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Ljevaković-Musladin I, Kozačinski L, Krilanović M, Vodnica Martucci M, Lakić M, Grispoldi L, Cenci-Goga BT. Enterotoxigenic and Antimicrobic Susceptibility Profile of Staphylococcus aureus Isolates from Fresh Cheese in Croatia. Microorganisms 2023; 11:2993. [PMID: 38138137 PMCID: PMC10745915 DOI: 10.3390/microorganisms11122993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/09/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Certain Staphylococcus aureus strains harbour staphylococcal enterotoxin genes and hence can produce enterotoxin during their growth in food. Therefore, food can be a source of staphylococcal food poisoning, one of the most common food-borne diseases worldwide. Epidemiological data show that S. aureus is often present in raw milk cheeses, and consequently, cheeses are often the source of staphylococcal food poisoning outbreaks. The aim of this study was to determine the phenotypic characteristics of S. aureus isolates from fresh cheese, including antibiotic susceptibility; the presence of classical sea-see enterotoxin genes through molecular methods; and the isolate's ability to produce SEA-SEE enterotoxins in vitro through reversed passive latex agglutination. A total of 180 coagulase-positive staphylococci were isolated from 18 out of 30 cheese samples, and 175 were confirmed as S. aureus through latex agglutination and API STAPH tests. All isolates possessed phenotypic characteristics typical for S. aureus, with certain variations in the egg yolk reaction (18.3% of the isolates showed a weak reaction and 28% no reaction at all) and haemolysis pattern (36.6% of the isolates produced double-haemolysis and 4.6% were non-haemolytic). Antibiotic resistance was observed in 1.1% of the isolates and to mupirocin only. Real-time PCR detected the sec gene in 34 (19.4%) isolates, but most isolates (80.6%) were not enterotoxigenic. For all 34 (19.4%) strains that carried the sec gene, the RPLA method detected the production of the SEC enterotoxin in vitro. For those enterotoxigenic strains, the possibility of enterotoxin production in fresh cheese could not be ruled out.
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Affiliation(s)
- Ivana Ljevaković-Musladin
- Environmental Health Department, Public Health Institute of Dubrovnik-Neretva County, Dr. A. Šercera 4A, HR-20000 Dubrovnik, Croatia;
| | - Lidija Kozačinski
- Department of Hygiene, Technology and Food Safety, Faculty of Veterinary Medicine University of Zagreb, Heinzelova 55, HR-10000 Zagreb, Croatia;
| | - Marija Krilanović
- Microbiology Department, Public Health Institute of Dubrovnik-Neretva County, Dr. A. Šercera 2C, HR-20000 Dubrovnik, Croatia; (M.K.); (M.V.M.)
| | - Marina Vodnica Martucci
- Microbiology Department, Public Health Institute of Dubrovnik-Neretva County, Dr. A. Šercera 2C, HR-20000 Dubrovnik, Croatia; (M.K.); (M.V.M.)
| | - Mato Lakić
- Environmental Health Department, Public Health Institute of Dubrovnik-Neretva County, Dr. A. Šercera 4A, HR-20000 Dubrovnik, Croatia;
| | - Luca Grispoldi
- Laboratorio di Ispezione Degli Alimenti di Origine Animale, Department of Veterinary Medicine, University of Perugia, 06126 Perugia, Italy; (L.G.); (B.T.C.-G.)
| | - Beniamino T. Cenci-Goga
- Laboratorio di Ispezione Degli Alimenti di Origine Animale, Department of Veterinary Medicine, University of Perugia, 06126 Perugia, Italy; (L.G.); (B.T.C.-G.)
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Etter D, Jenni C, Tasara T, Johler S. Mild Lactic Acid Stress Causes Strain-Dependent Reduction in SEC Protein Levels. Microorganisms 2021; 9:1014. [PMID: 34066749 PMCID: PMC8151770 DOI: 10.3390/microorganisms9051014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/30/2021] [Accepted: 05/05/2021] [Indexed: 12/12/2022] Open
Abstract
Staphylococcal enterotoxin C (SEC) is a major cause of staphylococcal food poisoning in humans and plays a role in bovine mastitis. Staphylococcus aureus (S. aureus) benefits from a competitive growth advantage under stress conditions encountered in foods such as a low pH. Therefore, understanding the role of stressors such as lactic acid on SEC production is of pivotal relevance to food safety. However, stress-dependent cues and their effects on enterotoxin expression are still poorly understood. In this study, we used human and animal strains harboring different SEC variants in order to evaluate the influence of mild lactic acid stress (pH 6.0) on SEC expression both on transcriptional and translational level. Although only a modest decrease in sec mRNA levels was observed under lactic acid stress, protein levels showed a significant decrease in SEC levels for some strains. These findings indicate that post-transcriptional modifications can act in SEC expression under lactic acid stress.
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Affiliation(s)
- Danai Etter
- Institute for Food Safety and Hygiene, University of Zurich, 8057 Zurich, Switzerland; (D.E.); (T.T.)
- Laboratory of Food Microbiology, Institute for Food, Nutrition and Health (IFNH), ETH Zurich, 8092 Zurich, Switzerland;
| | - Céline Jenni
- Laboratory of Food Microbiology, Institute for Food, Nutrition and Health (IFNH), ETH Zurich, 8092 Zurich, Switzerland;
| | - Taurai Tasara
- Institute for Food Safety and Hygiene, University of Zurich, 8057 Zurich, Switzerland; (D.E.); (T.T.)
| | - Sophia Johler
- Institute for Food Safety and Hygiene, University of Zurich, 8057 Zurich, Switzerland; (D.E.); (T.T.)
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3
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Lee SI, Kim SD, Park JH, Yang SJ. Species Distribution, Antimicrobial Resistance, and Enterotoxigenicity of Non- aureus Staphylococci in Retail Chicken Meat. Antibiotics (Basel) 2020; 9:antibiotics9110809. [PMID: 33203011 PMCID: PMC7697432 DOI: 10.3390/antibiotics9110809] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/07/2020] [Accepted: 11/12/2020] [Indexed: 12/19/2022] Open
Abstract
Non-aureus staphylococci (NAS), including coagulase-negative staphylococci, have emerged as important causes of opportunistic infections in humans and animals and a potential cause of staphylococcal food poisoning. In this study, we investigated (i) the staphylococcal species profiles of NAS in in retail chicken meat, (ii) the phenotypic and genotypic factors associated with antimicrobial resistance in the NAS isolates, and (iii) the prevalence of classical and newer staphylococcal enterotoxin (SE) genes. A total of 58 NAS of nine different species were isolated from retail raw chicken meat samples. The occurrence of multidrug resistance in the NAS, particularly S. agnetis and S. chromogenes, with high resistance rates against tetracycline or fluoroquinolones were confirmed. The tetracycline resistance was associated with the presence of tet(L) in S. chromogenes and S. hyicus or tet(K) in S. saprophyticus. The occurrence of fluoroquinolone resistance in S. agnetis and S. chromogenes was usually associated with mutations in the quinolone resistance determining regions (QRDR) of gyrA and parC. In addition, the frequent presence of SE genes, especially seh, sej, and sep, was detected in S. agnetis and S. chromogenes. Our findings suggest that NAS in raw chicken meat can have potential roles as reservoirs for antimicrobial resistance and enterotoxin genes.
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Etter D, Schelin J, Schuppler M, Johler S. Staphylococcal Enterotoxin C-An Update on SEC Variants, Their Structure and Properties, and Their Role in Foodborne Intoxications. Toxins (Basel) 2020; 12:E584. [PMID: 32927913 PMCID: PMC7551944 DOI: 10.3390/toxins12090584] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 09/07/2020] [Accepted: 09/08/2020] [Indexed: 12/20/2022] Open
Abstract
Staphylococcal enterotoxins are the most common cause of foodborne intoxications (staphylococcal food poisoning) and cause a wide range of diseases. With at least six variants staphylococcal enterotoxin C (SEC) stands out as particularly diverse amongst the 25 known staphylococcal enterotoxins. Some variants present unique and even host-specific features. Here, we review the role of SEC in human and animal health with a particular focus on its role as a causative agent for foodborne intoxications. We highlight structural features unique to SEC and its variants, particularly, the emetic and superantigen activity, as well as the roles of SEC in mastitis and in dairy products. Information about the genetic organization as well as regulatory mechanisms including the accessory gene regulator and food-related stressors are provided.
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Affiliation(s)
- Danai Etter
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zürich, 8057 Zürich, Switzerland;
- Laboratory of Food Microbiology, Institute of Food, Nutrition and Health, ETH Zürich, 8092 Zürich, Switzerland;
| | - Jenny Schelin
- Division of Applied Microbiology, Department of Chemistry, Lund University, 22100 Lund, Sweden;
| | - Markus Schuppler
- Laboratory of Food Microbiology, Institute of Food, Nutrition and Health, ETH Zürich, 8092 Zürich, Switzerland;
| | - Sophia Johler
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zürich, 8057 Zürich, Switzerland;
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5
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Valihrach L, Alibayov B, Zdenkova K, Demnerova K. Expression and production of staphylococcal enterotoxin C is substantially reduced in milk. Food Microbiol 2014; 44:54-9. [PMID: 25084645 DOI: 10.1016/j.fm.2014.05.020] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Revised: 05/25/2014] [Accepted: 05/26/2014] [Indexed: 11/29/2022]
Abstract
Staphylococcal food poisoning is a global problem. The gene encoding enterotoxin C (sec) has been reported several times as the most frequent enterotoxin gene identified in food poisoning cases caused by contaminated milk. In this study, the expression of sec was examined during the growth of Staphylococcus aureus in milk compared to routinely used laboratory media. Additionally, expression of several regulatory genes (sarA, saeS, codY, srrA, rot, hld, agrA, sigB) and other five enterotoxin genes (sea, seg, seh, sek, sel) were observed. It has been well established for that S. aureus is able to grow in milk and we found significantly reduced expression of sec in milk compared to the laboratory medium (P < 0.05). Here, we report the first study providing a comprehensive view on the expression of enterotoxin genes and its regulation in milk. The milk environment dramatically changed the expression profiles of several enterotoxin genes although staphylococcal growth was not affected at all. The mechanism of the reduction may be explained by downregulation of the agr system, although other factors are expected to be involved. The constituent of milk causing the inhibitory effect remains unidentified.
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Affiliation(s)
- Lukas Valihrach
- Institute of Chemical Technology Prague, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Technicka 5, Prague, 166 28, Czech Republic
| | - Babek Alibayov
- Institute of Chemical Technology Prague, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Technicka 5, Prague, 166 28, Czech Republic.
| | - Kamila Zdenkova
- Institute of Chemical Technology Prague, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Technicka 5, Prague, 166 28, Czech Republic
| | - Katerina Demnerova
- Institute of Chemical Technology Prague, Faculty of Food and Biochemical Technology, Department of Biochemistry and Microbiology, Technicka 5, Prague, 166 28, Czech Republic
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Linage B, Rodríguez-Calleja J, Otero A, García-López M, Santos J. Characterization of coagulase-positive staphylococci isolated from tank and silo ewe milk. J Dairy Sci 2012; 95:1639-44. [DOI: 10.3168/jds.2011-4734] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 11/30/2011] [Indexed: 11/19/2022]
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D'amico DJ, Donnelly CW. Characterization of Staphylococcus aureus strains isolated from raw milk utilized in small-scale artisan cheese production. J Food Prot 2011; 74:1353-8. [PMID: 21819666 DOI: 10.4315/0362-028x.jfp-10-533] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Staphylococcus aureus is an important agent of bacterial mastitis in milking animals and of foodborne intoxication in humans. The purpose of this study was to examine the genetic and phenotypic diversity, enterotoxigenicity, and antimicrobial resistance of S. aureus strains isolated from raw milk used for the production of artisan cheese in Vermont. Cross-tabulations revealed that the 16 ribotypes identified among the 90 milk isolates examined were typically associated with a specific animal species and that more than half of these ribotypes were unique to individual farms. In general, specific EcoRI ribotypes were commonly associated with specific phenotypical characteristics, including staphylococcal enterotoxin production or the lack thereof. Limited antimicrobial resistance was observed among the isolates, with resistance to ampicillin (12.51%) or penicillin (17.04%) most common. Two isolates of the same ribotype obtained from the same farm were resistant to oxacillin with 2% NaCl. More than half (52.22%) of isolates produced toxin, and 31 of the 32 isolates solely produced staphylococcal enterotoxin type C. Although these data demonstrate that S. aureus strains found in raw milk intended for artisan cheese manufacture are capable of enterotoxin production, staphylococcal enterotoxin C is not typically linked to foodborne illness. Because S. aureus is a common contaminant of cheese, an understanding of the ecology of this pathogen and of the antimicrobial susceptibility and toxigenicity of various strains will ultimately contribute to the development of control practices needed to enhance the safety of artisan and farmstead cheese production.
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Affiliation(s)
- Dennis J D'amico
- Department of Nutrition and Food Sciences, University of Vermont, Bington, Vermont 05405, USA.
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9
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Kalinina NA, Samokhvalova LV, Ulitin AB, Vertiev IV, Nesmeianov VA. [Molecular cloning, expression, and characterization of human mini-antibodies against enterotoxin C1 of Staphylococcus aureus]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2009; 35:192-201. [PMID: 19537170 DOI: 10.1134/s1068162009020058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We describe here the cloning, expression, and production of specific single-chain antibodies (scFv) against the recombinant enterotoxin C1 of Staphylococcus aureus. High-affinity scFv were selected from the phage library of human mini antibodies; afterwards, the cells of E. coli trxA gor double mutant were infected with a product obtained by fusion of DNA encoding of these mini antibodies with the trxA gene to induce soluble scFv synthesis in cell cytoplasm. The scFv obtained displayed high enterotoxin C1 affinity. Analysis for cross reactivity showed that mini-antibodies interacted also with SEA- SEB-, SED-, SEE-, SEG-, and SEI-type enterotoxins, but they failed to interact with ricin, diphtheritic, and cholera toxins, or with both lethal and protective factors of the anthrax toxin. This property may be helpful in screening for staphylococcus enterotoxins.
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Abstract
SummaryForty-five strains of staphylococci and 6 strains of micrococci isolated from pasteurized ewes' milk cheeses (Manchego and Burgos varieties) were identified to species level. Three strains of staphylococci were identified asStaphylococcus aureus. Amongst the 42 coagulase-negative staphylococci, 8 were novobiocin-sensitive and 34 novobiocin-resistant. The novobiocin-sensitive species found wereStaph. auricularis(5 strains),Staph. caseolyticus(2 strains) andStaph. epidermidis(1 strain). Novobiocin-resistant strains were identified asStaph. gallinarum(5 strains),Staph. xylosus(4),Staph. saprophyticus(9),Staph. cohnii(6),Staph. sciuri(1) andStaph. lentus(3). The other 6 isolates could not be identified. Only 3 strains of micrococci were identified (Micrococcus kristinae, M. variansandM. sedentarius). The possible origin of the isolates is discussed.
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11
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Orden JA, Goyache J, Hernández J, Doménech A, Suárez G, Gómez-Lucía E. Detection of enterotoxins and TSST-1 secreted by Staphylococcus aureus isolated from ruminant mastitis. Comparison of ELISA and immunoblot. THE JOURNAL OF APPLIED BACTERIOLOGY 1992; 72:486-9. [PMID: 1644704 DOI: 10.1111/j.1365-2672.1992.tb01863.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The production of staphylococcal enterotoxins (SE) and toxic shock syndrome toxin-1 (TSST-1) was studied in 81 strains of Staphylococcus aureus isolated from cases of mastitis in cattle, goats and sheep. SE and TSST-1 were detected by two techniques: ELISA double antibody sandwich, and an immunoblot technique combined with a semiautomated electrophoresis system. More Staph. aureus strains isolated from sheep produced enterotoxins than those from goats and cattle. SEC was the predominant type in all isolates from these animal species. The highest proportion of strains producing TSST-1 were obtained from sheep, twice as many as those from goats or cows. The two techniques gave similar results, as all the strains positive by immunoblot were also positive by ELISA, and only three were positive by ELISA but negative by immunoblot.
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Affiliation(s)
- J A Orden
- Departamento de Patología Animal I, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain
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12
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Hummel R, Devriese LA, Lehmann G. Characteristics of bovine Staphylococcus aureus with special regard to clumping factor activity. ZENTRALBLATT FUR BAKTERIOLOGIE : INTERNATIONAL JOURNAL OF MEDICAL MICROBIOLOGY 1992; 276:487-92. [PMID: 1611205 DOI: 10.1016/s0934-8840(11)80674-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The occurrence of the following groups of bovine Staphylococcus aureus with characteristic patterns of biochemical reactions and sensitivities to phages was confirmed by the present investigation of 662 isolates from the udders of cows in 53 dairy herds: (1) host-specific variety (v) bovis, (2) not alloted strains with the basic marker, crystal violet type A (group na CV A), (3) group na CV C. The latter was split into three subgroups clearly differing in phage susceptibility patterns: I/119, I without 119 and III, respectively. Lack of clumping factor activity occurred in 323 out of 346 (93%) phage pattern I/119 strains examined while most or all isolates of the other groups of bovine strains proved to be clumping-positive.
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Affiliation(s)
- R Hummel
- Robert Koch-Institut des Bundesgesundheitsamtes, Wernigerode
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13
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Orden JA, Cid D, Blanco ME, Ruiz Santa Quiteria JA, Gómez-Lucia E, de la Fuente R. Enterotoxin and toxic shock syndrome toxin-one production by staphylococci isolated from mastitis in sheep. APMIS 1992; 100:132-4. [PMID: 1554486 DOI: 10.1111/j.1699-0463.1992.tb00851.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
From 160 staphylococci isolated from ovine mastitis, 125 were identified as coagulase-positive staphylococci (CPS) and 35 as coagulase-negative staphylococci (CNS). Of these, 108 (87.8%) S. aureus produced at least one of the staphylococcal enterotoxins (SE) described. However, no CNS was found to be enterotoxigenic. Enterotoxin C (SEC) was the type most frequently produced. TSST-1 was shown to be produced by 91 (74.0%) of S. aureus, almost invariably in combination with SEC. Three CNS strains were also found to produce TSST-1 (two strains of S. xylosus and one strain of S. epidermidis).
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Affiliation(s)
- J A Orden
- Departamento de Patología Animal I (Sanidad Animal), Facultad de Veterinaria, Universidad Complutense, Madrid, Spain
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Lopes CA, Moreno G, Curi PR, Gottschalk AF, Modolo JR, Horacio A, Corrêa A, Pavan C. Characteristics of Staphylococcus aureus from subclinical bovine mastitis in Brazil. THE BRITISH VETERINARY JOURNAL 1990; 146:443-8. [PMID: 2224490 DOI: 10.1016/0007-1935(90)90033-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A total of 127 Staphylococcus aureus strains isolated from milk samples of cows with subclinical bovine mastitis was examined for biotype, phage pattern, in-vitro antibiotic susceptibilities and ability to produce enterotoxins. The majority of the strains showed features consistent with bovine rather than human origin. All strains were sensitive to the antibiotics tested, except penicillin and streptomycin. Enterotoxigenicity was observed in 6 (4.7%) strains and only enterotoxins A and C were produced.
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Affiliation(s)
- C A Lopes
- Department of Microbiology and Immunology, Estadual Paulista University, UNESP, Botucatu, Brazil
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15
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Valle J, Gomez-Lucia E, Piriz S, Goyache J, Orden JA, Vadillo S. Enterotoxin production by staphylococci isolated from healthy goats. Appl Environ Microbiol 1990; 56:1323-6. [PMID: 2339886 PMCID: PMC184403 DOI: 10.1128/aem.56.5.1323-1326.1990] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The ability of 342 staphylococcal isolates from different anatomical sites in healthy goats to produce staphylococcal enterotoxins (SE) was investigated. SE were produced by 74.3% of the 70 coagulase-positive strains and by 22% of the coagulase-negative strains studied. Most enterotoxigenic strains were isolated from the skin of udders and teats and from milk. SEC was the SE type most frequently produced, either alone (67.9%) or in combination with others. Five coagulase-negative species not previously reported as SE producers were identified (Staphylococcus chromogenes, S. warneri, S. sciuri, S. saprophyticus, and S. lentus). SEA, SEB, and SEC were detected in the milk of 17 of the 133 healthy goats studied. These results suggest that the goat is an important reservoir of enterotoxigenic staphylococci, most of which produce SEC.
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Affiliation(s)
- J Valle
- U.D. Microbiología e Inmunología, Facultade de Veterinaria, Universidad de Extremadura, Cáceres, Spain
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16
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Otero A, García ML, García MC, Moreno B, Bergdoll MS. Production of staphylococcal enterotoxins C1 and C2 and thermonuclease throughout the growth cycle. Appl Environ Microbiol 1990; 56:555-9. [PMID: 2306093 PMCID: PMC183377 DOI: 10.1128/aem.56.2.555-559.1990] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Synthesis of enterotoxins C1 and C2 and thermonuclease throughout the growth cycle was investigated with Staphylococcus aureus type strains FRI137 and FRI361 and S. aureus isolates M5 (C1) and L2 (C2) of animal origin. Both enterotoxins were produced during the exponential growth phase or at the beginning of the stationary phase. The minimal incubation time (7 to 12 h) and the lowest population (10(7) to 2 x 10(9) CFU/ml) associated with detectable enterotoxin (1 to 6.5 ng/ml) were related to the total amount of toxin produced after 24 h. Thermonuclease was detected in all samples whenever enterotoxins were detected. Furthermore, strain FRI137 produced thermonuclease earlier and at lower cell populations than it did enterotoxin C1. Patterns of enterotoxin and thermonuclease synthesis did not correlate. The concentration of toxins increased throughout the growth cycle, while the concentration of thermonuclease remained constant during the last hours of the growth cycle.
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Affiliation(s)
- A Otero
- Department of Food Hygiene and Food Technology, University of León, Spain
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17
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Gilmour A, Harvey J. Staphylococci in milk and milk products. SOCIETY FOR APPLIED BACTERIOLOGY SYMPOSIUM SERIES 1990; 19:147S-166S. [PMID: 2119062 DOI: 10.1111/j.1365-2672.1990.tb01805.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- A Gilmour
- Department of Agriculture for Northern Ireland, Belfast
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18
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Devriese LA. Staphylococci in healthy and diseased animals. SOCIETY FOR APPLIED BACTERIOLOGY SYMPOSIUM SERIES 1990; 19:71S-80S. [PMID: 2119067 DOI: 10.1111/j.1365-2672.1990.tb01799.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- L A Devriese
- Faculty of Veterinary Medicine, University of Gent, Belgium
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19
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Abstract
Cheese made from sheep milk was implicated in food-poisoning incidents in December 1984 and January 1985. Bacteriological examination of batches of cheese failed to reveal a viable pathogen but enterotoxin A produced by Staphylococcus aureus was present. This was the first time that enterotoxin was detected in a food produced in the UK which was associated with poisoning and from which viable Staph. aureus could not be isolated. Subsequent detailed examination of milk, yoghurt and cheese from the same producer revealed that contamination with Staph. aureus was associated with post-infection carriage as well as clinical illness in ewes on the farm. Strains producing enterotoxon. A were still intermittently present in the bulk milk used for cheese production nearly 2 years afterwards, apparently in the absence of clinical illness in the sheep. The possible effects of heat treatment are discussed. Any changes in legislation should cover all non-human mammalian milk used for human consumption.
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Affiliation(s)
- F J Bone
- Area Department of Bacteriology, Dumfries
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Affiliation(s)
- M Nuñez
- Departmento de Producción y Technología de Alimentos, Madrid, Spain
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21
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Hirooka EY, Müller EE, Freitas JC, Vicente E, Yoshimoto Y, Bergdoll MS. Enterotoxigenicity of Staphylococcus intermedius of canine origin. Int J Food Microbiol 1988; 7:185-91. [PMID: 3275321 DOI: 10.1016/0168-1605(88)90036-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Seventy-three staphylococcal strains isolated from pyrodermatitis in dogs were classified as Staphylococcus intermedius (52 strains) or Staphylococcus aureus (21 strains) on the basis of acetoin formation, anaerobic mannitol fermentation, aerobic maltose fermentation, pigmentation, coagulation of human plasma, and reaction on crystal violet agar. Enterotoxin was produced by 13 of the 52 S. intermedius strains and 6 of the S. aureus strains. The highest percentage of enterotoxigenic strains produced enterotoxins C (6 strains), D (7 strains), and E (6 strains). Four strains produced the toxic shock syndrome toxin-1. There was little difference in the antibiotic susceptibility between the enterotoxigenic and non-enterotoxigenic strains.
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Affiliation(s)
- E Y Hirooka
- Departmento de Patologia Geral, CCB, FUEL, Londrina, Brazil
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HÁJEK V, HORÁK V, BALUSEK J. Phage typing coagulase-positive staphylococci from rooks and gulls. Res Vet Sci 1988. [DOI: 10.1016/s0034-5288(18)30849-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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Otero A, García M, García M, Prieto M, Moreno B. Behaviour of Staphylococcus aureus strains, producers of enterotoxins C1or C2, during the manufacture and storage of Burgos cheese. J Appl Microbiol 1988. [DOI: 10.1111/j.1365-2672.1988.tb04424.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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24
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Bautista L, Gaya P, Medina M, Nuñez M. A quantitative study of enterotoxin production by sheep milk staphylococci. Appl Environ Microbiol 1988; 54:566-9. [PMID: 3355142 PMCID: PMC202492 DOI: 10.1128/aem.54.2.566-569.1988] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Of 124 staphylococcal strains isolated from sheep milk, 78 produced enterotoxin A, B, C, or D when evaluated by an enzyme-linked immunosorbent assay. Enterotoxins A and D, elaborated by 44 and 43 strains, respectively, showed the highest incidence. Enterotoxin production by coagulase-negative strains (one Staphylococcus cohnii, three S. epidermidis, five S. haemolyticus, and four S. xylosus) was detected. Linear and logarithmic-logarithmic regressions of optical density on enterotoxin concentration yielded the best-fitting equations for enterotoxin quantitation. A significantly higher incidence of enterotoxin producers and significantly higher levels of enterotoxins produced were recorded for coagulase-positive, thermostable nuclease-positive, hemolysis-positive, or mannitol-positive strains. Mannitol utilization was the best test for discriminating between enterotoxigenic and nonenterotoxigenic staphylococci.
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Affiliation(s)
- L Bautista
- Departamento de Bioquímica y Microbiología, INIA, Madrid, Spain
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Otero A, García MC, García ML, Prieto M, Moreno B. Behaviour of Staphylococcus aureus strains, producers of enterotoxins C1 or C2, during the manufacture and storage of Burgos cheese. THE JOURNAL OF APPLIED BACTERIOLOGY 1988; 64:117-22. [PMID: 3372397 DOI: 10.1111/j.1365-2672.1988.tb02730.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Burgos cheese was manufactured from pasteurized ewes' milk inoculated with Staphylococcus aureus strains FRI 137 and FRI 361, at levels of ca 10(3) and 10(5) cfu/ml and stored at 4 degrees, 10 degrees and 15 degrees C and at room temperature (10 degrees-15 degrees C). Populations of Staph. aureus and mesophilic aerobes, pH, and production of thermonuclease and enterotoxins C1 and C2 were investigated. Aerobic counts increased during cheese-making and storage. With both test strains, important growth was observed only during the storage period, the larger levels corresponding to the higher temperatures. Although Staph. aureus strains attained populations of over 10(8) cfu/g, no enterotoxin was detected. Strain FRI 361 reached 10(7) cfu/g without production of a detectable amount of thermonuclease. With strain FRI 137, the minimal population associated with enzyme activity was influenced by the inoculum size. Staphylococcus aureus counts are better indicators of staphylococcal growth in Burgos cheese than the thermonuclease test.
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Affiliation(s)
- A Otero
- Department of Food Hygiene and Food Microbiology, Veterinary Faculty, University of León, Spain
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26
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De Buyser M, Dilasser F, Hummel R, Bergdoll M. Enterotoxin and toxic shock syndrome toxin-1 production by staphylococci isolated from goat's milk. Int J Food Microbiol 1987. [DOI: 10.1016/0168-1605(87)90044-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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27
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Otero A, García MC, García ML, Moreno B. Production of staphylococcal enterotoxins C1 and C2 and thermonuclease in ewe's milk. Food Microbiol 1987. [DOI: 10.1016/s0740-0020(87)80008-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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28
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Bautista L, Bermejo MP, Nuñez M. Seasonal variation and characterization of Micrococcaceae present in ewes' raw milk. J DAIRY RES 1986; 53:1-5. [PMID: 3958289 DOI: 10.1017/s0022029900024596] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Samples (120) of ewes' raw milk collected over a 12-month period on arrival at the dairy and freshly drawn ewes' milk samples (30) collected at the farm were analysed for total viable counts and staphylococci. Total viable counts reached on the average 5.4 X 10(6)/ml in dairy samples and 6.0 X 10(5)/ml in farm samples, whereas mean levels of staphylococci were 5.9 X 10(4)/ml and 3.3 X 10(3)/ml, respectively. A high proportion (62%) of coagulase-positive isolates from Baird-Parker agar plates was detected in spring months. Staphylococcus aureus (42%), Staph. haemolyticus (23%) and Staph. epidermidis (10%) were the predominant species in 210 characterized isolates of staphylococci from ewes' raw milk. Seven coagulase-positive, maltose-negative staphylococci could not be identified with any of the recognized Staphylococcus species. Eighteen Micrococcus strains were identified as M. varians, whereas 111 Micrococcus strains of uncertain taxonomic status were separated into three groups, according to their physiological characters.
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Harvey J, Gilmour A. Application of current methods for isolation and identification of staphylococci in raw bovine milk. THE JOURNAL OF APPLIED BACTERIOLOGY 1985; 59:207-21. [PMID: 3902759 DOI: 10.1111/j.1365-2672.1985.tb01782.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Samples of raw milk were examined for counts of somatic cells, total viable bacteria, staphylococci (Schleifer & Kramer's medium) and Staphylococcus aureus (Baird-Parker medium, Baird-Parker medium with pig plasma and Baird-Parker medium with additional antibiotics). For the isolation of staphylococci from raw milk, Schleifer & Kramer's medium was found to be very selective and in general performed satisfactorily. From the results obtained with the three remaining media the continued use of Baird-Parker medium for isolation of Staph. aureus from raw milk is recommended with the proviso that colonies selected for identification should include those that clear and do not clear the egg yolk and are not limited to colonies with diameters greater than 1 mm. Staphylococci isolated from raw milk were identified by key tests using a multipoint inoculation procedure. A selected number were also examined by the API STAPH system in conjunction with the API LAB computer programme for identification of staphylococci. Of the staphylococci examined, 90.0% were identified using the multipoint procedure. For strains identified as Staph. aureus, Staph. hyicus subsp. hyicus, Staph. epidermidis, Staph. simulans, Staph. xylosus or members of the Staph. hominis/Staph. warneri/Staph haemolyticus group, the API system provided confirmatory evidence. With strains identified by the multipoint procedure as Staph. hyicus subsp. chromogenes, Staph. sciuri subsp. sciuri and Staph. sciuri subsp. lentus the API system did not always provide concurring results. Several strains which could not be identified by the multipoint procedure could be identified by the API system. Staph. aureus, Staph. hyicus subsp. hyicus and Staph. hyicus subsp. chromogenes strains isolated from milk were examined for production of enterotoxin A-E. Only 3.9% of Staph. aureus strains examined produced detectable enterotoxin (type C). None of the Staph. hyicus subsp. hyicus or Staph. hyicus subsp. chromogenes strains produced any of the known enterotoxins.
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Harvey J, Patterson JT, Gibbs PA. Enterotoxigenicity of Staphylococcus aureus strains isolated from poultry: raw poultry carcases as a potential food-poisoning hazard. THE JOURNAL OF APPLIED BACTERIOLOGY 1982; 52:251-8. [PMID: 7201999 DOI: 10.1111/j.1365-2672.1982.tb04847.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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