In the present study, 10 different ice cream samples available in the markets were collected. They were evaluated of the presence of bacterial load.

Collection of samples
The ice cream samples were collected from the local shops and kept in a frozen state till analysis.

Preparation of sample
The collected sample (1ml) was aseptically transferred in to 9ml sterile distilled water. From this tube, 1ml of the sample were transfered to next dilution tube containing 9ml sterile distilled water. The diutions were processed till 10^-6 dilution. From this dilution, 0.1ml sample was spread on nutrient agar plates to know total cfu/gm of the sample.

Isolation of fungi
Serial diluted 0.1ml ice cream sample was inoculated on the potato dextrose agar (PDA) medium plates and incubated at room temperature for 48 to 72hrs. The intermitted observations were noted for the growth of fungi.

Isolation of bacteria

Isolation of coliforms
A loopful of ice cream sample was streaked on eosin methylene blue (EMB) agar plates for the isolation of coliforms. The plates were incubated at 30°C for 24hrs. The isolated coliforms were further confirmed by using lactose broth.

Detection of Staphylococcus aureus
A loopful of ice cream sample was streaked on the Mannitol salt agar (MSA) media and incubated at 37°C for 24 hrs. The observed was done for the growth of S.aureus.

Detection of Salmonella
Bismuth sulfite agar was used to isolate Salmonella spp. The ice cream samples (2.5g) were transferred into 22.5ml buffered peptone water and it was incubated at 37°C for 12hrs. Each pre-enrichment broth (5ml) was transferred to 10ml of tetrathionate broth and incubated at 42°C for 24hrs. Followed by transferring on sulfite agar and was incubated at 37°C for 24hrs. The plates were examined after 24hrs to 48hrs for typical colonies of Salmonella spp.

Microscope observation
The smears were examined under low power (10x) and then under oil immersion (100x) objectives for size, shape and arrangement of cells.

Motility test
The semisolid agar medium was stabbed with loopful of culture, incubated at 37°C for 24hrs the motility was confirmed by diffused growth of the organism around the stabbed area.

Biochemical tests
IMViC test was performed by using the test culture method.

Indole test
Indole broth was inoculated with the test culture (7ml) and incubated at 37°C for 24hr. The positive test gives a red ring following the addition of Kovac s reagent. The absence of red ring indicates a negative result.

Methyl Red test
MR-VP medium was used for methyl red test. The sterile glucose broth was inoculated with the test culture 7ml and incubated at 37°C for 24hr. Methyl red was added after incubation. Change in colour indicates a negative result.

Voges Prokauer test
The glucose broth was inoculated with the test culture (6ml) and incubated at 37°C for 24 hr. Barrit s reagent was added after incubation, change in colour of the broth from yellow to pink indicates positive results. Negative test gives no colouration.

Citrate utilization test
Simmons citrate agar was used for this test. The test organism was inoculated in Simmons citrate agar slants. The tubes were incubated at 37°C for 24hr. Positive results indicated by the growth of the colonies with blue colouration in the medium. While, negative results showed no growth and the medium was remain green.

Catalase test
A drop of 3% of hydrogen peroxide was placed on a glass slide along with a loopful of culture. The occurrence of brisk effervescence was observed for a positive test.

Oxidase test
A small amount of culture was streaked smoothly on an oxidase disc (Tetra methyl Para Phenylene Diamino Dihydrochloride) with a wire loop. A positive reaction was indicated by an intense deep purple colour appearing with in five to ten seconds.

Rapid urease test broth
Rapid Urease test Broth is used for rapid detection of urease production.

Gelatin hydrolysis test
There are several methods for determining gelatinase production, all of which make use of gelatin as the substrate. The standard and most commonly employed method is the nutrient gelatin stab method. The bacteria were streak on the gelatin stab and incubated at37°C for 24 hours. In positive test, the gelatin hydrolysis was observed in the culture.

Hydrogen sulphide test
This medium contains ferrous ammonium sulfate and sodium thiosulfate, which together serves as indicators for the production of hydrogen sulfide. Hydrogen sulfide production was detected when ferrous sulfide, a black precipitate, was produced as a result of ferrous ammonium sulfate reacting with H₂S gas.

Sugar fermentation test
One drop of culture was inoculated into individual carbohydrate broth tubes and incubated at 37°C for 18-24 hours and observed for color change from blue to yellow due to acidity from fermentation.

Identification of molds from ice cream sample
Dilutions of the sample homogenate were prepared as in standard plated count method. (Saitou and Neil et al., 1987) about 0.1 ml of the diluted sample were plated on the previously solidified Sabouraud´s Dextrose agar medium and spread with asterile L-rod. Then, the plates were incubated at 24°C for 3 days and colonies were observed.

Effect of temperature, pH and salinity on growth of bacterial isolates
All bacterial isolates were inoculated into nutrient broth and maintained at different pH range (pH 5, pH8 and pH9), temperature range (24°C, 40°C and 45°C) and different NaCl concentrations (2%, 5% and 7%). The bacterial growth was monitored after incubation for 24 hr.

Antibiogram of bacterial isolates from ice cream
The Kirby Buure test is a qualitative assay whereby disks of filter paper are impregnated with a single concentration of different antibiotics or any chemicals that will diffuse from the disk into the agar. The gentamycin, streptomycin, norfloxacin, ofloxacin and amoxicillin antibiotic were used in the present study. Antibiotics disks are placed on the surface of agar plate which has already been inoculated with test bacteria. The plates were again incubated for next 24 hr at 37°C. The area of zone of inhibition was measured from the growth culture.