Results:For the ARIMA(3,0,4)model,MAPE value was 56.20%with standard error 0.009–0.016,and white noise diagnostic check(Q=19.79,P=0.975)for the residuals of the selected model showed that the data were completely modelled.The monthly incidences that were fitted by the ARIMA(3,0,4)model,with AIC(25.7)and BIC(43.35)with a similar pattern of actual cases from 2013 to 2018 and forecasting incidences from January 2019 to December 2019 were,respectively,0.50,0.44,0.45,0.49,0.55,0.58,0.56,0.51,0.46,0.44,0.45 and 0.49 per 100000 people.Conclusions:In summary,the study showed that the ARIMA(3,0,4)model can be applied to forecast human brucellosis patterns in Yazd province,supplementing present surveillance systems,and may be better for health policy-makers and planners.

Selection of Lactic Acid Bacteria Isolated from San Simón da Costa Cheese (PDO) in Order to Develop an Autochthonous Starter Culture

Traditional cheeses are an important reservoir of microbial diversity that can have important biotechnological applications, especially with a view to improving the characteristics unique to each type of cheese, and in this respect, starter cultures consisting of autochthonous lactic acid bacteria strains are of particular interest. In the present study, we investigated lactic acid bacteria population diversity in San Simón da Costa cheese (PDO, Galicia, Spain) and found a predominance of the genus Lactobacillus, which by the end of ripening accounted for 78% of the strains isolated in Rogosa agar, around 40% of those in M17 agar and about 10% of those in MSE agar. The main species of lactic acid bacteria identified were Lactococcus lactis subsp. lactis, Lactobacillus casei subsp. casei, Lb. paracasei subsp. paracasei, Leuconostoc mesenteroides and Enterococcus faecalis. Virtually all the strains studied from a technological point of view yielded more than or equal to 0.24 g 100 mL-1 lactic acid. Lactococcus lactis subsp. lactis (SS 194), Lactobacillus paracasei (SS 1695 and SS 1689) and Enterococcus faecalis (SS 1378 and SS 1449) strains exhibited the greatest proteolytic capacity. Based on the overall technological aptitude of the tested strains, we can propose starter cultures and co-cultures that include different combinations of previous strains with a view to manufacturing San Simón da Costa cheese from pasteurised milk.

The environmental influences on the bacteriological quality of red and chicken meat stored in fridges

Objective: To investigate the environmental influences on the bacteriological quality of red and chicken meats on fridges.Methods: The environmental health status was determined by reliable and valid researcher-made checklist.Then 264 samples were gathered in two phases(at the entrance and three months later) and examined for total bacteria count, Escherichia coli,Staphylococcus aureus and Salmonella spp.Results: The result revealed that the mean of total bacteria count, E.coli and S.aureus densities had significant differences in two steps on chicken and the red meat samples(P < 0.05).Among the environmental factors, sanitary status, temperature and personal hygiene had significant effects on total bacteria count and S.aureus densities in chicken samples(P < 0.05), and between wastewater and solid waste disposal with E.coli density in red meat samples(P < 0.05).Conclusions: The results implied that the bacteriological quality of red and chicken meat fluctuates with environmental status(especially temperature, sanitary status and personal hygiene).Regular control, improving of sanitary health, and staff training are necessary for elimination of bacterial contamination.

Spatio-temporal history of H9N2 viruses in Iran and neighbor countries by Bayesian analysis and molecular characterization

Objective: To delineate the H9N2 influenza virus circulation within Iran and its neighboring countries, the potential source of the epidemic in these countries, and its date of origin.Methods: We obtained all hemagglutinin(HA) and neuraminidase(NA) nucleotide sequences of influenza H9N2 available up to December 25, 2020 from Iran and its neighboring countries(i.e., Pakistan, Afghanistan, Turkmenistan, Armenia, Azerbaijan, Turkey, and Iraq). We also performed a Bayesian Markov chain Monte Carlo method to infer the evolutionary dynamic and the most recent common ancestor for the HA and NA sequences.Results: H9N2 epidemic may have started in Iran and Pakistan much earlier than the other investigated countries in the region, and an ongoing bidirectional dispersion of the virus between the investigated countries was also observed. The mean time of the most recent common ancestor of H9N2 viruses was 1988 for HA, and 1992 for NA.Conclusions: Strains from investigated countries rooted in Pakistan and Iran. Regular surveillance of H9N2 viruses, especially in the live bird markets, enhancing the biosecurity of poultry industry and screening newly arriving immigrants and tourists from neighboring countries at border should be considered to control spread of the virus. Furthermore, surveillance of viral molecular evolution should be initiated for effective prevention of epidemic and pandemic spreads.

Probiotic bacteria attenuates cisplatin-induced nephrotoxicity through modulation of oxidative stress, inflammation and apoptosis in rats

Objective: To investigate the effects of probiotic bacteria on cisplatin(CP)-induced nephrotoxicity. Methods: In the present study, 50 Sprague-Dawley rats were used and randomly divided into five groups including control, CP, probiotic bacteria treatment groups with different doses(0.5 and 1 mL) and only probiotic bacteria group. After CP and probiotic administration on seven days, rats sacrificed under anesthesia on the eighth day. The serum urea, creatinine, and blood urea nitrogen levels were analyzed. In renal tissue, malondialdehyde levels, superoxide dismutase and glutathione activity, interleukin-8, interleukin-1β and tumor necrosis factor-alpha levels were determined and histopathological and immunohistochemical changes were also examined. Results: According to results, urea, creatinine and blood urea nitrogen levels as well as kidney weights increased in CP group. Also, CP induced inflammation, oxidative stress, DNA damage and apoptosis in kidney tissue and caused histopathological changes. Administration of the high dose of probiotic bacteria could prevent these changes and damages. Conclusions: This study reveals that probiotic bacteria has protective effects on CP-induced renal damage in rats.

Effects of irradiated Ergosan on the growth performance and mucus biological components of rainbow trout Oncorhynchus mykiss

Effects of irradiated and non-irradiated Ergosan extract(alginic acid) on rainbow trout growth performance and skin mucosal immunity were compared. Ergosan was irradiated at 30 kGy in a cobalt-60 irradiator. A total of 252 fish(128.03±9.4 g) were randomly divided into four equal groups,given the basal diet either unsupplemented with Ergosan(control group) or supplemented with crude Ergosan(5 g/kg),ethanol-extracted Ergosan(0.33 g/kg) or irradiated Ergosan(0.33 g/kg) according to this protocol: basal diet for 15 days,treatment diet for 15 days,basal diet for 10 days and treatment diet for 15 days. Highest growth performance was observed in fish fed irradiated Ergosan(P<0.05). Dietary administration of different Ergosan types did not cause any changes in mucus protein level,but improved alkaline phosphatase level and hemagglutination titer compared with the control(basal diet without Ergosan) on day 55 offeeding trial(P<0.05). Furthermore,the highest value of lysozyme activity was observed in gamma-irradiated Ergosan on day 55. In conclusion,gamma-irradiated Ergosan at 0.33 g/kg was found to improve growth performance and mucus biological components significantly in comparison with the control group(basal diet without Ergosan).

Rate of carcass and offal condemnation in animals slaughtered at Yazd slaughterhouse,central Iran

Objective:To determine the rate of carcass and offal condemnation in the animals slaughtered at Yazd slaughterhouse,Yazd,Iran.Methods:In a nine-month retrospective survey from June 2011 to March 2012,all the carcasses and offal condemnations for large animals(cattle and camels) and small animals(sheep and goats)in Yazd Slaughterhouse were carefully recorded daily.Results:In total,2741 large animals(cattle and camels) and 77515 small animals(sheep and goats) were slaughtered during the period of this survey.Six carcasses(0.21%) of the large animals and 18 carcasses(0.02%) of the small animals were condemned.For large animals,condemnations in summer and autumn were significantly greater than winter(P<0.05).Condemnation rate of liver,lungs and kidneys for the large animals were 5.36%,21.23%and 3.68%respectively and for the small animals were 4.37%,5.46%and 0.51%respectively.The main recorded reasons for carcass condemnations in both large and small animals were icterus and cachexia.The most prevalent lesion resulting in offal condemnation was due to parasitic infection specially metacestods.Conclusions:This study aimed to show the efficiency of documentation records during meal inspection at slaughterhouses to monitor the amount of condemnation and possible approaches to better awareness about the future preventive programs.Considering the percentage of condemnation of carcass and offal in the present study and their price in Iranian markets,the overall economic losses seems to be notable at Yazd slaughterhouse.

Molecular detection of Anaplasma marginale and Anaplasma ovis in sheep and goat in west highland pasture of Iran

Objective:To determine the prevalence of Anaplasma marginale(A.marginale) and Anaplasma ovis from sheep and goat in different highland pasture in west of Iran.Methods:From July 2015 to October 2015,370 blood samples of sheep and goat were collected from different regions in Hamedan province,Iran.The DNA extracted from blood and subsequently,16 S r RNA and MSP4 genes were analyzed by nested-PCR,semi nested-PCR and RFLP methods.Results:In the PCR assessment,overall 27.5%(102/370) of sheep and goat were positive for Anaplasma ovis and A.marginale infection,which was lower than reports from tropical and subtropical regions of Iran.Statistical analysis(the Chi-square test) did not show any significant relation between infection and variables such as location,tick infestation age and sex(P > 0.05).No significant correlation between the altitude and the Anaplasma species infection was found(Mann–Whitney test:P > 0.05).However,Anaplasma infection in goat significantly is more than the sheep(P = 0.008).Conclusions:The ecological changes affect the frequency and distribution of Anaplasma species.Furthermore,our results indicate that sheep as potential reservoirs of A.marginale.

Clostridium difficile in ready-to-eat foods in Isfahan and Shahrekord,Iran

Objective:To determine the prevalence and antimicrobial resistance of Clostridium difficile(C.difficile) isolated from ready-to-eat foods of Iran.Methods:From January to August 2013,a total of 368 unpacked ieady-to-eat food samples were purchased from randomly selected supermarkets,retail stores and restaurants located in Isfahan and Shahrekord,Iran and were evaluated for the presence of C.difficile.Results:C.difficile spores were detected in 5(1.36%) of the 368 samples.The highest prevalence of C.difficile was found in fasl salad(4.29%).followed by yogurt stew(2%),and olovyeh salad(0.93%).All 140 maccaroni salad and I'alafel sandwich samples were negative for C.difficile.One of the five C.difficile isolates(20%) contained tcdA,tcdB and cdtB toxin genes and four strains(80%) contained tcdA.and tcdB toxin genes.Also,among the five C.difficile isolates,only three strains were found to be toxigenic for toxin A and/or B by ELISA.Isolates were susceptible to vancomycin and metronidazole,but variably resistant to other antimicrobial drugs.Conclusions:This study,combined with studies on other food sources,suggests that widespread contamination of food is common.

Effect of virgin olive oil nanoemulsion combined with ajowan(Carum copticum)essential oil on the quality of lamb loins stored under chilled condition

This survey was conducted to evaluate the impact of virgin olive oil nanoemulsion(ONE) combined with ajowan(Carum copticum) essential oil(AEO) on quality of lamb loin under refrigerated condition. The treatments were control, ONE, ONE + 1% AEO, and ONE + 2% AEO. The treatments caused a delay in growth of mesophilic and psychrotrophic bacteria, Enterobacteriaceae, and lactic acid bacteria during chilled storage. The increasing rate of total volatile nitrogen content, lipid and protein oxidation, metmyoglobin formation, and color deterioration was more retarded in treatment groups. The treatments including ONE + 1% AEO and ONE + 2% AEO were more efficient than ONE alone to delay microbial flora growth, slow down oxidative processes, and improve color in the loins. According to the results of microbial, chemical, and sensory parameters, shelflife of lamb loins was 4 days in control, 8 days in ONE, and at least 16 days in ONE + 1% AEO and ONE + 2% AEO groups. In conclusion, combination of ONE and AEO is appropriate as natural preservative to extend the shelflife of lamb loins stored under chilled condition.

Detection of bacterial biofilm in uterine of repeat breeder dairy cows

Objective:To determine the possibility of presence of bacterial biofilm in the uterus of repeat breeder cows and to evaluate the effect of mucolytic agent in cleanup of uterus from biofilm. Methods: Twenty repeat breeder cows were selected from a large commercial dairy farm near Shiraz, Fars province, southern Iran. Uterine secretion samples were collected before and after uterine lavage with dimethyl sulfoxide (DMSO) 10% solution and periodic acid Schiff (PAS) staining was used to detect bacterial biofilm in uterine samples. After sampling, all cows were treated with two doses of PGF2 and intrauterine infusion of Cefquinome sulphate. Artificial insemination (AI) was performed after that.Results: Bacterial biofilms were found in 12 out of 20 animals (60%) in the first sampling with sterile saline lavage (before DMSO) and in 7 cows (35%) after DMSO lavage. Fourteen cows (70%) became pregnant after AI. This evidence showed the presence of bacterial biofilm in the uterus of dairy cows for the first time. Although non-significant, decrease in biofilm detection after DMSO lavage may suggest the potential ability of mucolytic agent for cleaning the uterus from bacterial biofilm. Also, high pregnancy rate after antibiotic treatment in the present study might be attributed to improved effect of antibiotic following lavage of uterine by DMSO.Conclusions:These findings should be investigated in future researches with more sample size.

Prevalence of cryptosporidiosis in animals in Iran: A systematic review and meta-analysis

Objective:To review the prevalence of cryptosporidiosis among animal population of Iran.Methods:Data were systematically gathered from 1 January 2000 to 1 January 2020 in the Islamic Republic of Iran from the following electronic databases:Pub Med,Springer,Google Scholar,Science Direct,Scopus,Web of Science,Magiran,and Scientific Information Database(SID).According to the preferred reporting items for systematic reviews and meta-analyses(PRISMA)and inclusion criteria,88 eligible studies were obtained.Results:The pooled prevalence of cryptosporidiosis using random and fixed effects model according to heterogeneity among animals was as follows:rodents 18.8%(95%CI 12.6%-25.0%),camels 17.1%(95%CI 8.6%-25.7%),cattle 16.8%(95%CI 13.4%-20.1%),goats 14.1%(95%CI 5.2%-23.0%),horses 12.2%(95%CI 8.3%-16.2%),birds 10.5%(95%CI 7.6%-13.4%),sheep 9.9%(95%CI 2.4%-4.9%),cats 8.8%(95%CI 4.8%-12.8%)and dogs 3.7%(95%CI 7.0%-12.8%).Conclusions:Cryptosporidiosis has been reported and present in a wide range of animals in Iran over the years and has a high prevalence in most of these species.

Establishment of probabilistic model for Salmonella Enteritidis growth and inactivation under acid and osmotic pressure

The growth and survival characteristic of Salmonella Enteritidis under acidic and osmotic conditions were studied.Meanwhile,a probabilistic model based on the theory of cell division and mortality was established to predict the growth or inactivation of S.Enteritidis.The experimental results demonstrated that the growth curves of planktonic and detached cells showed a significant difference(p<0.05)under four conditions,including pH5.0+0.0%NaCl,pH7.0+4.0%NaCl,pH6.0+4.0%NaCl,and pH5.0+4.0%NaCl.And the established primary and secondary models could describe the growth of S.enteritis well by estimating four mathematics evaluation indexes,including determination coefficient(R2),root mean square error(RMSE),accuracy factor(Af)and bias factor(Bf).Moreover,sequential treatment of 15%NaCl stress followed by pH 4.5 stress was the best condition to inactivate S.Enteritidis in 10 h at 25◦C.The probabilistic model with Logistical or Weibullian form could also predict the inactivation of S.Enteritidis well,thus realize the unification of predictive model to some extent or generalization of inactivation model.Furthermore,the primary 4-parameter probabilistic model or generalized inactivation model had slightly higher applicability and reliability to describe the growth or inactivation of S.Enteritidis than Baranyi model or exponential inactivation model within the experimental range in this study.

Inactivation of Yersinia enterocolitica in Fermented Sausages during Fermentation

The purpose of this study was to evaluate the storage conditions as a way to increase the safety of fermented sausage, with the specific objectives to investigate the effect of storage time, pH value, water activity and microbiological status （Lactobacillus spp and Enterobacteriaceae） on the levels of Yersinia enterocolitica in fermented sausages. For this experiment, meat was divided into four equal portions of 10 kg each. The first portion was control group （C1 group） without addition of Y. enterocolitica and starter culture. The second portion （CII group） was inoculated starter, the third portion （EI group） was inoculated with I1. enterocolitica and the fourth portion （Eli group） was inoculated Y.. enterocolitica and starter culture. Sampling was performed by randomly selecting two links of each sausage preparation at the 0, 3rd, 6th, 9th, 15th, 25th and 35th day of drying. Results show that Y. enterocolitica and Enterobacteriaceae were not detected after 25 d of storage. The results indicate that practice utilizing starter culture is satisfactory to reduction of pathogen if present. Thus, inclusion with starter cultures in a maturation period may increase the safety of fermented sausages.

Metal Concentration in Muscle Tissue of Carp and Pike from Different Fish Ponds in Belgrade Area

This study was conducted to determine the contamination data of some heavy metals in 10 fish tissue samples of two different fish species---common carp and Northern pike from four different fish ponds and to compare the level of contamination and the differences in the concentration of these elements between these two fish species and between compared fish ponds. In various fish ponds, metal concentrations in the carp muscle tissue varied depending on the metal type. Between compared fish ponds, there were significant differences （P 〈 0.01） in the concentration in muscle carp tissue, except for cadmium. Metal concentrations in the pike muscle tissue also varied among fish ponds, depending on the type of metal. In all compared cases, there were significant differences between metal concentration in pike muscle tissue （P 〈 0.01）. Lead and cadmium concentration in pike muscle tissue were significantly higher （P 〈 0.01, P 〈 0.05, respectively）, and mercury and arsenic concentration were significantly lower （P 〈 0.01） than concentration of this heavy metals in carp muscle tissue in all comapered fish ponds. The results obtained in this study indicate variation in a range of examined metal concentration in muscle tissue, which seems to be typical for the Serbian fish ponds, but is lower than those in rivers with considerable anthropogenic impact.