Enterotoxin production by strains of Staphylococcus aureus isolated from clinical and non-clinical specimens with special reference to enterotoxin F and toxic shock syndrome.

Enterotoxin production by strains of Staphylococcus aureus isolated from clinical specimens of human and animal origin and from healthy human carriers was investigated. All nine patients admitted to hospital with symptoms of toxic shock syndrome (TSS) yielded enterotoxin-producing strains of S. aureus. Eight of these produced staphylococcal enterotoxin F (SEF). A significantly smaller proportion of strains (42% of 50 strains tested) isolated from other clinical specimens of hospitalized patients produced SEF. Production of SEF by strains isolated from clinical specimens of animal origin (48 strains) was not observed. Twenty-nine per cent of 24 S. aureus strains isolated from noses of hospital staff produced SEF. This result was not significantly different from that obtained from strains isolated from clinical specimens other than TSS. A similar percentage of strains isolated from healthy human carriers outside hospital produced SEF (25% of 24 strains tested). The results indicated that enterotoxin production, especially that of SEF, is associated with S. aureus isolated from patients suspected of TSS. There was no indication of an association between S. aureus isolated from other staphylococcal infections and SEF production. All strains were phage typed and 79% of the strains belonging to the international phage-group I produced SEF. All strains lysed by phage 187 were found to produce SEF.     

Enterotoxin A and B production in strains of Staphylococcus aureus isolated from human beings and foods.

The production of enterotoxin A and B by strains of Staphylococcus aureus isolated from nasal swabs of healthy carriers, from lesions of hospital patients and from foods unconnected with outbreaks of food-poisoning was investigated. Sixty-six strains of S. aureus were obtained from human beings, two produced enterotoxin A, 45 produced enterotoxin B, seven produced enterotoxins A + B. Thirty-six strains were isolated from 111 samples of food, one produced enterotoxin A, 16 produced enterotoxin B. The relative incidence of A, B and A + B enterotoxigenicity was assessed.     

Enterotoxins and toxic-shock syndrome toxin-1 in non-enteric staphylococcal disease.

Over the 7 years 1985-91, 997 strains of Staphylococcus aureus from 962 patients with diseases other than food poisoning have been tested for the production of enterotoxins and toxic shock syndrome toxin-1 (TSST-1) and phage typed. In all, 128 cases could be classified as confirmed or probable toxic shock syndrome (TSS) but a further 199 cases were classified as possible or unconfirmed TSS. In 219 cases, an alternative diagnosis could be supported and 45 cases were classified as sudden infant death syndrome. In 371 cases, insufficient information for classification was available. Strains of phage group I producing TSST-1 were associated with menstrual TSS. Many menstrual TSS cases were aged less than 20 and were using non-introducer tampons. When all strains were reviewed, strong associations were observed between TSST-1 production and phage group I strains, enterotoxin B production and group V strains, enterotoxin C and phage-type 95 strains and between enterotoxin A without TSST-1 and phage group III strains.     

Growth and enterotoxin production of Staphylococcus aureus in shrimp.

Strains of Staphylococcus aureus isolated from shrimp were examined for phage pattern and enterotoxin production; 63% of the strains isolated from North Sea shrimp were typable with the International and additional set of phages, as were 38% of the strains isolated from South-East Asian shrimp. Staphylococcal enterotoxin(s) (SE) were produced by 48% and 35% of strains isolated from North Sea and South-East Asian shrimp respectively. Growth and enterotoxin production by S. aureus in shrimp was examined in storage experiments at 22 degrees C. S. aureus increased by 1-2 log units in 24 h when the organism was only a minor part of the total microflora of shrimp. When S. aureus was an equivalent part of the total flora its numbers increased by 3-4 log units in 24 h. Enterotoxins A and B became detectable when the number of S. aureus exceeded 10(7) per g in aseptically peeled shrimp. Results indicate that S. aureus is able to produce enterotoxin in shrimp, but its production depends upon a number of factors, including the relationship between S. aureus and competitive micro-organisms. It is concluded that the presence of S. aureus on commercially produced shrimp represents a potential hazard to health.     

Growth and enterotoxin production of Staphylococcus aureus in shrimp

Strains of Staphylococcus aureus isolated from shrimp were examined for phage pattern and enterotoxin production; 63% of the strains isolated from North Sea shrimp were typable with the International and additional set of phages, as were 38% of the strains isolated from South-East Asian shrimp. Staphylococcal enterotoxin(s) (SE) were produced by 48% and 35% of strains isolated from North Sea and South-East Asian shrimp respectively. Growth and enterotoxin production by S. aureus in shrimp was examined in storage experiments at 22 degrees C. S. aureus increased by 1-2 log units in 24 h when the organism was only a minor part of the total microflora of shrimp. When S. aureus was an equivalent part of the total flora its numbers increased by 3-4 log units in 24 h. Enterotoxins A and B became detectable when the number of S. aureus exceeded 10(7) per g in aseptically peeled shrimp. Results indicate that S. aureus is able to produce enterotoxin in shrimp, but its production depends upon a number of factors, including the relationship between S. aureus and competitive micro-organisms. It is concluded that the presence of S. aureus on commercially produced shrimp represents a potential hazard to health.     

Nasal carriage of enterotoxin-producing Staphylococcus aureus among restaurant workers in Kuwait City.

Enterotoxin-producing Staphylococcus aureus is a common cause of staphylococcal food poisoning. To determine the incidence of carriage of enterotoxin-producing S. aureus in a sample of the healthy population in Kuwait city, restaurant workers in the city were screened for nasal carriage of S. aureus. 26.6% of 500 workers studied carried S. aureus and 86.6% of the S. aureus produced staphylococcal enterotoxins. 28% produced enterotoxin A, 28.5% produced enterotoxin B, 16.4% produced enterotoxin C and 3.5% produced enterotoxin D. Ten isolates produced both enterotoxins A and B or A and C. 73% of the isolates were untypeable with standard phages. However, 17.1%, 3% and 6% belonged to phage groups I, II and III respectively. The results demonstrated a high level of enterotoxigenic S. aureus carriage among restaurant workers which although lower than that reported for the general population and hospital workers may be important in the restaurant industry.     

Evidence of enterotoxins and toxic shock syndrome toxin (TSST-1) in strains of Staphylococcus aureus isolated from various biological materials

Among 413 strains of S. aureus isolated from patients with chronic staphylococcal infections, from haemocultures in bacteriaemia and septic conditions, from gynaecological materials and nasal plugs of healthy carriers the authors detected the production of one or several types of enterotoxins in 124 strains (30.0%), production of TSST-1 in 19 strains (4.6%) and the concurrent production of enterotoxins and TSST-1 in 38 strains (9.2%). The highest ratio of toxigenic strains of S. aureus was found in departments (51.4%) and from hospitalized patients in blood cultures in bacteriaemias and septic conditions (41.2%). In a group of 184 strains from patients with chronic staphylococcal infection toxin production was proved in 49 strains (26.6%). Of 74 strains of S. aureus isolated from healthy carriers there were 16 toxigenic strains (21.6%). The most frequent type of enterotoxins were enterotoxins type A (26.7%) and C (24.4%). 21 strains (24.4%) produced more than one type of enterotoxins.     

Simultaneous occurrence of enterotoxigenic Staphylococcus aureus on the hands, mouth and feces of asymptomatic carriers

One hundred and twelve asymptomatic individuals were analysed with regard to the simultaneous incidence of Staphylococcus aureus on their hands and in their nose, mouth and stools, in the city of S. Paulo (Brazil). A total of 40 (35.7%) individuals were detected as carriers of this microorganism. Among these carriers, 27 (67.5%) were positive in only one of the four niches studied, 8 (20.0%) in two and 5 (12.5%) in three niches. They were identified 113 Staphylococcus aureus strains, and 28 (24.8%) of these strains, isolated from 9 (22.5%) carriers, produced enterotoxin. Of these strains, 7 (25.0%) produced type A enterotoxin, 6 (21.4%) of type B, 11 (39.3%) type C and 4 (14.3%) produced both type A and C. The phage typing of the 113 Staphylococcus aureus strains revealed the predominance of the strains lysed by phages belonging to the Group I/III/NC (16.8%). The results obtained did not demonstrate the simultaneous incidence of Staphylococcus aureus strains in samples collected from mouth, hands and stools of the group studied.     

日常食品及食物中毒样本中金黄色葡萄球菌肠毒素的分型检测分析

目的通过对北京市海淀区日常食品及食物中毒样本检出的金黄色葡萄球菌进行肠毒素分型检测,比较两种分离菌株的肠毒素分布差异。方法实验所用的金黄色葡萄球菌为2007-2012年海淀区日常食品和食物中毒样本中分离检出的菌株,依据GB 4789.10-2010采用ELISA方法测定金黄色葡萄球菌肠毒素(SEA-SEE)。结果 127株金黄色葡萄球菌中有108株肠毒素阳性,产肠毒素阳性率为85.0%。日常食品检出金黄色葡萄球菌93株,76株菌产肠毒素,产肠毒素阳性率为81.7%;食物中毒样本检出金黄色葡萄球菌34株,32株菌产肠毒素,产肠毒素阳性率为94.1%。产1种肠毒素和同时产3种肠毒素的菌株分别是47、37株,在产毒株中分别占43.5%和34.3%。食物中毒分离株产SEA和SED的比例(65.6%、65.6%)大于日常食品分离株(32.9%、30.3%).共有98株菌产SEE,在产毒株中占90.7%,肠毒素类型分布由高到低依次为E、A、D、C、B。结论食源性金黄色葡萄球菌产毒素能力较强,金黄色葡萄球菌食物中毒分离株和日常食品分离株在肠毒素分布上有差异。     

Enterotoxin production, phage typing and serotyping of Staphylococcus aureus strains isolated from clinical materials and food

The production of enterotoxins A, B, C and F by strains of Staphylococcus aureus isolated from various clinical sources and from isolates implicated in food poisoning was investigated. One hundred and ninety one of the 374 clinical strains (51.1%) were found to be enterotoxigenic; of these, 81 (27.7%) strains produced enterotoxin A, 57 (15.3%) strains produced enterotoxin B, 23 (6.2%) strains produced enterotoxin C, and 64 (17.1%) strains produced enterotoxin F. These enterotoxigenic strains were most frequently lysed by phages of group III (21.5%) or were not typable (22%). Eighteen of the 29 strains implicated in food poisoning were enterotoxigenic. The correlation of antigens and bacteriophage patterns with enterotoxigenicity was determined: enterotoxin A being related to a4 antigen, enterotoxin B to phages of 94/96 complex with c1, o antigens, and enterotoxin F to phages of group I with 2632, k1k2, m antigens.     

Enterotoxin production, phage typing and serotyping of Staphylococcus aureus strains isolated from clinical materials and food.

The production of enterotoxins A, B, C and F by strains of Staphylococcus aureus isolated from various clinical sources and from isolates implicated in food poisoning was investigated. One hundred and ninety one of the 374 clinical strains (51.1%) were found to be enterotoxigenic; of these, 81 (27.7%) strains produced enterotoxin A, 57 (15.3%) strains produced enterotoxin B, 23 (6.2%) strains produced enterotoxin C, and 64 (17.1%) strains produced enterotoxin F. These enterotoxigenic strains were most frequently lysed by phages of group III (21.5%) or were not typable (22%). Eighteen of the 29 strains implicated in food poisoning were enterotoxigenic. The correlation of antigens and bacteriophage patterns with enterotoxigenicity was determined: enterotoxin A being related to a4 antigen, enterotoxin B to phages of 94/96 complex with c1, o antigens, and enterotoxin F to phages of group I with 2632, k1k2, m antigens.     

Enterotoxin and toxic shock syndrome toxin-1 production of methicillin resistant and methicillin sensitive Staphylococcus aureus strains

In this study the production of enterotoxin A-D and toxic shock syndrome toxin-1 (TSST-1) of 181 methicillin resistant (MRSA) and 100 methicillin sensitive (MSSA) Staphylococcus aureus first isolates from different patients was investigated. All the MRSA- and MSSA isolates in the study were collected in a period between 1993 and 1995 from specimens sent from 11 different acute care hospitals in the greater Düsseldorf area. As far as possible the isolates were matched according to ward and hospital. The isolates were collected in the same time period and matched for specimen from which isolated. Furthermore, only first isolates were analysed in both groups. No significant difference in the production of toxin of any type between MRSA and MSSA could be detected (51 and 40% respectively). When the individual toxins were analysed, again no significant difference between MRSA and MSSA was demonstrable (enterotoxin production by MRSA 40% and MSSA 36%, and TSST-1 16% and 8% respectively). Despite this, a slight tendency for MRSA to produce enterotoxin A and B and for MSSA to produce enterotoxin C was observed. In addition, generation of TSST-1 by both groups was independent of enterotoxin A-D production. Interestingly, no increase in the proportion of TSST-1- or enterotoxin-producing MRSA and MSSA isolates was observed in strains isolated from blood cultures from patients with a clinical diagnosis of sepsis. Genotypical pulsed-field-gel-electrophoresis (PFGE) and phenotypical (bacteriophage typing, lysotyping) characterization of the 181 MRSA isolates resulted in 28 different PFGE patterns (of which 19 were toxin producers) and 22 lysotyping groups (18 of which produced toxin). In summary, the investigated clinical S. aureus isolates showed no difference in their ability to produce toxin and this was independent of their sensitivity to methicillin.     

Prevalence of icaA and icaD genes in Staphylococcus aureus and Staphylococcus epidermidis strains isolated from patients and hospital staff

Staphylococci are ubiquitous microorganisms that predominate in normal skin and mucosal flora. Staphylococcus aureus and Staphylococcus epidermidis have been identified as a major cause of nosocomial infections, especially in patients with predisposing factors such as indwelling or implanted foreign bodies. The ability of both S. epidermidis and S. aureus to produce biofilm was compared between 116 clinically significant strains (46 from blood cultures of patients with bloodstream infection and 70 isolated from catheters) and 60 strains isolated from nasal swabs of healthy carriers from hospital staff. The presence of the intercellular adhesion genes (icaA and icaD) was determined by the Polymerase Chain Reaction method, and slime production was examined using qualitative Congo red agar technique. Among clinical strains, 35.2% (19/54) of S. aureus and 48.4% (30/62) of S.epidermidis were both positive icaA and icaD and they produced slime. Among carrier strains, 22.2% (8/36) of S. aureus and 33.3% (8/24) of S. epidermidis were positive for slime synthesis and exhibited ica genes. Our results suggest that the virulence factors contributing to the development of infections can be present in patient and hospital staff isolates. Thus, we consider it is important to detect healthy carriers of slime-producing staphylococci and to control the dissemination of these microorganisms especially in a hospital.     

Studies on staphylococci from toxic shock syndrome in France, 1981-1983.

Staphylococci from 22 cases of toxic shock syndrome with onsets between 1981 and March 1983 have been studied. Another four cases were detected by abstract surveillance. Three of these patients died. The case histories show that the syndrome occurs in women during menstruation as well as in males and in children, and is associated with Staphylococcus aureus infections. The production of enterotoxins (A, B, C) and toxic shock toxin by S. aureus isolates from toxic shock syndrome was investigated. Twenty-two of the 23 isolates were found to be toxigenic: 7 produced enterotoxin A, 8 produced enterotoxin B, 3 produced enterotoxin C and 13 produced toxic shock toxin. The latter was found with enterotoxin A in five cases, and with enterotoxins A and B in only one case. Sixty-three percent of 46 S. aureus strains isolated from the vagina of patients with diseases other than toxic shock syndrome produced toxin; eight of these strains produced toxic shock toxin.     

Studies on staphylococci from toxic shock syndrome in France, 1981-1983

Staphylococci from 22 cases of toxic shock syndrome with onsets between 1981 and March 1983 have been studied. Another four cases were detected by abstract surveillance. Three of these patients died. The case histories show that the syndrome occurs in women during menstruation as well as in males and in children, and is associated with Staphylococcus aureus infections. The production of enterotoxins (A, B, C) and toxic shock toxin by S. aureus isolates from toxic shock syndrome was investigated. Twenty-two of the 23 isolates were found to be toxigenic: 7 produced enterotoxin A, 8 produced enterotoxin B, 3 produced enterotoxin C and 13 produced toxic shock toxin. The latter was found with enterotoxin A in five cases, and with enterotoxins A and B in only one case. Sixty-three percent of 46 S. aureus strains isolated from the vagina of patients with diseases other than toxic shock syndrome produced toxin; eight of these strains produced toxic shock toxin.     

Staphylococcus aureus of phage type 187 isolated from people occurred to be a genes carrier of eneterotoxin C and toxic shock syndrome toxin-1 (TSST-1)

The aim of this study was to examine the genotype properties of Staphylococcus aureus of phage type 187 strains that constitute a separate group among the strains of S. aureus. Sixteen strains were collected from the hospital patients (n=12) and the healthy carriers (n=4) in 13 medical centres in Poland during 1991 and 2005. Biotyping, antibiotic susceptibility, phage typing, detection the genes of enterotoxins and toxic shock syndrome toxin, genotyping of chromosomal DNA by pulsed-field gel electrophoresis (PFGE), also amplification and restriction analysis of the coagulase (coa) and the protein A genes (spa) (PCR/restriction fragment length polymorphism (RFLP)) was tested. The results of this study showed that all staphylococcus of phage type 187 belonged to the human biotype (A) and appeared to be sensitive to all of the tested antibiotics, including methicillin (MSSA). Finding out the toxin genes showed that almost all of them (93.8%) had the enterotoxin C gene (sec) and TSST-1 gene (tst). The PFGE typing proved that the phage type 187 strains (except for one) constitute one PFGE type. These results and the identical restriction patterns in the PCR/RFLP method, also the same biotype, sensitivity to antibiotics and the presence genes of the same type of toxins confirmed that the phage type 187 strains constitute one clone within our country. Additionally, the fact that almost all of them have the enterotoxin genes and tst gene allows to consider them the strains of potentially high virulence.     

Phenotypic characterization and prevalence of enterotoxin genes in Staphylococcus aureus isolates from outbreaks of illness in Chengdu City

Staphylococcus aureus produces a spectrum of enterotoxin that is recognized as the main reason for causing staphylococcal food poisoning. The aim of the current study was to investigate the phenotypic characteristics and enterotoxin genotypes of S. aureus isolated from food poisoning sufferers. On the basis of the amplification of 16S rRNA and nuc gene specific to S. aureus assay and the phenotype (hemolytic activity, thermal stable nuclease [Tnase] test, and biofilm formation), all isolates were identified as S. aureus. To genotypically characterize S. aureus isolates, genes encoding staphylococcal enterotoxin (sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sem, sen, ser, and seu) were investigated by using polymerase chain reaction technique. The results showed that the eight isolates of S. aureus had different enterotoxin genotypic characteristics, which was the main cause of food poisoning. One isolate contained 10 enterotoxin genes, and the other 7 isolates carried 3 or more enterotoxin genes. The frequency of the newly identified enterotoxin genes (seg-seu) was higher than classical genes (sea-see). Overall, multi-gene detection rates were 75% (for sek, ser, and seu); 50% (for sea and sem); 37.5% (for sen, seg, and sei); and 12.5% (for seb, sec, sed, and sej), respectively. The see and seh gene were not detected in any isolates. The current study provided the exact distribution of enterotoxin genes in eight S. aureus strains from food poisoning sufferers, which indicated that the pathogenicity of the newly identified enterotoxin should be highlighted. The need for prevention of food poisoning occurrences caused by enterotoxin of S. aureus should be reinforced.     

一起金黄色葡萄球菌食物中毒病原学检测及耐药分析

目的实验室检测分析福州市一起食物中毒的病原菌及耐药情况。方法参照WS/T 81-1996、WS/T 13-1996、WS/T 80-1996、WS 271-2007附录B2和GB/T 4789. 5-2012标准。结果该起食物中毒标本共检出3株金黄色葡萄球菌。这些菌株均产肠毒素,其中ZD2017-13和ZD2017-14 2株菌产肠毒素C,ZD2017-16产肠毒素B。这3株菌均为耐甲氧西林金黄色葡萄球菌(MARS),均对头孢西丁、氨苄西林、苯唑西林和青霉素耐药。结论从该起食物中毒标本中分离得到的金黄色葡萄球菌均产肠毒素,为耐甲氧西林金黄色葡萄球菌,且对多种抗生素耐药。     

2013-2017年西安市食物中毒中金黄色葡萄球菌分型分析

  目的  了解2013-2017年西安市食物中毒中分离的金黄色葡萄球菌（staphylococcus aureus,S.aureus）分子流行特点。  方法  通过脉冲场凝胶电泳（pulsed field gel electrophoresis,PFGE）、多位点序列分型（multilocus sequence typing,MLST）和spa分型方法对八起食物中毒标本的26株金黄色葡萄球菌进行分子分型,运用聚合酶链式反应（polymerase chain reaction,PCR）检测相关肠毒素基因。  结果  26株S.aureus PFGE可分为7种型别（A-G）;MLST可分为3种序列型（ST6,ST5和ST59）。其中,ST6占65.38%,为主要型别;spa可分为4种型别（t437,t701,t11363和t5923）,优势型别为t701,占65.38%。肠毒素基因检测中,sea基因占76.92%（20/26）;sed-seg基因占23.08%（6/26）;其它肠毒素基因未检出。  结论  2013-2017年西安市食物中毒标本中分离培养的S.aureus的主要流行型别为ST6-t701-sea,并首次检出含有seg新型肠毒素基因。PFGE、MLST和spa分型三种方法相结合全面的了解菌株的分子流行特点。     

Irish-1 and Irish-2: UK epidemic meticillin-resistant Staphylococcus aureus strains associated with Northern Ireland

Since 1998, an increasing number of meticillin-resistant Staphylococcus aureus (MRSA) isolates with one of two characteristic phage patterns have been referred to the authors' laboratory from Northern Ireland. These strains were designated 'Irish-1' and 'Irish-2'. Analysis of 956 submitted isolates classified as Irish-1 or Irish-2 showed that 97% of the former and 95% of the latter were from Northern Ireland. Only 0.2% and 3%, respectively, were from England. Eleven Irish-2 isolates had been referred from Western Australia as representatives of an epidemic strain originally isolated there in 1994. Ninety isolates with the Irish-1 phage pattern and 91 isolates with the Irish-2 phage pattern, from numerous hospitals, were characterized by SmaI pulsed-field gel electrophoresis (PFGE), toxin gene carriage and antibiotic susceptibility. PFGE showed that, within each collection, a few isolates represented unrelated strains, but the majority were within six band differences of the most common profiles. Half of the Irish-1 isolates were homogeneous, with 22 DNA profiles among the remainder. Irish-2 isolates had two common profiles, D1 and D2, equally divided between one-third of the isolates and differing from each other by two bands; the remaining isolates shared 31 DNA profiles. Cluster analysis showed some overlap in DNA profiles between the Irish-1 and Irish-2 strains, but clear separation from other epidemic MRSA strains. There was no obvious correlation between PFGE profile and either antibiotic resistance pattern or toxin gene possession. All but three Irish-1 isolates possessed only the staphylococcal enterotoxin A (sea) gene, whereas almost all Irish-2 isolates were negative for all 12 enterotoxin genes. Sixty-nine percent of Irish-2 isolates were resistant to ciprofloxacin, erythromycin, kanamycin, neomycin and streptomycin, while 90% of Irish-1 isolates were resistant to all these plus gentamicin and mupirocin. All isolates were sensitive to quinupristin/dalfopristin, teicoplanin and vancomycin. Urease production was negative in both strains. The results suggest that Irish-1 and Irish-2 are distinct epidemic strains, identifiable by phage typing, DNA profiles, antibiotic resistance and toxin gene carriage.