Staphylococcal Gastroenteritis 547
and 22% of 272 coagulase negatives were enterotoxin positive.
111 ). SEC was the most frequently
found enterotoxin among the goat isolates. Seven species of the goat isolates produced more than
one enterotoxin (S. caprae, S. epidermidis, S. haemolyticus, S. saprophyticus, S. sciuri, S. warneri,
and S. xylosus) and two species produced only one—SEC by S. chromogens and SEE by S. lentus.
111
From cooked ready-to-eat crabmeat, the following species were identified among 100 staphylococcal
suspect isolates: S. lentus—31; S. hominis—21; S. epidermidis—10; S. kloosi—8; S. capitis—5; and 3
each of S. aureus,S. saprophyticus, and S. sciuri.
32 Fewer than three of five other species were found.
From Spanish dry-cured hams, an SEC-producing S. epidermidis was isolated.
69
Among other foodborne staphylococcal species are S. condimenti,S. piscifermentans, and S. fleurettii, all of which are coagulase, TNase, and enterotoxin negative. S. condimenti was isolated from
soy sauce mash,
87 S. piscifermentans from fermented fish in Thailand,
105 and S. fleurettii from
goat’s milk cheeses.
114 The former S. caseolyticus has been transferred to the genus Macrococcus as
M. caseolyticus
64
HABITAT AND DISTRIBUTION
The staphylococcal species are host-adapted with about one-half of the known species inhabiting
humans solely (e.g., S. cohnii subsp. cohnii) or humans and other animals (e.g., S. aureus). The largest
numbers tend to be found near openings to the body surface such as the anterior nares, axillae, and
the inguinal and perineal areas where in moist habitats, numbers per square centimeter may reach
10
3 –10
6 , and in dry habitats, 10–10
3 .
63 The two most important sources to foods are nasal carriers
and individuals whose hands and arms are inflicted with boils and carbuncles, who are permitted to
handle foods.
Most domesticated animals harbor S. aureus. Staphylococcal mastitis is not unknown among dairy
herds, and if milk from infected cows is consumed or used for cheese making, the chances of contracting
food intoxication are excellent. There is little doubt that many strains of this organism that cause
bovine mastitis are of human origin. However, some are designated as “animal strains.” In one study,
staphylococcal strains isolated from parts of raw pork products were essentially all of the animal strain
type. However, during the manufacture of pickled pork products, these animal strains were gradually
replaced by human strains during the production process, to a point where none of the original animal
strains could be detected in finished products.
95
With regard to some of the non-S. aureus species, S. cohnii is found on the skin of humans and
occasionally in urinary tract and wound infections. Human skin is the habitat of both S. epidermidis
and S. haemolyticus, and the latter is associated with human infections. S. hyicus is found on the skin
of pigs, where it sometimes causes lesions, and it has been found in milk and on poultry. The skin
of lower primates and other mammals is the habitat of S. xylosus, and the skin of humans and other
primates is the habitat of S. simulans. S. schleiferi subsp. schleiferi was found in clinical specimens
from human patients with decreased resistance to infection,
37 and subsp. coagulans was isolated
from ear infections in dogs. S. aureus subsp. anaerobius causes disease in sheep, and S. delphini was
recovered from dolphins.
113 S. sciuri is found on the skin of rodents and S. lentus and S. caprae are
associated with goats, especially goat milk.
Although many of the coagulase-negative species noted adapt primarily to nonhuman hosts, their
entry into human foods is not precluded. Once in susceptible foods, their growth may be expected to
lead to the production of enterotoxins. All of these species grow in the presence of 10% NaCl.
Since S. aureus has been studied most as a cause of staphylococcal foodborne gastroenteritis, most
of the information that follows is about this species.
and 22% of 272 coagulase negatives were enterotoxin positive.
111 ). SEC was the most frequently
found enterotoxin among the goat isolates. Seven species of the goat isolates produced more than
one enterotoxin (S. caprae, S. epidermidis, S. haemolyticus, S. saprophyticus, S. sciuri, S. warneri,
and S. xylosus) and two species produced only one—SEC by S. chromogens and SEE by S. lentus.
111
From cooked ready-to-eat crabmeat, the following species were identified among 100 staphylococcal
suspect isolates: S. lentus—31; S. hominis—21; S. epidermidis—10; S. kloosi—8; S. capitis—5; and 3
each of S. aureus,S. saprophyticus, and S. sciuri.
32 Fewer than three of five other species were found.
From Spanish dry-cured hams, an SEC-producing S. epidermidis was isolated.
69
Among other foodborne staphylococcal species are S. condimenti,S. piscifermentans, and S. fleurettii, all of which are coagulase, TNase, and enterotoxin negative. S. condimenti was isolated from
soy sauce mash,
87 S. piscifermentans from fermented fish in Thailand,
105 and S. fleurettii from
goat’s milk cheeses.
114 The former S. caseolyticus has been transferred to the genus Macrococcus as
M. caseolyticus
64
HABITAT AND DISTRIBUTION
The staphylococcal species are host-adapted with about one-half of the known species inhabiting
humans solely (e.g., S. cohnii subsp. cohnii) or humans and other animals (e.g., S. aureus). The largest
numbers tend to be found near openings to the body surface such as the anterior nares, axillae, and
the inguinal and perineal areas where in moist habitats, numbers per square centimeter may reach
10
3 –10
6 , and in dry habitats, 10–10
3 .
63 The two most important sources to foods are nasal carriers
and individuals whose hands and arms are inflicted with boils and carbuncles, who are permitted to
handle foods.
Most domesticated animals harbor S. aureus. Staphylococcal mastitis is not unknown among dairy
herds, and if milk from infected cows is consumed or used for cheese making, the chances of contracting
food intoxication are excellent. There is little doubt that many strains of this organism that cause
bovine mastitis are of human origin. However, some are designated as “animal strains.” In one study,
staphylococcal strains isolated from parts of raw pork products were essentially all of the animal strain
type. However, during the manufacture of pickled pork products, these animal strains were gradually
replaced by human strains during the production process, to a point where none of the original animal
strains could be detected in finished products.
95
With regard to some of the non-S. aureus species, S. cohnii is found on the skin of humans and
occasionally in urinary tract and wound infections. Human skin is the habitat of both S. epidermidis
and S. haemolyticus, and the latter is associated with human infections. S. hyicus is found on the skin
of pigs, where it sometimes causes lesions, and it has been found in milk and on poultry. The skin
of lower primates and other mammals is the habitat of S. xylosus, and the skin of humans and other
primates is the habitat of S. simulans. S. schleiferi subsp. schleiferi was found in clinical specimens
from human patients with decreased resistance to infection,
37 and subsp. coagulans was isolated
from ear infections in dogs. S. aureus subsp. anaerobius causes disease in sheep, and S. delphini was
recovered from dolphins.
113 S. sciuri is found on the skin of rodents and S. lentus and S. caprae are
associated with goats, especially goat milk.
Although many of the coagulase-negative species noted adapt primarily to nonhuman hosts, their
entry into human foods is not precluded. Once in susceptible foods, their growth may be expected to
lead to the production of enterotoxins. All of these species grow in the presence of 10% NaCl.
Since S. aureus has been studied most as a cause of staphylococcal foodborne gastroenteritis, most
of the information that follows is about this species.