Short Communication Microbial quality of camels raw milk in by ghkgkyyt


									Emir. J. Food Agric. 2008. 20 (1): 76-83

                                           Short Communication

        Microbial quality of camel's raw milk in central & southern
                    regions of United Arab Emirates
                                       Omer, R. H. and A. H. Eltinay
             School of Food Technology, Faculty of Agricultural Technology and Fish Sciences,
               University of Alneelain , Khartoum, Sudan. 2Department of Food Science and
                  Technology, Faculty of Agriculture Sciences, University of Khartoum

     Abstract: The goals of this study were to assess the possible hazards that might occur as a
     result of consuming camel’s milk fresh, un-pasteurized. The study dealt with the microbial
     quality of camel milk, which includes detection of pathogenic bacteria, enumeration of
     microorganisms (bacteria-yeast-moulds) that may cause changes to the milk, the distribution of
     bacteria in camel milk. The microbial quality of camels raw milk was investigated, 50 samples
     were analyzed for: Aerobic plates count, total coliform, total Staphylococcus aureus total yeast
     and mold. Sixty eight samples were examined for Bacillus cereus, Salmonella spp.,
     Clostridium perfringens, and Listeria monocytogenus. The results indicated that the mean
     value of aerobic plate count 1.8x105cfu/ml, mean value of total coli form 6.8x 101, mean value
     of staphylococcus aureus 1.2x103, yeast mean value 4.1x10-1 cfu/ml. All samples tested for
     pathogenic were negative for Salmonella spp., Clostridium perfringens, and Listeria
     monocytogenus, positive for Bacillus cereus, staphylococcus aureus, and Echerichea coli. The
     distribution of bacteria in camel milk as follow: 43% for gram-positive cocci, 11% for gram-
     negative cocci, 30% for gram negative rods, 23% for gram positive rods, 32% for
     staphylococcus, 15% for yeast.

     Key words: camel milk, microbial quality, U.A.E.

       ‫اﻟﻤﺤﺘﻮى اﻟﻤﻴﻜﺮوﺑﻰ ﻟﺤﻠﻴﺐ اﻻﺑﻞ اﻟﺨﺎم ﻓﻰ اﻹﻗﻠﻴﻢ اﻷوﺳﻂ واﻟﺠﻨﻮﺑﻲ ﻟﺪوﻟﺔ اﻹﻣﺎرات‬
                                   ‫اﻟﻌﺮﺑﻴﺔ اﻟﻤﺘﺤﺪة‬
                                                ‫ر. هـ. ﻋﻤﺮ؛ أ. ح. اﻟﻠﺘﻴﻨﺎي‬
          ‫ﻣﺪرﺳﺔ ﺗﻘﺎﻧﺔ اﻻﻏﺬﻳﺔ، آﻠﻴﺔ اﻟﺘﻘﺎﻧﻪ اﻟﺰراﻋﻴﺔ وﻋﻠﻮم اﻷﺳﻤﺎك، ﺟﺎﻣﻌﺔ اﻟﻨﻴﻠﻴﻦ، ص.ب 70721 اﻟﺨﺮﻃﻮم، اﻟﺴﻮدان‬

     ‫ﻣﻠﺨﺺ: هﺪﻓﺖ اﻟﺪراﺳﺔ ﻟﺘﻘﻴﻢ اﻟﺨﻄﺮ اﻟﺬى ﻗﺪ ﻳﻨﺠﻢ ﻋﻦ ﺗﻨﺎول ﺣﻠﻴﺐ اﻻﺑﻞ اﻟﺨﺎم )أي اﻟﻐﻴﺮ ﻣﻌﺎﻣﻞ ﺣﺮارﻳﺎ( وﺷﻤﻠﺖ دراﺳﺔ‬
     ‫اﻟﻤﺤﺘﻮى اﻟﻤﻴﻜﺮوﺑﻰ، واﻟﻜﺸﻒ ﻋﻦ اﻟﺒﻜﺘﻴﺮﻳﺎ اﻟﻤﺴﺒﺒﺔ ﻟﻺﻣﺮاض وﻣﺪى ﺗﻮاﺟﺪهﺎ ﻓﻰ اﻟﺤﻠﻴﺐ اﻟﺨﺎم، آﺬﻟﻚ ﺗﻮزﻳﻊ اﻟﺒﻜﺘﻴﺮﻳﺎ ﻓﻲ‬
     ‫8 و1 ×501 واﻟﻌﺪ اﻟﻜﻠﻰ ﻟﺒﻜﺘﻴﺮﻳﺎ‬       ‫اﻟﺤﻠﻴﺐ اﻟﺨﺎم و آﺎﻧﺖ اﻟﻨﺘﺎﺋﺞ آﺎﻻﺗﻰ: اﻟﻤﺤﺘﻮى اﻟﻤﻴﻜﺮوﺑﻰ: اﻟﻌﺪ اﻟﻜﻠﻰ اﻟﻤﻴﻜﺮوﺑﻰ‬
     ‫اﻟﻜﻠﻴﻴﻔﻮرم 8 و6 ×101، ﻣﺘﻮﺳﻂ اﻟﻌﺪ اﻟﻜﻠﻰ ﻟﻠﺒﻜﺘﻴﺮﻳﺎ اﻟﻌﻨﻘﻮدﻳﺔ 2 و1×301 ، اﻟﺨﻤﺎﺋﺮ 1 و4×01. اﻟﺒﻜﺘﻴﺮﻳﺎ اﻟﻤﺮﺿﻴﺔ: آﺎﻧﺖ‬
     ‫اﻟﻨﺘﻴﺠﺔ ﺳﺎﻟﺒﺔ ﺑﺎﻟﻨﺴﺒﺔ ﻟﺒﻜﺘﻴﺮﻳﺎ اﻟﺴﺎﻟﻤﻮﻧﻴﻼ واﻟﻜﻠﻮﺳﺘﻴﺮﻳﺪﻳﻮم واﻟﻠﻴﺴﺘﻴﺮﻳﺎ وﻣﻮﺟﺒﺔ ﻟﻠﺒﻜﺘﻴﺮﻳﺎ اﻟﻌﻨﻘﻮدﻳﺔ واﻟﺒﺎﺳﻴﻠﺲ واﻻﻳﺸﺮﻳﺸﻴﺎ‬
     ‫آﻮﻻي. ﺗﻮزﻳﻊ اﻟﺒﻜﺘﻴﺮﻳﺎ ﻓﻰ اﻟﺤﻠﻴﺐ اﻟﺨﺎم: آﺎﻧﺖ ﻧﺴﺒﺔ اﻟﻌﺰل اﻟﻤﻴﻜﺮوﺑﻰ ﻣﻦ74 ﻋﻴﻨﺔ آﺎﻻﺗﻰ: 34 % آﺮوﻳﺔ ﻣﻮﺟﺒﺔ ﻟﺼﺒﻐﺔ‬
     %32 ،‫ﺟﺮام، 11% ، آﺮوﻳﺔ ﺳﺎﻟﺒﺔ ﻟﺼﺒﻐﺔ ﺟﺮام، 03% ﻋﺼﻮﻳﺔ ﺳﺎﻟﺒﺔ ﻟﺼﺒﻐﺔ ﺟﺮام ، 32% ﻋﺼﻮﻳﺔ ﻣﻮﺟﺒﺔ ﻟﺼﺒﻐﺔ ﺟﺮهﻢ‬
                                                                                             .‫ﺑﻜﺘﻴﺮﻳﺎ ﻋﻨﻘﻮدﻳﺔ، 51% ﺧﻤﺎﺋﺮ‬

                                             .‫آﻠﻤﺎت ﻣﻔﺘﺎﺣﻴﺔ: ﺣﻠﻴﺐ اﻻﺑﻞ ،اﻟﻤﺤﺘﻮى اﻟﻤﻴﻜﺮوﺑﻰ، دوﻟﺔ اﻻﻣﺎرات اﻟﻌﺮﺑﻴﺔ اﻟﻤﺘﺤﺪة‬

Omer, R. H. and A. H. Eltinay
Introduction                                        proteinase production, which was
                                                    reduced by higher concentrations of
    Milk is an ideal habitat for the growth         glucose.
and multiplication of microorganisms due                Farah, (1993) reviewed the ability of
to its nutritional constitution which               camel milk to inhibit growth of
contain protein, carbohydrate, mineral              pathogenic bacteria and it’s relations to
and vitamins. All these components                  whey lysozyme. Twenty of 200 samples
support the growth of many forms of                 collected from individual camels
bacteria. A raw milk aseptically drawn              inhabited growth of one or more of six
from a healthy animal usually contains a            pathogenic test organisms. The milk
few bacteria (Frazler, 1967). Beside that           samples with inhibition properties scored
milk is an ideal medium for the                     zero in the California mastitis test. The
growth      of    microorganisms from               lysozyme content of the twenty samples
surrounding environment (Cousins and                showing growth inhibition was 648
Barmley, 1981). The microbial quality of            µg/100ml which is significantly higher
camel’s raw milk in Riyadh City was                 than the average in the 38 samples (62.8
investigated by Al–Mohizea (1986) who               µg/100ml) that has no inhibitory effect.
found the aerobic plate count exceeded              Duhaiman (1988) purified camel milk
10 cfu/ml in 13 samples and averaged                lysozyme and separated it from
2.2x105cfu/ml. All samples tested were              lactoferrin and a low molecular weight
found to contain coli form in excess of             protein. The Lytic effect of camel milk
10/ml with an average of 5.1x105cfu/ml.             lysozyme was assayed using Escherichia
Coagulate      positive     Staphylococcus          coli and Micrococcus lysodeikticus and
aureus was detected in all samples with             its activity was compared with that of
an average of 1.3x103cfu/ml. Salmonella,            lysozyme from human milk and egg
Bacillus      cereus,     and       Yersinia        white. The specific activity of camel milk
enteroclitica were sporadically detected            lysozyme was found to be lower than that
in the same samples. Al-Saleh, et al.               of lysozyme from the human milk or
1997 stated that the Pseudomonas                    from egg white.
flourescens which was isolated from                     Camel milk has the ability to inhabit
camel raw milk (bulk milks) showed                  the growth of pathogenic micro-
maximum growth and proteinase activity              organisms because it contains number of
in Trypticase soya both (TSB) at 27oC               enzymes with ant-bacterial and anti-viral
after 32 and 24 h respectively. Optimum             properties these are: Lactoferrin which
temperature was 37˚C for growth, and                prevents microbial growth in the gut
27oC, for proteinase production, however            Lacto peroxides that suppresses gram-
proteinase was produced at all                      negative bacteria and most effective in
temperatures        studied       (7–37oC).         raw milk during the first 4 days,
Proteinase production in (TSB) was                  peptidoglycan recognition protein
enhanced by addition of skim milk or                (PGRP) that broad anti-microbial
casein, but not by alpha–casein. The                activity, stimulates the immune system,
presence of amino acids or peptides was             N-acetyl-glucosaminidase         (NAGase)
necessary for proteinase production.                antiviral activity, Lysozyme which
Growth and proteinase production were               inhabits the growth of bacteria, and has
enhanced by aeration occurred over a                effective influence on the storage camel
wide pH range. Growth was maximum at                milk, and immunoglobulins these
pH 6.7–6.9 and proteinase production at             possess several traits which give them
pH 6.9. Addition of glucose at increasing           tremendous advantage over conventional
concentrations up to 0.8%, enhanced                 antibodies (Werney 2003). El-Agamy et
growth, but had negligible effect on                al. (1992) extracted lysozyme, lactoferrin,

Emir. J. Food Agric. 2008. 20 (1): 76-83

lactoperoxidase, immunoglobulin A,                 perfringens, Listeria monocytogenes, and
from camel milk. The activity of these             Salmonella spp. All the microbiological
protective proteins was assayed against            analysis was carried according to FAO
Lactococcus lactis sub-sp., Cremoruse,             (1992).
Escherichia coli, Staphylococcus aureus,
Salmonella typhimurium and rotavirus.              Aerobic plate count
The antibacterial activity spectrum of                For this test plate count agar (Himedia
camel milk was similar to that of egg              laboratories PVT. Limited) was used,
white lysozyme and different from the              plates were incubated for 48 hrs at 35 oC.
lysozyme of bovine milk. Bovine and
camel milk lactoferrin, antibacterial               Enumeration of total coli forms
activity spectra were similar. Camel milk             Presumptive test was done using
lacto peroxidases were bacteriostatic              MacConkey broth, and tubes were
against the gram-negative cultures, the            incubated at 37oC, examined for gas
immunoglobulin had little effect against           production and growth after 24h. A
the bacteria, but high titers antibodies           confirmation test was done using BGB
against rotavirus were found in camel              broth for total coliform, and L-EMB agar
milk.                                              for E.coli and incubated at 35oC for 18-
   The main objectives of this study were          24h.Two typical colonies from each L-
to (1) investigate the microbial quality of        EMB plate were picked and transferred to
camel milk, (2) detect the pathogenic              plate count agar slants for morphological
bacteria, (3) enumerate the bacteria that          and biochemical tests.
may cause changes in camel milk and the
distribution of those bacteria.                    Enumeration of yeast and moulds
                                                       Dilution plating technique, with potato
Materials and Methods                              dextrose agar (Himedia laboratories PVT
                                                   Limited) was used, plates were incubated
    This study was conducted in Al-Ain             at 22-25ْ C for 5 days.
Food Laboratories, (Abu Dhabi Food
Central Authority) , UAE. Camel milk               Enumeration of Staphylococcus aureus
samples were collected from 118 lactating             Direct plate count method was used
camels, from two different private camel           with Baird-Parker medium (Oxoid)
herds, one herd from Central region
(Alrawi) and the other from the Southern           Detection of B. Cereus
region of (Al Ain) United Arab Emirates.               Bacillus cereus agar (Oxoid CM 617)
All camels were in mid lactation (2nd to           and Polymaxin B (50.000 units) was
5th month of lactation) 250 ml, sterilized         added to the Bacillus cereus selective
plastic containers were used for the               supplementary then 50 ml of sterile Egg
collection of samples.                             Yolk emulsion was added Incubated at
    The camels used for the milk                   30°C for 2 hr. gram stains were made and
collection were healthy and uninfected.            APl 50 CHB system was used for
The udder was cleaned and washed with a            identification. The confirmation test was
disinfectant solution (Safflon; 20%                done using Bacillus cereus agar and
concentration). The samples were                   incubated at 30°C for 18-24 hrs. Gram
analyzed for total aerobic plate count,            stained smears were made and
total coli form, total Staphylococcus              examined microscopically. Bacillus
aureus, and total yeast and mould. Also,           cereus will appear as large gram positive
samples were analyzed for the detection            bacilli in short to long chains spores are
of     Bacillus    cereus,   Clostridium           ellipsoidal and central to sub-terminal.
                                                   API strip was inoculated and incubated

Omer, R. H. and A. H. Eltinay
at 30°C. The result was read                         for growth, colony morphology, and any
according     to the manufactures                    change in the medium.
                                                     Purification of Bacterial Cultures
Detection of Clostridium perfringens                     Pure cultures of bacteria were
   Clostridium perfringens was detected              obtained by sub-culturing from a typical
according to the method of (ICMSF,                   and well-isolated colony on solid
1988). Using Cooked Meat Medium                      media (isolation media) till pure
(Oxoid.), Perfringens Agar (TSC&SFP)                 bacterial growth was obtained.
and Neomycm, 1% solution. Incubated                  Identification of bacterial cultures
for 2 4 hr at 35-37oC.                               For the identification of unknown
                                                     bacteria the steps were followed:
Detection of Listeria monocytogenes                  1) Making of smears, stained with gram-
   Listeria monocytogenes was detected               staining technique according to Green
according to the method of FAO (1992).               berge et al. (1992). 2) Motility, motility
Using 1) Listeria enrichment broth base              of bacteria was studied by Hanging Drop
(Oxoid); 2) Oxford agar; plates were                 Technique according to Cowan and Steel
incubated at 35 ْC for 24-8hr.                       (1990).

Detection of Salmonella                              Biochemical identification
   Salmonella was detected according to                  API 20E: was used for identification
the method of FAO (1992). Pre                        of Enterobacteriaceae. - API 50 CHB
enrichment medium (Buffer peptone                    for Bacillus. - ID 32 C for yeast. - ID 32
water)-Enrichment      broth    (Rapport-            Staph for Staph spp. - ID 32 GN for gram-
vassiliadis)     (RV)-Xylose       Lysine            negative rods.
Descoxychalate (XLD) agar (Himedia)-
Triple sugar iron agar (TSI) were used,              Results and Discussion
incubated at 35oC for 24hr. API 20E Test
System was used for diagnostic                          The aerobic plate count is an indication
                                                     of the sanitary conditions under which the
Isolation of Bacterial Cultures                      food was produced (Andrews, 1992).
   The main groups of microorganisms                 Total Aerobic plate count (APC) values
and their components comprising the                  may range from >100ml1 to 1×106 / ml of
microflora of milk were detected by                  milk, consequently high initial APC
isolations, purification, and identification.        values in milk e.g.>100,000 ml 1 are
The samples were cultured on different               evidence of serious faults in production
media e.g. Gram positive bacteria,                   hygiene, where as the production of milk
cultured on Blood agar media, gram-                  having APC values <20,000/ml reflects
negative       bacteria     cultured       on        good hygiene practices (International
MacConkey agar, Staphylococcus aureus                Dairy Federation, 1974).
on baird parker agar, Bacillus cereus on                 Table 1 shows the means the standard
mannitol-egg-yolk-polymxin              agar.        deviations and the ranges of bacterial
Escherichia coli on Levine's eosin-                  counts of the camel's raw milk. The
methylene blue agar (L-EMB). Yeast                   aerobic plate count varied from 5 x 10 2
cultured on Potato dextrose agar. The                to 7.4 xl05 cfu/ ml with an average of
culture was inoculated by streaking.                 1.8×105 ± 2.3×104 cfu/ml. Out of 50
Inoculated media were incubated                      samples tested, 22 samples were found to
aerobically at different temperatures (25,           contain bacterial counts excess of 103
30, 35oC) for 24-48 hrs. The solid media             cfu/ml. This was lower than that
plates were examined, microscopically                reported by Al-Mohizea (1986) for the

    Emir. J. Food Agric. 2008. 20 (1): 76-83

    total aerobic count of camel’s milk in                 1.0xl02 cfu/ml, with a mean value of
    Riyadh markets (2.2 x 105 cfu/ml), this                4.1x101 cfu/ml ( Table 1).
    may be due to that our samples were                        Table (2) shows the distribution of
    collected from individual farms, under                 bacterial counts of camel’s raw milk.
    highly controlled conditions. The Al-                  Fifty samples were tested for total
    Mohizea samples were collected from                    aerobic counts, 2 samples < 104
    markets, which might be from numerous                  cfu/ml, 26 samples >104       cfu/ml, 22
    farms. Table 1 also indicated the mean                 samples >10 cfu/ml, Nil samples
    values, the range, and the standard                    approached 106. Fifty two samples were
    deviation of total coliform in camel                   tested for total Coliforms, 10 samples
    milk. It varies between 4 cfu/ml to 2.1x               were <10 cfu/ml 32 samples were
    102cfu/ml, with a mean value of 6.8                    >101cfu/ml. And 10 samples were >102
    xl01 ±6.6x 101 .Out of 52 milk samples                 cfu/ml. Twenty five samples showed
    tested for coliform, 10 samples exceed                 positive for Staphylococcus aureus, 3
    102 cfu/ml. This was considered low in                 samples were <102 cfu/ml, 14 samples
    comparison to that found by Al-                        <103 cfu/ml, 8 samples <104 cfu/ml.
    Mohizea (1986) for Saudi Arabia camel                      Table 3 shows results of the total
    milk (5.1x105 cfu/ml) and this generally               aerobic count of dromedary camel milk
    provides an index of the sanitation used               with corresponding values for cow milk
    during collection. The presence of S                   as reported by Mamoun (1981) for
    aureus indicated contamination from the                Sudanese cow milk. The value range
    skin, mouth, or the nose of the food                   from 5.4 x 105 to 6.7 x 105 cfu/ml. From
    handler (FAO, 1992). The S. aureus                     the data on table 3 we can observe a
    count ranged from 2.1xl02 to 7.2xl03                   wide variation between species. This
    cfu/ml with a mean value of 1.2x103 cfu                wide variation may be ascribed to the
    /ml (Table 1). All the samples tested                  failure in maintaining consistent
    were found negative for molds.                         sanitary conditions, and for storage
    Concerning the yeast 7 samples out of                  temperature, (Cousin and Bramley,
    the (68) samples tested were found                     1981).
    positive, and ranging from 1.3x102 to

                         Table 1. Mean counts (cfu/ml) of Aerobic Plate Count.

                   Microorganisms              Range                Mean         SD*
                  Total Aerobic          5 × 102 – 7.4 × 105      1.8 × 105     2.3×104
                  Total coliform         4cfu/ml _ 2×102           6.8×101      6.6×101
                  Total Staph.           2.1×102 – 7.2×103         1.2×103      1.5×102
                  Total yeast            1.3×101 – 1.0×102         4.1×101      3.1×101
                 * SD =Standard deviations

                       Table 2. Distribution of bacterial count of camel's raw milk.

                  Aerobic plate count (cfu/ml)      Total coliform ( cfu/ml)        Total aureus (cfu/ml)
                  <103 >104 >105 >106              <10      <102     <0.3x104       <102    <103     <104
No. of samples    2      26        22   Nil         10            32       10          3    14       8

%                  4      52       44   0           19.2          61     19.2       12     56       32

Omer, R. H. and A. H. Eltinay

       Table 3. Total bacterial count of camel milk compared with cow milk (Range and
                                          mean values).

                    Present study                 Camel*                     Cow a
    Ranges         5.×102 - 7.4×105           1.7×102 - 5 ×106         5.4 ×105 - 6.7×105
     Means            1.8 × 105                  2.2 × 105                      -
    * Adapted from Al-mohizea (1986)
    a Adapted from Mamoun (1981)

Pathogenic Bacteria in raw camel                     Elnazier (2000) for raw bovine milk at
milk                                                 Soba in Khartoum States, which ranged
    Raw camel milk may contain                       between Nil to > 2000 cfu/ml. These
microorganisms pathogenic for man,                   negative results against the occurrence of
and their source may lie either within               most pathogenic bacteria, might be due
or out side the udder. Pathogenic                    to the activity of protective proteins
bacteria may present in raw milk as a                (Lysozyme, lactoferrin, lactoperoxldase,
direct consequence of udder disease.                 immunoglobulm G and A) of camel's
Among the organisms commonly                         milk, as reported by Barbour et al. (1984),
producing            mastitis          are           and El-Agamy, (1992), who found that
Staphylococcus aureus, and Escherichia               camel milk lysozyme (LZ) was effective
coli, and all are pathogenic Sinell                  against Salmonella, but ineffective
(1973).Contamination of raw milk by                  toward Staph aureus, and that camel milk
pathogenic bacteria from source external             Lactoperoxidase was bacteriostatic
to the udder may be caused by                        against the gram-positive strains,
salmonellae strains, which produce                   and was bactericidal against gram-
many out breaks of enteritis Robinson                negative cultures.
et al. 1979.
    Table 4 shows some pathogenic                    The total aerobic bacterial content of
bacteria isolated from camel raw milk.               raw camel milk
Sixty eight samples were tested, for the                Many types of bacteria was isolated
detection of Staphylococcus aureus,                  and identified, with varying isolation
Bacillus     cereus,      and     Listeria           levels from 46 samples. The bacterium
monocytogens, and Salmonella spp.,                   that was isolated was:
Clostridium perfringens. All the
                                                     The gram-positive cocci
samples tested were negative for
                                                        Staphylococci: were isolated from 15
Listeria monocytogens, Salmonella
                                                     milk samples. The average rate of
spp., and Clostridium         perfringens.
                                                     isolation from all samples was 31.91%
Twenty one percent of the samples were
                                                     (Table5). The named species are
found positive for Bacillus cereus. All the
                                                     Staphylococcus aureus         (Ref. 8),
samples tested were found positive for
                                                     Staphylococcus capre (Ref. 7),
Staph. Spp. and 37% of these samples
                                                     Staphylococcus     hyicus (Ref. 22), and
were found positive for Staphylococcus,
                                                     Staphylococcus xylosue (ref 6) (the most
aureus. Our findings were comparable to
                                                     dominant one)
that found by Al-Mohizea (1986), the
only difference is that he found S.
                                                     Other gram-positive cocci
aureus in all samples he tested. The
                                                        e.g. Streptococcus, Micrococcus,
percent in this study is low compared to
                                                     Aerococcus were isolated from 20 milk
the percentage of S. aureus found in
                                                     samples. The average rate of isolation
bovine milk (42%) as reported by
                                                     from all samples was 42.55% (Table 5).

Emir. J. Food Agric. 2008. 20 (1): 76-83

The named species          is   Aerococcus             Aeromonus salm salmomcida(Ref.
viridians (Ref. 43).                                   MA10),           Escherichia        coli,
                                                       Enterobacter cloacae, and Eenterobacter
The gram-positive rods                                 aminigenus. Ahmed (1995) isolated the
   Bacillus species: were isolated from                same types of bacteria from cow milk
11 milk samples. The average of isolation              and he found that the average rate of
from all samples was 23.4%.                            isolation was 51.1% Staphylococcus,
                                                       29.6%         Streptococcus,      6.6%
The gram-negative cocci were isolated                  Micrococcus, 13.16% gram-positive
from 5 samples. The average rate of                    rods, and 2.27% gram-negative rods.
isolation from all samples was 10.6%.                     Yeast was isolated from 7 milk
                                                       samples. The rate of isolation from all
The gram-negative rods were isolated                   samples was 14.9%. The named species
from 14 milk samples. The average rate                 are Candida ciferri and Candida
of isolation from all samples was                      guilliermondii (Ref. 9).
29.8%. The named species are

      Table 4. Frequency Occurrence of some pathogenic bacteria in raw camel milk.

     Pathogenic bacteria           No. of sample tested     No. of positive       %
     Staph. aureus                           68                   25             36.8
     Bacillus cereus                         68                   14             20.6
     Listeria monocytogen                    68                    -               0
     Salmonella spp.                         68                    -               0
     Clostridium perfringens                 68                    _               0

                   Table 5. Types of bacteria isolated from raw camel milk.

     No. of samples              Organisms                   + ve samples         %
            47                  Gram+ ve cocci                    20             42.55
             47                 Gram + ve rods                    11             23.40
             47                 Gram - ve cocci                    5             10.64
             47                  Gram-ve rods                     14             29.79
             47                   Staph. Spp.                     15             31.91
             47                     Yeast                          7              14.89

References                                                Veterinary Public Health University
                                                          of Khartoum.
Ahmed, KH. H. 1995. The Keeping
  Quality of Raw, Pasteurized and                      Al-Mohizea, I. S. 1986 Microbial
  Sterilized Milk At Room, Refrigerator                  Quality of Camel’s Raw Milk in
  And Deep Freeze Temperatures.                          Riyadh Markets. Egyptian. J. Dairy
  Higher Degree Thesis, Department                       Sci. 173–180.
  of     Preventive    Medicine    and

Omer, R. H. and A. H. Eltinay
AL-Saleh, A. A. and A. Sl Zahran. 1997.
  Protease Production by seudomonus                 Farah, Z. 1993. A review article.
  fluoresces. Isolated from Raw Camel                  Composition and characteristics of
  Milk. Australian Journal of Dairy                    camel milk. J.   Dairy Research.
  Technology. 52(1):5 – 7.                             60:603 – 626.

Barbour, E. K., N. H. Nabbut, W. M.                 Green berg, A. E., L. S. Clesceri and A.
   Frechs. and H. M. AL-Nakhli. 1984.                  D. Eaton. 1992. Standard Methods
   Inhibition of Pathogenic Bacteria by                for Examination of Water & Waste
   Camels Milk Relation to Whey                        Water 18th edn.Prepared & Published
   Lysozyme and Stage of Lactation.J of                by APHA and American Water
   Food Production. 47:838-840.                        Works        Association        Water
                                                       Environment Federation.
Cowan, S. T. and Steel. 1990.
  Microscopic Examination of Mi                     International      Commission      on
  croorganisms     (Motility).      In:                 Microbiological Specifications for
  Microbiological Methods. Collins. C.                  Foods             (ICMSF). 1988.
  H. (Ed). pp.106.                                      Microorganisms in Food.

Cousins, C. M. and A. J. Bramley. 1981              International Dairy Federation. 1974.
  The Microbiology of Raw Milk. In                      Bacteriological Quality of Cooled
  Dairy Microbiology vol. 1. Robinson,                  bulk         Milk. Doc. No, 83, IDF,
  R.K(Ed)) pp. 119–163. APPL. SCI.                      Brussels.
  pub. London.
                                                    Mamoun, I. 1981 Aerobic Bacteria of
Duhaiman, A. S. 1988. Purification of                 Bovine Milk in Sudan. Higher Degree
  camel’s milk lysozyme and its lytic                 Thesis University of Khartoum.
  effect on E. coli and Micrococcus                   Sudan.
  lysodeikticus.   Comp.    Biochem.
  Physiol. 91b:793–796.                             Robinson, D. A., W. J. Edgar, G. L.
                                                      Gibson, A. A. Matcheit and A. A.
    El-Agamy, E. I., R. Ruppanner, A.                 Robertson. 1979. Campylobacter
      Ismail, C. P. Champagne and R.                  enteritis associated with consumption
      Assf. 1992.         Antibacterial and           of unpasteurized milk L. (1979). Brit.
      Antiviral Activity of Camel Protective          Medical J.1:1171.
      Proteins. J.        Dairy Research.
      (59):169–175.                                 Sinell, H. J. 1973 Food Infections, from
                                                       Animals. In: The Microbiological
Elnazier, M. E. 2000. The Enumeration                  Safety of Foods. Hobbs, B. C. and J.
   and Detection of Staphylococcus                     H. B. Christian (Eds). Academic
   aureus and Other Staphylococcal                     Press, London and New York.
   Sppl. In Raw Bovine Milk in Soba
   Country of Khartoum State. Higher                Wernery, U. 2003. New Observations on
   Degree    Thesis.   University  of                Camels and their Milk, pp.41-42. Dar
   Khartoum. Sudan.                                  Al Fajr pub. Abu Dhabi, United Arab
FAO. 1992 Manual of Food Quality
  Control 4.Rev. 1.Microbiological
  Analysis        Food & Agriculture
  Organization Rome. Italy.


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