Yusuf Dogruer

Prevalence of arcobacter species in drinking water, spring water, and raw milk as determined by multiplex PCR.

The aim of this study was to investigate the incidence of Arcobacter species in water sources and raw milk from healthy animals in Kayseri, Turkey. A total of 175 samples of drinking water (n = 100), spring water (n = 25), and raw milk (n = 50) were examined. Arcobacter species were isolated using the membrane filtration technique. Overall, 7 (4%) of the 175 samples yielded Arcobacter spp.: 3 (3%) drinking water samples, 1 (4%) spring water sample, and 3 (6%) raw milk samples. Two species of Arcobacter were recovered from the seven positive samples: Arcobacter butzleri, Arcobacter skirrowii, and A. butzleri plus A. skirrowii found in 3 (1.7%), 2 (1.1%), and 2 (1.1%) samples, respectively. Our study is the first to report the isolation of both A. butzleri and A. skirrowii together from drinking water and is the first report of Arcobacter in milk from healthy cows in Turkey. Based on these findings, the presence of Arcobacter species in environmental waters and raw milk may pose a potential hazard for human health.

Survival of Helicobacter pylori in Turkish fermented sucuk and heat-treated sucuk during production.

The aim of this study was to investigate the survival of Helicobacter pylori during production of sucuk (Turkish fermented sausage). The sucuk mixture was inoculated with H. pylori ATCC 43504 to produce a final level in the mixture of ∼5 × 10(6) CFU/g. Samples in group I were fermented and dried traditionally at 22°C for 7 days. Samples in groups II and III were subjected to the traditional fermentation at 22°C for 3 days. After fermentation, group II samples were fermented and dried at 35°C for 4 days and group III samples were treated with heat until the core temperature reached 65°C. On the first day of fermentation, a 1-log reduction in H. pylori was found in all groups. The H. pylori levels in all groups increased by about 1 log CFU/g by the third day of fermentation and reached the inoculation level. On the fifth and seventh days of fermentation, no appreciable change occurred in the level of H. pylori in groups I and II. After heat treatment, the H. pylori levels were below the level of detection. These results suggest that H. pylori can grow during sucuk fermentation and that a heat treatment should be used during sucuk processing to destroy H. pylori.

Determination of viability in foodborne bacteria with inter-calating dyes: ethidium monoazide (EMA) and propidium monoazide (PMA)

The ability to distinguish between living and dead cells is considered to be very important for biological researches. It is an important problem that the technology used up to day does not allow the quantitative differentiation of specific cells in a mixed cell community. Determination of whether the microorganisms present in the foods are in a viable form is an important phenomenon in determining the disease-forming potential. It is a fact that DNA, which is found in cells that lose their viability, can maintain its activity for a long time. Discrimination of live-dead cell occurs when the intercalating dye is covalently bound to DNA that is cleaved in the dead cell where membrane integrity is impaired. The formation of the covalent bond is activated by photoactivation. Inter-collating dyes only affect dead cells that are damaged by cell wall or membrane integrity. Due to the covalent binding of the inter-collating dye, DNA amplification cannot occur in PCR and other molecular techniques based on PCR. Among the non-permeable stains, it is accepted that PI is the most commonly used. PMA is identical to PI and additionally contains azide groups. Azide groups allow PMA to cross-covalently bond with DNA in bright light. Another inter-collating dyes with an azide group is ethidium mono azide (EMA).The The PMA molecule provides a higher selectivity on discrimination of live-dead cells by virtue of its’ higher charge when compared to EMA. Many researchers have combined EMA and PMA with PCR, Real-time PCR and LAMP in order to differentiate the live population of bacterial, viral, fungal and parasitic food-borne pathogens because they are claimed to be more successful in complex samples than in fluorescence based techniques.