1
|
Prevalence and Virulence Determinants of Staphylococcus aureus in Wholesale and Retail Pork in Wuhan, Central China. Foods 2022; 11:foods11244114. [PMID: 36553856 PMCID: PMC9777741 DOI: 10.3390/foods11244114] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/11/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022] Open
Abstract
Staphylococcus aureus is one of the major foodborne pathogens and can cause serious foodborne illness in humans by foods contaminated with S. aureus enterotoxins. In recent years, livestock-associated S. aureus has been a major public health concern for humans and has emerged in various countries globally. China is one of the largest producers of pigs and pork in the world. However, there are few studies on the detailed genotypic and pathogenic characterization of pork-associated S. aureus in China. In this study, the prevalence, antimicrobial resistance, and genotypic characteristics of S. aureus in raw pork in Wuhan, China, were investigated through multilocus sequence typing (MLST), staphylococcal protein A gene (spa) typing, and whole-genome sequencing analysis. A total of 518 S. aureus isolates (16.9%) were isolated from 3067 retail and wholesale pork samples. The prevalence of S. aureus in retail pork (22.7%) was significantly higher than in wholesale pork (15.1%), while the proportion of multidrug-resistant (MDR) isolates in wholesale pork (12.9%) was significantly higher than in retail pork (6.2%). Among the isolates, 10.8% were resistant to three or more antibiotics, with higher rates of resistance to penicillin (88.8%) and erythromycin (58.1%). A total of 28 sequence types (STs) were identified in the 518 isolates, and the predominant type was ST7 (57.5%), followed by ST5 (9.1%). In addition, based on the whole-genome sequences of 39 representative strains, 17 spa types were identified among the isolates, of which t899, t091, and t437 were the most common. Furthermore, 19 staphylococcal enterotoxin (SE) and SE-like (SEl) toxin genes were detected in the isolates, of which selw was the most common type (100%), followed by sei, sem, seo, seu, and selv (46.2%); sey (35.9%); and sea, seg, and sen (33.3%). This study found for the first time that ST7-t091-selw and ST9-t899-SCCmecXII-selw were the predominant genotypes of S. aureus in pork in China, which indicated the spreading of S. aureus with multiple virulence factors, especially with new SE/SEl types in pigs and pork, is a serious new challenge for food safety. Good hygiene and good production practices to prevent interspecies transmission and cross-contamination of S. aureus in the pig-pork chain are of great significance to public health.
Collapse
|
2
|
Naik P, Naik MN, Mishra DK, Joseph J. Methicillin resistance in Staphylococcus aureus modulates the transcriptome and disease pathology in a murine model of endophthalmitis. Exp Eye Res 2022; 218:109016. [DOI: 10.1016/j.exer.2022.109016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 02/05/2022] [Accepted: 02/24/2022] [Indexed: 11/16/2022]
|
3
|
Shimamura Y, Yui T, Horiike H, Masuda S. Toxicity of combined exposure to acrylamide and Staphylococcus aureus. Toxicol Rep 2022; 9:876-882. [DOI: 10.1016/j.toxrep.2022.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 04/17/2022] [Accepted: 04/18/2022] [Indexed: 11/26/2022] Open
|
4
|
Umeda K, Ono HK, Wada T, Motooka D, Nakamura S, Nakamura H, Hu DL. High production of egc2-related staphylococcal enterotoxins caused a food poisoning outbreak. Int J Food Microbiol 2021; 357:109366. [PMID: 34454396 DOI: 10.1016/j.ijfoodmicro.2021.109366] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/12/2021] [Accepted: 08/16/2021] [Indexed: 10/20/2022]
Abstract
Staphylococcal enterotoxins (SEs) produced by enterotoxigenic Staphylococcus aureus in food cause staphylococcal food poisoning. We recently reported a foodborne outbreak due to S. aureus harboring new SE/SE-like (SEl) genes (seg, sei, sem, sen, seo, and selu) related to enterotoxin gene cluster (egc) 2 as with other research groups. However, the pathogenicity of SEs production remains unclear. Therefore, we herein investigated egc2-related SEs production from S. aureus isolates and leftover food items during a foodborne outbreak using a sandwich enzyme-linked immunosorbent assay suitable for the quantification of SEs. S. aureus isolates produced markedly high levels of egc2-related SEs, and the leftover food item "Sushi" contained SEs over the toxin dose that causes food poisoning symptoms. A representative isolate was subjected to whole-genome sequencing. The isolate was homologous with previously reported ST45 strains, particularly the unique genomic island νSaβ structure mostly consisting of egc2. The present study indicates that egc2-related SEs are food poisoning causative agents based on high SE production levels within an actual foodborne outbreak.
Collapse
Affiliation(s)
- Kaoru Umeda
- Division of Microbiology, Osaka Institute of Public Health, 8-34 Tojo-cho, Tennoji-ku, Osaka 543-0026, Japan.
| | - Hisaya K Ono
- Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, 23-35-1 Higashi, Towada City, Aomori 034-8628, Japan
| | - Takayuki Wada
- Graduate School of Human Life Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Daisuke Motooka
- Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita City, Osaka 565-0871, Japan
| | - Shota Nakamura
- Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita City, Osaka 565-0871, Japan
| | - Hiromi Nakamura
- Division of Microbiology, Osaka Institute of Public Health, 8-34 Tojo-cho, Tennoji-ku, Osaka 543-0026, Japan
| | - Dong-Liang Hu
- Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, 23-35-1 Higashi, Towada City, Aomori 034-8628, Japan
| |
Collapse
|
5
|
Hu DL, Li S, Fang R, Ono HK. Update on molecular diversity and multipathogenicity of staphylococcal superantigen toxins. ANIMAL DISEASES 2021. [DOI: 10.1186/s44149-021-00007-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
AbstractStaphylococcal superantigen (SAg) toxins are the most notable virulence factors associated with Staphylococcus aureus, which is a pathogen associated with serious community and hospital acquired infections in humans and various diseases in animals. Recently, SAg toxins have become a superfamily with 29 types, including staphylococcal enterotoxins (SEs) with emetic activity, SE-like toxins (SEls) that do not induce emesis in primate models or have yet not been tested, and toxic shock syndrome toxin-1 (TSST-1). SEs and SEls can be subdivided into classical types (SEA to SEE) and novel types (SEG to SElY, SE01, SE02, SEl26 and SEl27). The genes of SAg toxins are located in diverse accessory genetic elements and share certain structural and biological properties. SAg toxins are heat-stable proteins that exhibit pyrogenicity, superantigenicity and capacity to induce lethal hypersensitivity to endotoxin in humans and animals. They have multiple pathogenicities that can interfere with normal immune function of host, increase the chances of survival and transmission of pathogenic bacteria in host, consequently contribute to the occurrence and development of various infections, persistent infections or food poisoning. This review focuses on the following aspects of SAg toxins: (1) superfamily members of classic and novelty discovered staphylococcal SAgs; (2) diversity of gene locations and molecular structural characteristics; (3) biological characteristics and activities; (4) multi-pathogenicity of SAgs in animal and human diseases, including bovine mastitis, swine sepsis, abscesses and skin edema in pig, arthritis and septicemia in poultry, and nosocomial infections and food-borne diseases in humans.
Collapse
|
6
|
High Titer Persistent Neutralizing Antibodies Induced by TSST-1 Variant Vaccine Against Toxic Shock Cytokine Storm. Toxins (Basel) 2020; 12:toxins12100640. [PMID: 33023185 PMCID: PMC7601046 DOI: 10.3390/toxins12100640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 09/17/2020] [Accepted: 09/29/2020] [Indexed: 12/25/2022] Open
Abstract
Staphylococcal superantigen toxins lead to a devastating cytokine storm resulting in shock and multi-organ failure. We have previously assessed the safety and immunogenicity of a recombinant toxic shock syndrome toxin 1 variant vaccine (rTSST-1v) in clinical trials (NCT02971670 and NCT02340338). The current study assessed neutralizing antibody titers after repeated vaccination with escalating doses of rTSST-1v. At study entry, 23 out of 34 subjects (67.6%) had neutralizing antibody titers inhibiting T cell activation as determined by 3H-thymidine incorporation at a serum dilution of ≤1:100 with similar figures for inhibition of IL-2 activation (19 of 34 subjects, 55.9%) as assessed by quantitative PCR. After the first vaccination, numbers of subjects with neutralization titers inhibiting T cell activation (61.7% ≥ 1:1000) and inhibiting IL-2 gene induction (88.2% ≥ 1:1000) increased. The immune response was augmented after the second vaccination (inhibiting T cell activation: 78.8% ≥ 1:1000; inhibiting IL-2 induction: 93.9% ≥ 1:1000) corroborated with a third immunization months later in a small subgroup of subjects. Assessment of IFNγ, TNFα and IL-6 inhibition revealed similar results, whereas neutralization titers did not change in placebo participants. Antibody titer studies show that vaccination with rTSST-1v in subjects with no/low neutralizing antibodies can rapidly induce high titer neutralizing antibodies persisting over months.
Collapse
|
7
|
Chajęcka-Wierzchowska W, Gajewska J, Wiśniewski P, Zadernowska A. Enterotoxigenic Potential of Coagulase-Negative Staphylococci from Ready-to-Eat Food. Pathogens 2020; 9:pathogens9090734. [PMID: 32899905 PMCID: PMC7559265 DOI: 10.3390/pathogens9090734] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/01/2020] [Accepted: 09/04/2020] [Indexed: 11/16/2022] Open
Abstract
Although coagulase-positive staphylococci are considered to be the main factor responsible for food poisoning, an increasing role for the coagulase-negative staphylococci in the production of enterotoxins has been observed in recent years. This study was conducted to assess the occurrence of genes responsible for the production of staphylococcal enterotoxins (SE), enterotoxin-like toxins (SEI) and toxic shock syndrome toxin-1 (TSST-1) in coagulase-negative staphylococci (CoNS) isolated from ready-to-eat food from bars and restaurants. One hundred and eighteen CoNS strains were tested using polymerase chain reaction (PCR) to five superantigenic toxin genes, including five different types of classical enterotoxins (sea, seb, sec, sed and see) and the toxic shock syndrome toxin-1 (tsst-1) as well as to supertoxin-like genes. PCR-positive isolates were then tested using immunoenzymatic methods (SET-RPLA, Vidas SET 2) for toxin expression. Out of 118 CoNS strains, the presence of staphylococcal enterotoxins was confirmed in 72% of them. The most frequently found enterotoxin-like genotype was ser, selu. Two of the tested strains had up to ten different enterotoxin genes in the genome at the same time. Although no production of enterotoxins was detected in the CoNS, which means that their possible role in the epidemiology of food-borne diseases is minimal, the data demonstrated that the toxigenic capacity of the CoNS should not be ignored, and that this group of microorganisms should be continuously monitored in food.
Collapse
|
8
|
Aung MS, Urushibara N, Kawaguchiya M, Ito M, Habadera S, Kobayashi N. Prevalence and Genetic Diversity of Staphylococcal Enterotoxin (-Like) Genes sey, selw, selx, selz, sel26 and sel27 in Community-Acquired Methicillin-Resistant Staphylococcus aureus. Toxins (Basel) 2020; 12:toxins12050347. [PMID: 32456224 PMCID: PMC7291287 DOI: 10.3390/toxins12050347] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 01/09/2023] Open
Abstract
Staphylococcal enterotoxins (SEs) are virulence factors of Staphylococcus aureus associated with various toxic diseases due to their emetic and superantigenic activities. Although at least 27 SE(-like) genes have been identified in S. aureus to date, the newly identified SE(-like) genes have not yet been well characterized by their epidemiological features. In this study, the prevalence and genetic diversity of SE gene sey and SE-like genes selw, selx, selz, sel26, and sel27 were investigated for 624 clinical isolates of community-acquired methicillin-resistant S. aureus (CA-MRSA). The most prevalent SE(-like) gene was selw (92.9%), followed by selx (85.6%), sey (35.4%) and selz (5.6%), while sel26 and sel27 were not detected. Phylogenetically, sey, selw, selx, and selz were discriminated into 7, 10, 16, and 9 subtypes (groups), respectively. Among these subtypes, sey was the most conserved and showed the highest sequence identity (>98.8%), followed by selz and selx. The SE-like gene selw was the most divergent, and four out of ten genetic groups contained pseudogenes that may encode truncated product. Individual subtypes of SE(-like) genes were generally found in isolates with specific genotypes/lineages of S. aureus. This study revealed the putative ubiquity of selw and selx and the prevalence of sey and selz in some specific lineages (e.g., ST121) in CA-MRSA, suggesting a potential role of these newly described SEs(-like) in pathogenicity.
Collapse
Affiliation(s)
- Meiji Soe Aung
- Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan; (N.U.); (M.K.); (N.K.)
- Correspondence: ; Tel.: +81-11-611-2111
| | - Noriko Urushibara
- Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan; (N.U.); (M.K.); (N.K.)
| | - Mitsuyo Kawaguchiya
- Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan; (N.U.); (M.K.); (N.K.)
| | - Masahiko Ito
- Sapporo Clinical Laboratory, Inc., Sapporo 060-0005, Japan; (M.I.); (S.H.)
| | - Satoshi Habadera
- Sapporo Clinical Laboratory, Inc., Sapporo 060-0005, Japan; (M.I.); (S.H.)
| | - Nobumichi Kobayashi
- Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo 060-8556, Japan; (N.U.); (M.K.); (N.K.)
| |
Collapse
|
9
|
Interleukin-10 (IL-10) Produced by Mutant Toxic Shock Syndrome Toxin 1 Vaccine-Induced Memory T Cells Downregulates IL-17 Production and Abrogates the Protective Effect against Staphylococcus aureus Infection. Infect Immun 2019; 87:IAI.00494-19. [PMID: 31358568 DOI: 10.1128/iai.00494-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 07/23/2019] [Indexed: 11/20/2022] Open
Abstract
Development of long-term memory is crucial for vaccine-induced adaptive immunity against infectious diseases such as Staphylococcus aureus infection. Toxic shock syndrome toxin 1 (TSST-1), one of the superantigens produced by S. aureus, is a possible vaccine candidate against infectious diseases caused by this pathogen. We previously reported that vaccination with less toxic mutant TSST-1 (mTSST-1) induced T helper 17 (Th17) cells and elicited interleukin-17A (IL-17A)-mediated protection against S. aureus infection 1 week after vaccination. In the present study, we investigated the host immune response induced by mTSST-1 vaccination in the memory phase, 12 weeks after the final vaccination. The protective effect and IL-17A production after vaccination with mTSST-1 were eliminated because of IL-10 production. In the presence of IL-10-neutralizing monoclonal antibody (mAb), IL-17A production was restored in culture supernatants of CD4+ T cells and macrophages sorted from the spleens of vaccinated mice. Vaccinated mice treated with anti-IL-10 mAb were protected against systemic S. aureus infection in the memory phase. From these results, it was suggested that IL-10 produced in the memory phase suppresses the IL-17A-dependent vaccine effect through downregulation of IL-17A production.
Collapse
|
10
|
Huang TM, Chou CC. Methicillin-sensitive and methicillin-resistant Staphylococcus aureus strains and their toxin genes in the nostrils of dogs and workers at an animal shelter. J Appl Microbiol 2019; 126:1899-1909. [PMID: 30924987 DOI: 10.1111/jam.14266] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 03/16/2019] [Accepted: 03/23/2019] [Indexed: 11/30/2022]
Abstract
AIMS Methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA, respectively) in the nostrils of dogs and workers at an animal shelter were cultured. Staphylococcal toxin genes were analysed to identify potential health concerns. METHODS AND RESULTS Samples were obtained from 441 dogs and 9 workers. The respective isolation rates of S. aureus and MRSA were 49·0% (216/441) and 1·6% (7/441) for shelter dogs and 44·4% (4/9) and 33·3% (3/9) for workers, respectively. Isolation of S. aureus in summer (61·9%) and in adult dogs (59·2%) were significantly higher than those in winter (35·8%) and in juvenile dogs (33·3%) (P < 0·001), respectively. The predominant enterotoxin genotypes and combination profiles of S. aureus were (sea, seb, seg, sei, sem, sen, seo, seu) and (sea, sea-seb, and seg-sei-sem-sen-seo-seu), respectively, and 20% of isolates carried food poisoning-associated enterotoxins. The se profiles in shelter dogs were different from those in general pet dogs and their owners. MRSA isolates were identified as SCCmec IV and VII, and they shared se combination profiles of (sec-seg-sei-sel-sem-sen-seo-seu) and (seb-sek-seq). MRSA in this shelter had similar microbiological characteristics as those reported in CA-MRSA ST59 in humans. CONCLUSIONS Human health-associated bacteria and food poisoning-related toxin genes were identified. Further evaluations of health concerns in animal shelters are necessary. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first study to focus on se prevalence and MRSA characteristics in an animal shelter in Taiwan. The MRSA characteristics determined in this study were similar to those of CA-MRSA strains isolated from communities in the past, indicating potential health risks in cities.
Collapse
Affiliation(s)
- T-M Huang
- Department of Veterinary Medicine, National Taiwan University, Taipei, Taiwan
| | - C-C Chou
- Department of Veterinary Medicine, National Taiwan University, Taipei, Taiwan
| |
Collapse
|
11
|
Niek WK, Teh CSJ, Idris N, Thong KL, Ponnampalavanar S. Predominance of ST22-MRSA-IV Clone and Emergence of Clones for Methicillin-Resistant Staphylococcus aureus Clinical Isolates Collected from a Tertiary Teaching Hospital Over a Two-Year Period. Jpn J Infect Dis 2019; 72:228-236. [PMID: 30814457 DOI: 10.7883/yoken.jjid.2018.289] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common nosocomial pathogens, causing mild to severe infections. This study aimed to determine the genotypic and phenotypic characteristics of clinical MRSA isolates collected from a teaching hospital from 2014 - 2015. These isolates were genotyped by multilocus sequence typing, staphylococcal cassette chromosomal mec (SCCmec) typing, virulence genes detection, and pulsed-field gel electrophoresis; they were phenotyped based on their antibiotics susceptibility profiles. The most prevalent sequence type was ST22. ST3547 was identified from a blood isolate from 2015. Three SCCmec types (III in 26.26%, IV in 70.71%, and V in 3.03% isolates) were detected. Agr type I, II, and III were also detected among the isolates. The most prevalent virulence genes found were hemolysin (100%) and intracellular adhesion (91.9%). At least one staphylococcal enterotoxin was detected in 83 (83.8%) isolates. All the isolates were susceptible to vancomycin (minimum inhibitory concentration ≤ 2 μg/mL). Statistical analysis revealed a significant increase in hypertension (p = 0.035), dyslipidemia and obesity (p = 0.046), and previous exposure to any quinolone (p = 0.010) cases over the two-year period. The emergence and circulation of community-associated MRSA variants were observed in our hospital.
Collapse
Affiliation(s)
- Wen Kiong Niek
- Department of Medical Microbiology, University of Malaya
| | | | - Nuryana Idris
- Department of Medical Microbiology, University of Malaya
| | - Kwai Lin Thong
- Institute of Biological Science, Faculty of Science, University of Malaya
| | | |
Collapse
|
12
|
Arabestani MR, Rastiyani S, Alikhani MY, Mousavi SF. The Relationship Between Prevalence of Antibiotics Resistance and Virulence Factors Genes of MRSA and MSSA Strains Isolated from Clinical Samples, West Iran. Oman Med J 2018; 33:134-140. [PMID: 29657682 DOI: 10.5001/omj.2018.25] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Objectives We sought to evaluate the relationship between the prevalence of antibiotics resistance and virulence factors genes in methicillin-resistant Staphylococcal aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) strains from clinical samples taken in west Iran. Methods We performed a cross-sectional study using 100 MRSA and 100 MSSA samples isolated from clinical specimens. We used biochemical methods to identify the isolates, which were confirmed by the polymerase chain reaction (PCR) assay. Antibiotic susceptibility testing was performed using disk diffusion. PCR detected the presence of virulence factors, including enterotoxin genes, toxic shock syndrome toxin-1 (TSST-1), and exfoliative toxin. Results The majority of MRSA isolates exhibited a high level of resistance to common antibiotics and susceptible to vancomycin, while most MSSA isolates were also resistant to erythromycin and ciprofloxacin. The prevalence of Staphylococcal enterotoxins (SEs) were reported 147 (73.5%). Among 100 MRSA samples, 92 (92.0%) harbored SAg genes. The most frequent toxin gene was sea (45.0%) followed by sec (39.0%). Among 100 MSSA isolates, 89 (89.0%) harbored SAg genes and the most prevalent genes were sea (42.0%), sek (38.0%), sec (35.0%,), and TSST-1 (10.0%). The prevalence of TSST-1 and exfoliative toxin genes in MRSA samples were 12 (12.0%). The association of SAg genes with MRSA and MSSA isolates showed a high prevalence of enterotoxin seq, seg, and sei in MRSA than MSSA with a statistically significant difference (p < 0.050). Conclusions The prevalence of MRSA and the association of pathogenic agents with antibiotics resistance genes can lead to the emergence of strains with higher pathogenicity and less susceptibility.
Collapse
Affiliation(s)
- Mohammad Reza Arabestani
- Department of Microbiology, Hamadan University of Medical Sciences, Hamadan, Iran.,Nutrition Health Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Sahar Rastiyani
- Department of Microbiology, Hamadan University of Medical Sciences, Hamadan, Iran
| | | | | |
Collapse
|
13
|
Hu DL, Ono HK, Isayama S, Okada R, Okamura M, Lei LC, Liu ZS, Zhang XC, Liu MY, Cui JC, Nakane A. Biological characteristics of staphylococcal enterotoxin Q and its potential risk for food poisoning. J Appl Microbiol 2017; 122:1672-1679. [PMID: 28375567 DOI: 10.1111/jam.13462] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 03/08/2017] [Accepted: 03/24/2017] [Indexed: 11/30/2022]
Abstract
AIMS To elucidate the biological characteristics and stability of a newly identified staphylococcal enterotoxin Q (SEQ) against heating and digestive enzymes and to evaluate the risk of seq-harbouring Staphylococcus aureus in food poisoning. METHODS AND RESULTS Purified SEQ was treated with heating, pepsin and trypsin which are related to food cooking, stomach and intestine conditions, respectively. Superantigenic activity of SEQ was assessed by determining the ability of IL-2 induction in mouse spleen cells. The emetic activity of SEQ was assessed using house musk shrew, a small emetic animal model. The results revealed that SEQ exhibits a remarkable resistance to heat treatment and pepsin digestion and has significant superantigenic and emetic activities. Furthermore, a sandwich ELISA for detection of SEQ production was developed, and the results showed that seq-harboring S. aureus isolates produce a large amount of SEQ. CONCLUSIONS The newly identified SEQ had remarkable stability to heat treatment and digestive enzyme degradation and exhibited significant superantigenic and emetic activities. In addition, seq-harbouring S. aureus isolated from food poisoning outbreaks produced a large amount of SEQ, suggesting that seq-harbouring S. aureus could potentially be a hazard for food safety. SIGNIFICANCE AND IMPACT OF THE STUDY This study found, for the first time, that SEQ, a nonclassical SE, had remarkable stability to heat treatment and enzyme degradation and exhibited significant emetic activity, indicating that SEQ is a high-risk toxin in food poisoning.
Collapse
Affiliation(s)
- D-L Hu
- College of Veterinary Medicine, Jilin University, Changchun, Jiling, China.,Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan.,Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - H K Ono
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan.,Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | - S Isayama
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan
| | - R Okada
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan
| | - M Okamura
- Department of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan
| | - L C Lei
- College of Veterinary Medicine, Jilin University, Changchun, Jiling, China
| | - Z S Liu
- College of Veterinary Medicine, Jilin University, Changchun, Jiling, China
| | - X-C Zhang
- College of Veterinary Medicine, Jilin University, Changchun, Jiling, China
| | - M Y Liu
- College of Veterinary Medicine, Jilin University, Changchun, Jiling, China
| | - J C Cui
- College of Life Science, Dalian Minzu University, Dalian, Liaoning, China
| | - A Nakane
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| |
Collapse
|
14
|
Ono HK, Hirose S, Naito I, Sato'o Y, Asano K, Hu DL, Omoe K, Nakane A. The emetic activity of staphylococcal enterotoxins, SEK, SEL, SEM, SEN and SEO in a small emetic animal model, the house musk shrew. Microbiol Immunol 2017; 61:12-16. [PMID: 28042656 DOI: 10.1111/1348-0421.12460] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 12/18/2016] [Accepted: 12/20/2016] [Indexed: 11/30/2022]
Abstract
Staphylococcal enterotoxins (SEs) produced by Staphylococcus aureus are the most recognizable causative agents of emetic food poisoning in humans. New types of SEs and SE-like (SEl) toxins have been reported. Several epidemiological investigations have shown that the SEs and SEl genes, particularly, SEK, SEL, SEM, SEN and SEO genes, are frequently detected in strains isolated from patients with food poisoning. The purpose of the present study was to evaluate the emetic activity of recently identified SEs using a small emetic animal model, the house musk shrew. The emetic activity of these SEs in house musk shrews was evaluated by intraperitoneal administration and emetic responses, including the number of shrews that vomited, emetic frequency and latency of vomiting were documented. It was found that SEs induce emetic responses in these animals. This is the first time to demonstrate that SEK, SEL, SEM, SEN and SEO possess emetic activity in the house musk shrew.
Collapse
Affiliation(s)
- Hisaya K Ono
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562.,Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, 35-1 Higashi-23-ban-cho, Towada, Aomori 034-8628
| | - Shouhei Hirose
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562
| | - Ikunori Naito
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550
| | - Yusuke Sato'o
- Division of Bacteriology, Department of Infection and Immunity, School of Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
| | - Krisana Asano
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562
| | - Dong-Liang Hu
- Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, 35-1 Higashi-23-ban-cho, Towada, Aomori 034-8628
| | - Katsuhiko Omoe
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, Iwate 020-8550
| | - Akio Nakane
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562
| |
Collapse
|
15
|
Enterotoxin Gene Cluster-Encoded SEI and SElN from Staphylococcus aureus Isolates are Crucial for the Induction of Human Blood Cell Proliferation and Pathogenicity in Rabbits. Toxins (Basel) 2016; 8:toxins8110314. [PMID: 27801832 PMCID: PMC5127111 DOI: 10.3390/toxins8110314] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 10/20/2016] [Accepted: 10/25/2016] [Indexed: 11/17/2022] Open
Abstract
Among the toxin family of bacterial superantigens, the six members of the enterotoxin gene cluster (egc) seem to have unusual characteristics. They are present in the majority of Staphylococcus aureus strains, but their role in disease remains uncertain. We assessed secretion levels, immunogenicity, and toxicity of native and recombinant egc proteins. After having developed enzyme-linked immunosorbent assays, we found different quantities of egc proteins secreted by bacterial isolates. Supernatants induced proliferation of human peripheral blood mononuclear cells. However, purified recombinant egc proteins were shown to have differing superantigenicity potentials. Immunization with identical amounts of all members of egc, and the prominent toxic agent SEB, resulted in neutralizing antisera. Two egc proteins, SEI and SElN, were found to play a predominant role within the cluster. Both displayed the highest potential to activate blood cells, and were essential to be neutralized in supernatants. The application of a supernatant of a strain bearing only egc was sufficient for a lethal outcome in a rabbit model. Again, neutralization of SEI and SElN led to the survival of all tested animals. Finally, nanogram amounts of purified rSEI and rSElN led to lethality in vivo, pointing out the importance of both as virulence determinants among egc superantigens.
Collapse
|
16
|
Park C, Seong CN. The Correlation between Toxin Genotype and Antibiotic Resistance in Methicillin ResistantStaphylococcus aureusIsolated from Clinical Specimen of Intensive Care Unit. KOREAN JOURNAL OF CLINICAL LABORATORY SCIENCE 2016. [DOI: 10.15324/kjcls.2016.48.3.202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- Chul Park
- Department of Clinical Laboratory Science, Gwangyang Health Science University, Gwangyang 57764, Korea
| | - Chi Nam Seong
- Department of Biology, College of Life Science and Natural Resources, Sunchon National University, Suncheon 57922, Korea
| |
Collapse
|
17
|
Correlación entre la detección de superantígenos y resistencia a oxacilina en aislamientos hospitalarios de Staphylococcus aureus. INFECTIO 2015. [DOI: 10.1016/j.infect.2015.02.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
18
|
Li Y, Zhao R, Zhang X, Han Q, Qian X, Gu G, Shi J, Xu J. Prevalence of Enterotoxin Genes and spa Genotypes of Methicillin-resistant Staphylococcus aureus from a Tertiary Care Hospital in China. J Clin Diagn Res 2015; 9:DC11-4. [PMID: 26155477 DOI: 10.7860/jcdr/2015/12090.5990] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 04/02/2015] [Indexed: 11/24/2022]
Abstract
OBJECTIVES Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen that causes a variety of infections. MRSA has evolved resistance to multiple antibiotics. Genetic background and virulence differs in different geographic regions. The present study was aimed to investigate the prevalence of enterotoxin genes and spa genotypes of hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) isolated from a tertiary care hospital of Jiangsu province, China. MATERIALS AND METHODS HA-MRSA isolates from August 2013 to April 2014 at a tertiary care hospital of China were collected. We investigated antimicrobial pattern, spa types, SCCmec types and the presence of 14 virulence genes. RESULTS Eighty HA-MRSA isolates were collected. Results from SCCmec typing revealed that 73.8% were type II; 13.8% were type III; 12.5% were type V. There were 19 different spa types. Spa type t2460 was the most common (35.0%), followed by t002 (11.3%). CC5 was the predominant MLST CCs type (50%). The most frequent toxin genes were sea, seb, sed, sel, sen and seo (100.0%). None of the investigated isolates carried the sec or tst. CONCLUSION Genotypic and virulence evaluation of the isolated HA-MRSA revealed that the isolates with CC5 and SCCmec II were the predominant type and highly homological. The virulence profiles mainly existed in the genes of sea, seb, sed, sel, sen, seo and ser. The prevalence of t2460 was an outbreak and the predominant spa type.
Collapse
Affiliation(s)
- Yanmeng Li
- Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China
| | - Ruike Zhao
- Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China
| | - Xianfeng Zhang
- Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China
| | - Qingzhen Han
- Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China
| | - Xuefeng Qian
- Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China
| | - Guohao Gu
- Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou, P.R. of China
| | - Jinfang Shi
- Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou,P.R. of China
| | - Jie Xu
- Faculty, Department of Clinical Laboratory, the First Affiliated Hospital of Soochow University , Suzhou,P.R. of China
| |
Collapse
|
19
|
Narita K, Hu DL, Asano K, Nakane A. Vaccination with non-toxic mutant toxic shock syndrome toxin-1 induces IL-17-dependent protection against Staphylococcus aureus infection. Pathog Dis 2015; 73:ftv023. [PMID: 25857736 DOI: 10.1093/femspd/ftv023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2015] [Indexed: 12/24/2022] Open
Abstract
Toxic shock syndrome toxin-1 (TSST-1) is one of superantigens produced by Staphylococcus aureus. We have previously demonstrated that vaccination with non-toxic mutant TSST-1 (mTSST-1) develops host protection to lethal S. aureus infection in mice. However, the detailed mechanism underlying this protection is necessary to elucidate because the passive transfer of antibodies against TSST-1 fails to provide complete protection against S. aureus infection. In this study, the results showed that interleukin-17A (IL-17A)-producing cells were increased in the spleen cells of mTSST-1-vaccinated mice. The main source of IL-17A in mTSST-1-vaccinated mice was T-helper 17 (Th17) cells. The protective effect of vaccination was induced when the vaccinated wild type but not IL-17A-deficient mice were challenged with S. aureus. Gene expression of chemokines, CCL2 and CXCL1, and infiltration of neutrophils and macrophages were increased in spleens and livers of vaccinated mice after infection. The IL-17A-dependent immune response was TSST-1 specific because TSST-1-deficient S. aureus failed to induce the response. The present study suggests that mTSST-1 vaccination is able to provide the IL-17A-dependent host defense against S. aureus infection which promotes chemokine-mediated infiltration of phagocytes into the infectious foci.
Collapse
Affiliation(s)
- Kouji Narita
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan Institute for Animal Experimentation, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan
| | - Dong-Liang Hu
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan Laboratory of Zoonoses, Kitasato University School of Veterinary Medicine, Towada, Aomori 034-8628, Japan
| | - Krisana Asano
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan
| | - Akio Nakane
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori 036-8562, Japan
| |
Collapse
|
20
|
Superantigens in Staphylococcus aureus isolated from prosthetic joint infection. Diagn Microbiol Infect Dis 2014; 81:201-7. [PMID: 25619753 DOI: 10.1016/j.diagmicrobio.2014.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 11/03/2014] [Accepted: 11/14/2014] [Indexed: 10/24/2022]
Abstract
Staphylococcus aureus is a common cause of prosthetic joint infection (PJI). The prevalence of superantigens (SAgs) among PJI-associated S. aureus is unknown. Eighty-four S. aureus isolates associated with PJI isolated between 1999 and 2006 were studied. SAg genes, sea, seb, sec, sed, see, seg, seh, sei, and tst, were assayed by PCR. Seventy-eight (92.9%) isolates carried at least 1 SAg gene studied, with 61 (72.6%) harboring more than 1. seg was most commonly (70.2%), and seh was least frequently (4.8%) detected. tst-positive isolates were associated with early infection and increased erythrocyte sedimentation rate at diagnosis (P=0.006 and P=0.021, respectively). seg and sei were associated with methicillin resistance (P=0.008 and P=0.002, respectively). A majority of PJI-associated isolates studied produced biologically active SAgs in both planktonic and biofilm growth modes. SAg genes are prevalent in S. aureus causing PJI.
Collapse
|
21
|
Fernández L, Arroyo R, Espinosa I, Marín M, Jiménez E, Rodríguez JM. Probiotics for human lactational mastitis. Benef Microbes 2014; 5:169-83. [PMID: 24463206 DOI: 10.3920/bm2013.0036] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The use of culture-dependent and -independent techniques to study the human milk microbiota and microbiome has revealed a complex ecosystem with a much greater diversity than previously anticipated. The potential role of the milk microbiome appears to have implications not only for short- and long-term infant health but also for mammary health. In fact, mammary disbiosis, which may be triggered by a variety of host, microbial and medical factors, often leads to acute, subacute or subclinical mastitis, a condition that represents the first medical cause for undesired weaning. Multiresistance to antibiotics, together with formation of biofilms and mechanisms for evasion of the host immune response, is a common feature among the bacterial agents involved. This explains why this condition uses to be elusive to antibiotic therapy and why the development of new strategies for mastitis management based on probiotics is particularly appealing. In fact, selected lactobacilli strains isolated from breast milk have already shown a high efficacy for treatment.
Collapse
Affiliation(s)
- L Fernández
- Department of Nutrition, Food Science and Food Technology, Complutense University of Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain Probisearch SL, C/ Santiago Grisolía 2, 28760 Tres Cantos, Spain
| | - R Arroyo
- Department of Nutrition, Food Science and Food Technology, Complutense University of Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - I Espinosa
- Probisearch SL, C/ Santiago Grisolía 2, 28760 Tres Cantos, Spain
| | - M Marín
- Department of Nutrition, Food Science and Food Technology, Complutense University of Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - E Jiménez
- Department of Nutrition, Food Science and Food Technology, Complutense University of Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain
| | - J M Rodríguez
- Department of Nutrition, Food Science and Food Technology, Complutense University of Madrid, Avda. Puerta de Hierro s/n, 28040 Madrid, Spain Probisearch SL, C/ Santiago Grisolía 2, 28760 Tres Cantos, Spain
| |
Collapse
|
22
|
Nakane A. [Host responses to bacterial infections]. Nihon Saikingaku Zasshi 2014; 69:479-89. [PMID: 25186639 DOI: 10.3412/jsb.69.479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Pathogenic bacteria and host defense system have been evolved by their offense and defense. In vivo research is crucial for elucidation of interactions between them. I have investigated their offence and defense by various standpoints using mouse models of Listeria monocytogenes and Staphylococcus aureus infections. Herein, the results of my research including the roles of endogenous cytokines in host defense, the attenuation of host defense mechanism in obesity and diabetes, the development of vaccines against S. aureus infection by staphylococcal enterotoxin (SE) family molecules, and the emesis-inducing mechanism of SEA are described.
Collapse
Affiliation(s)
- Akio Nakane
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine
| |
Collapse
|
23
|
Tilahun AY, Chowdhary VR, David CS, Rajagopalan G. Systemic inflammatory response elicited by superantigen destabilizes T regulatory cells, rendering them ineffective during toxic shock syndrome. THE JOURNAL OF IMMUNOLOGY 2014; 193:2919-30. [PMID: 25092888 DOI: 10.4049/jimmunol.1400980] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Life-threatening infections caused by Staphylococcus aureus, particularly the community-acquired methicillin-resistant strains of S. aureus, continue to pose serious problems. Greater virulence and increased pathogenicity of certain S. aureus strains are attributed to higher prevalence of exotoxins. Of these exotoxins, the superantigens (SAg) are likely most pathogenic because of their ability to rapidly and robustly activate the T cells even in extremely small quantities. Therefore, countering SAg-mediated T cell activation using T regulatory cells (Tregs) might be beneficial in diseases such as toxic shock syndrome (TSS). As the normal numbers of endogenous Tregs in a typical host are insufficient, we hypothesized that increasing the Treg numbers by administration of IL-2/anti-IL-2 Ab immune complexes (IL2C) or by adoptive transfer of ex vivo expanded Tregs might be more effective in countering SAg-mediated immune activation. HLA-DR3 transgenic mice that closely recapitulate human TSS were treated with IL2C to increase endogenous Tregs or received ex vivo expanded Tregs. Subsequently, they were challenged with SAg to induce TSS. Analyses of various parameters reflective of TSS (serum cytokine/chemokine levels, multiple organ pathology, and SAg-induced peripheral T cell expansion) indicated that increasing the Tregs failed to mitigate TSS. On the contrary, serum IFN-γ levels were increased in IL2C-treated mice. Exploration into the reasons behind the lack of protective effect of Tregs revealed IL-17 and IFN-γ-dependent loss of Tregs during TSS. In addition, significant upregulation of glucocorticoid-induced TNFR family-related receptor on conventional T cells during TSS could render them resistant to Treg-mediated suppression, contributing to failure of Treg-mediated immune regulation.
Collapse
Affiliation(s)
| | - Vaidehi R Chowdhary
- Division of Rheumatology, Department of Medicine, Mayo Clinic, Rochester, MN 55905; and
| | - Chella S David
- Department of Immunology, Mayo Clinic, Rochester, MN 55905
| | - Govindarajan Rajagopalan
- Department of Immunology, Mayo Clinic, Rochester, MN 55905; Division of Infectious Diseases, Mayo Clinic, Rochester, MN 55905
| |
Collapse
|
24
|
Sharma P, Wang N, Kranz DM. Soluble T cell receptor Vβ domains engineered for high-affinity binding to staphylococcal or streptococcal superantigens. Toxins (Basel) 2014; 6:556-74. [PMID: 24476714 PMCID: PMC3942751 DOI: 10.3390/toxins6020556] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 01/21/2014] [Accepted: 01/22/2014] [Indexed: 11/29/2022] Open
Abstract
Staphylococcus aureus and group A Streptococcus secrete a collection of toxins called superantigens (SAgs), so-called because they stimulate a large fraction of an individual’s T cells. One consequence of this hyperactivity is massive cytokine release leading to severe tissue inflammation and, in some cases, systemic organ failure and death. The molecular basis of action involves the binding of the SAg to both a T cell receptor (TCR) on a T cell and a class II product of the major histocompatibility complex (MHC) on an antigen presenting cell. This cross-linking leads to aggregation of the TCR complex and signaling. A common feature of SAgs is that they bind with relatively low affinity to the variable region (V) of the beta chain of the TCR. Despite this low affinity binding, SAgs are very potent, as each T cell requires only a small fraction of their receptors to be bound in order to trigger cytokine release. To develop high-affinity agents that could neutralize the activity of SAgs, and facilitate the development of detection assays, soluble forms of the Vβ regions have been engineered to affinities that are up to 3 million-fold higher for the SAg. Over the past decade, six different Vβ regions against SAgs from S. aureus (SEA, SEB, SEC3, TSST-1) or S. pyogenes (SpeA and SpeC) have been engineered for high-affinity using yeast display and directed evolution. Here we review the engineering of these high-affinity Vβ proteins, structural features of the six different SAgs and the Vβ proteins, and the specific properties of the engineered Vβ regions that confer high-affinity and specificity for their SAg ligands.
Collapse
Affiliation(s)
- Preeti Sharma
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA.
| | - Ningyan Wang
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA.
| | - David M Kranz
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA.
| |
Collapse
|
25
|
Sato'o Y, Omoe K, Ono HK, Nakane A, Hu DL. A novel comprehensive analysis method for Staphylococcus aureus pathogenicity islands. Microbiol Immunol 2013; 57:91-9. [PMID: 23252668 DOI: 10.1111/1348-0421.12007] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 10/31/2012] [Accepted: 11/12/2012] [Indexed: 11/30/2022]
Abstract
Staphylococcus aureus pathogenicity islands (SaPIs) form a growing family of mobile genetic elements (MGEs) in Staphylococci. Horizontal genetic transfer by MGEs plays an important role in the evolution of S. aureus. Several SaPIs carry staphylococcal enterotoxin and SE-like toxin genes. To comprehensively investigate the diversity of SaPIs, a series of primers corresponding to sequences flanking six SaPI insertion sites in S. aureus genome were designed and a long and accurate (LA)-PCR analysis method established. LA-PCR products of 13-17 kbp were observed in strains with seb, selk or selq genes. Restriction fragment length polymorphism (RFLP) analysis showed that the products have different RFLP characteristics than do previously described SaPIs; they were therefore predicted to include new SaPIs. Nucleotide sequencing analysis revealed seven novel SaPIs: seb-harboring SaPIivm10, SaPishikawa11, SaPIivm60, SaPIno10 and SaPIhirosaki4, selk and selq-harboring SaPIj11 and non-superantigen-harboring SaPIhhms2. These SaPIs have mosaic structures containing components of known SaPIs and other unknown genes. Strains carrying different SaPIs were found to have significantly different production of superantigen toxins. The present results show that the LA-PCR approach can comprehensively identify SaPI diversity and is useful for investigating the evolution of S. aureus pathogenicity.
Collapse
Affiliation(s)
- Yusuke Sato'o
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, Morioka, Iwate, Japan
| | | | | | | | | |
Collapse
|
26
|
Characterization of colonizing Staphylococcus aureus isolated from surgical wards' patients in a Nigerian university hospital. PLoS One 2013; 8:e68721. [PMID: 23935883 PMCID: PMC3720814 DOI: 10.1371/journal.pone.0068721] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 06/01/2013] [Indexed: 12/28/2022] Open
Abstract
In contrast to developed countries, only limited data on the prevalence, resistance and clonal structure of Staphylococcus aureus are available for African countries. Since S. aureus carriage is a risk factor for postoperative wound infection, patients who had been hospitalized in surgical wards in a Nigerian University Teaching Hospital were screened for S. aureus carriage. All S. aureus isolates were genotyped (spa, agr) and assigned to multilocus sequence types (MLST). Species affiliation, methicillin-resistance, and the possession of pyrogenic toxin superantigens (PTSAg), exfoliative toxins (ETs) and Panton-Valentine Leukocidin (PVL) were analyzed. Of 192 patients screened, the S. aureus carrier rate was 31.8 % (n = 61). Of these isolates, 7 (11.5%) were methicillin-resistant (MRSA). The isolates comprised 24 spa types. The most frequent spa types were t064, t084, t311, and t1931, while the most prevalent MLST clonal complexes were CC5 and CC15. The most frequent PTSAg genes detected were seg/sei (41.0%) followed by seb (29.5%), sea (19.7%), seh (14.7%) and sec (11.5). The difference between the possession of classical and newly described PTSAg genes was not significant (63.9% versus 59.0% respectively; P = 0.602). PVL encoding genes were found in 39.3% isolates. All MRSA isolates were PVL negative, SCCmec types I and VI in MLST CC 5 and CC 30, respectively. Typing of the accessory gene regulator (agr) showed the following distribution: agr group 1 (n = 20), group II (n = 17), group III (n = 14) and group IV (n = 10). Compared to European data, enterotoxin gene seb and PVL-encoding genes were more prevalent in Nigerian methicillin-susceptible S. aureus isolates, which may therefore act as potential reservoir for PVL and PTSAg genes.
Collapse
|
27
|
Lim KT, Yeo CC, Suhaili Z, Thong KL. Comparison of methicillin-resistant and methicillin-sensitive Staphylococcus aureus strains isolated from a tertiary hospital in Terengganu, Malaysia. Jpn J Infect Dis 2013. [PMID: 23183202 DOI: 10.7883/yoken.65.502] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Staphylococcus aureus is a persistent human pathogen responsible for a variety of infections ranging from soft-tissue infections to bacteremia. The objective of this study was to determine genetic relatedness between methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) strains. We isolated 35 MRSA and 21 MSSA strains from sporadic cases at the main tertiary hospital in Terengganu, Malaysia, screening them for the presence of virulence genes. Their genetic relatedness was determined by accessory gene regulator (agr) types, PCR-restriction fragment length polymorphism (RFLP) of the coa gene, pulsed-field gel electrophoresis (PFGE), S. aureus protein A (spa), and multilocus-sequence typing (MLST). We found that 57% of MRSA and 43% of MSSA strains harbored enterotoxin genes. The majority (87.5%) of the strains were agr type I. PCR-RFLP and PFGE genotyping of the coa gene revealed that MRSA strains were genetically related, whereas MSSA strains had higher heterogeneity. The combined genotype, MLST-spa type ST239-t037, was shared among MRSA and MSSA strains, indicating that MRSA strains could have evolved from MSSA strains. Two combined MLST-spa types were present in MRSA strains, whereas 7 different MLST-spa types were detected in MSSA strains, including 2 combined types (ST779-t878 and ST1179-t267) that have not been reported in Malaysia. In conclusion, enterotoxin genes were more prevalent in MRSA than in MSSA strains in the Terengganu hospital. The MSSA strains were genetically more diverse than the MRSA strains.
Collapse
Affiliation(s)
- King Ting Lim
- Microbiology Division, Institute of Biological Science, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
| | | | | | | |
Collapse
|
28
|
Osanai A, Hu DL, Nakane A. Caenorhabditis elegansavoids staphylococcal superantigenic toxins via 5-hydroxytryptamine-dependent pathway. Can J Microbiol 2012; 58:1268-77. [DOI: 10.1139/w2012-107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Avoidance behavior of Caenorhabditis elegans, a nematode, towards Staphylococcus aureus, a pathogenic bacterium, was studied. Caenorhabditis elegans avoided S. aureus cultures and also their culture supernatants, suggesting that secretory molecules are involved in the repellent activity. We demonstrated that toxic shock syndrome toxin 1 (TSST-1) and staphylococcal enterotoxin C (SEC), the superantigenic toxins produced by S. aureus, are responsible for the nematode avoidance. By using TSST-1 and SEC mutants, the results indicated that the repellent activity of these toxins is independent of their superantigenic activity. The TSST-1 and SEC were found to locate at chemosensory neurons that are responsible for the recognition of repellents and avoidance of pathogenic bacteria. When mutants of C. elegans deficient in Toll/interleukin-1 receptor (TIR-1) and 5-hydroxytryptamine (5-HT) biosynthesis were used, avoidance behavior was attenuated. In the 5-HT biosynthesis deficient mutant nematodes, the avoidance activity was recovered when exogenous 5-HT was added. tph-1 expression and 5-HT production were upregulated when the nematodes were treated with TSST-1 or SEC. These results suggest that C. elegans avoids S. aureus by recognizing secretory molecules including TSST-1 and SEC and this avoidance is dependent on TIR and production of 5-HT.
Collapse
Affiliation(s)
- Arihiro Osanai
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, 036-8562, Japan
| | - Dong-Liang Hu
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, 036-8562, Japan
| | - Akio Nakane
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, 036-8562, Japan
| |
Collapse
|
29
|
Argudín MA, Argumosa V, Mendoza MC, Guerra B, Rodicio MR. Population structure and exotoxin gene content of methicillin-susceptible Staphylococcus aureus from Spanish healthy carriers. Microb Pathog 2012; 54:26-33. [PMID: 22982529 DOI: 10.1016/j.micpath.2012.09.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 09/01/2012] [Accepted: 09/06/2012] [Indexed: 10/27/2022]
Abstract
The population structure of 111 methicillin-susceptible Staphylococcus aureus (MSSA), recovered in Spain from healthy and risk-free carriers was investigated using pulsed-field gel electrophoresis (PFGE), spa (staphylococcal protein A) typing, multi locus sequence typing (MLST) and the accessory gene regulator (agr). Results from the different techniques were highly concordant, and revealed twelve clonal complexes (CCs): CC30 (27%), CC5 (18.9%), CC45 (16.2%), CC15 (11.7%), CC25 (8.1%), CC1, CC9 (3.6% each), CC59, CC97 and CC121 (2.7% each), CC72 (1.8%) and CC8 (0.9%). Isolates with genetic backgrounds of hospital-acquired MSSA were detected and, consistent with the ability of diverse MSSA to act as recipients of the SCCmec cassette, a MSSA isolate from a healthy carrier shared the ST, spa-type and agr-type of a MRSA clone recovered in a hospital of the same region. All except two fragments of the PGFE-profiles of these isolates were identical, and the differential fragment of the MRSA carried mecA. Analyses of the exotoxin gene content of the nasal isolates revealed an increase in the number of exotoxin genes over time. This, together with the detection of lukPV and the high frequency of tst, exfoliatin and enterotoxin genes, is worrisome and requires further surveillance.
Collapse
Affiliation(s)
- M Angeles Argudín
- Department of Functional Biology (Microbiology Section), Faculty of Medicine, University of Oviedo, Julián Clavería 6, 33006 Oviedo, Spain
| | | | | | | | | |
Collapse
|
30
|
Lim KT, Hanifah YA, Yusof MYM, Thong KL. Characterisation of the Virulence Factors and Genetic Types of Methicillin Susceptible Staphylococcus aureus from Patients and Healthy Individuals. Indian J Microbiol 2012; 52:593-600. [PMID: 24293716 DOI: 10.1007/s12088-012-0286-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 06/04/2012] [Indexed: 11/29/2022] Open
Abstract
Methicillin sensitive Staphylococcus aureus is an important bacterial pathogen associated with hospital- and community-acquired infections leading to endocarditis, skin tissue infection and pneumonia. The objective of this study was to determine both the genetic characteristics of methicillin-sensitive S. aureus (MSSA) strains, and the occurrence of virulence factors produced by S. aureus strains isolated from UMMC and healthy students in the University from year 2009. Out of 429 nasal swab samples, 67 were MSSA. The prevalence of 21 different virulence genes among 67 Malaysian clinical and community MSSA strains was determined by PCR, and their genetic features were assessed by PCR-RFLP of coa gene, agr types, spa typing and PFGE. The five predominant virulence genes were ica (79 %), efb and fnbA (61 % each), sdrE (57 %) and hlg (45 %). Toxin genes (enterotoxin, etd and pvl) were significantly more common (P < 0.05) in clinical strains compared to community strains. Three agr genotypes were observed: agr type I (45 %), agr type III (25 %) and agr type II (19 %). All 67 MSSA strains were distinguished into 26 profiles by PCR-RFLP of coa, 55 pulsotypes and 21 spa types. Four novel spa types (t7312, t7581, t7582 and t7583) were observed. In conclusion, different virulence profiles were observed in MSSA strains in Malaysia where toxin genes were more prevalent among clinical strains. No correlation between DNA profiles (coa-RFLP, PFGE and spa) and virulotypes was observed. The Malaysian MSSA strains from clinical and community sources were genetically diverse and heterogeneous.
Collapse
Affiliation(s)
- King-Ting Lim
- Institute of Biological Science, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia ; Biomedical Science and Molecular Microbiology Laboratory, Institute of Graduate Studies, University of Malaya, Kuala Lumpur, Malaysia
| | | | | | | |
Collapse
|
31
|
Staphylococcal enterotoxin A has potent superantigenic and emetic activities but not diarrheagenic activity. Int J Med Microbiol 2012; 302:88-95. [PMID: 22424598 DOI: 10.1016/j.ijmm.2012.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 01/10/2012] [Accepted: 01/15/2012] [Indexed: 11/21/2022] Open
Abstract
Staphylococcal enterotoxins (SEs) produced by Staphylococcus aureus are pyrogenic superantigenic toxins that are involved in human diseases including food poisoning and toxic shock syndrome. Although the superantigenic activity of SEs has been well characterized, its role and mechanism in clinical symptoms of food poisoning remain poorly understood. In this study, house musk shrews (Suncus murinus), a small emetic animal model, were used to study the role of SEs in clinical manifestations of food poisoning. Administration of SEA induced a potent emetic response in vivo and showed significant superantigenic activity in vitro in house musk shrews. However, SEA revealed no diarrheagenic activity. SEA directly injected into the intestinal loops of house musk shrews failed to induce fluid exudation and consequent dilation of the intestinal segments. Rabbit intestinal loop experiments were further carried out to confirm the results and also showed that SEA induced no fluid exudation and consequent dilation. Furthermore, the SEA-producing S. aureus also failed to induce fluid exudation in the administered loops of these animal models. These results indicate that SEA has potent superantigenic and emetic activities, but does not have a diarrheagenic activity.
Collapse
|
32
|
Kim TS, Kim MJ, Kim SH, Kee HY, Seo JJ, Kim ES, Moon YU, Ryu PY, Ha DR. Profile of Antimicrobial Resistance of Staphylococcus aureusand Molecular Epidemiologic Characterization of Methicillin-resistant Staphylococcus aureus(MRSA) Isolated from Hands of People Using Multitude Facilities. Infect Chemother 2012. [DOI: 10.3947/ic.2012.44.4.289] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Tae Sun Kim
- Health & Environment Institute of Gwangju, Health Research Department, Microbioloy Division, Gwangju, Korea
| | - Min Ji Kim
- Health & Environment Institute of Gwangju, Health Research Department, Microbioloy Division, Gwangju, Korea
| | - Sun Hee Kim
- Health & Environment Institute of Gwangju, Health Research Department, Microbioloy Division, Gwangju, Korea
| | - Hye-young Kee
- Health & Environment Institute of Gwangju, Health Research Department, Microbioloy Division, Gwangju, Korea
| | - Jin-jong Seo
- Health & Environment Institute of Gwangju, Health Research Department, Microbioloy Division, Gwangju, Korea
| | - Eun-Sun Kim
- Health & Environment Institute of Gwangju, Health Research Department, Microbioloy Division, Gwangju, Korea
| | - Yong-Un Moon
- Health & Environment Institute of Gwangju, Health Research Department, Microbioloy Division, Gwangju, Korea
| | - Puil Youl Ryu
- Department of Microbiology, Chonnam National University Medical School, Gwangju, Korea
| | - Dong-Ryong Ha
- Health & Environment Institute of Gwangju, Health Research Department, Microbioloy Division, Gwangju, Korea
| |
Collapse
|
33
|
Argudín MÁ, Mendoza MC, Vázquez F, Rodicio MR. Exotoxin gene backgrounds in bloodstream and wound Staphylococcus aureus isolates from geriatric patients attending a long-term care Spanish hospital. J Med Microbiol 2011; 60:1605-1612. [DOI: 10.1099/jmm.0.034611-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- M. Ángeles Argudín
- Department of Functional Biology, Laboratory of Microbiology, University of Oviedo, Oviedo, Spain
| | - M. Carmen Mendoza
- Department of Functional Biology, Laboratory of Microbiology, University of Oviedo, Oviedo, Spain
| | - Fernando Vázquez
- Monte Naranco Hospital, Oviedo, Spain
- Department of Functional Biology, Laboratory of Microbiology, University of Oviedo, Oviedo, Spain
| | - M. Rosario Rodicio
- Department of Functional Biology, Laboratory of Microbiology, University of Oviedo, Oviedo, Spain
| |
Collapse
|
34
|
Takata T, Miyazaki M, Li H, Healy M, Frye S, Tanaka K, Hara S, Kamimura H, Yoshimura H, Matsunaga A, Ohta D, Ishikura H, Tamura K, Tang YW. Methicillin-resistant Staphylococcus aureus bloodstream infections in a Japanese University Hospital between 1987 and 2004. J Infect Chemother 2011; 18:199-206. [PMID: 22009526 DOI: 10.1007/s10156-011-0313-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 09/20/2011] [Indexed: 10/16/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections have been the most common cause of nosocomial infections in Japan, but their genetic characteristics related to bloodstream infections have not been well studied. The aim of this study was to investigate a comprehensive molecular characterization of MRSA blood isolates during the historical 18-year study period between 1987 and 2004 in a tertiary care university hospital. A total of 137 MRSA isolates recovered from the blood of inpatients at Fukuoka University Hospital were analyzed. Clinical information and antimicrobial susceptibility profiles were reviewed, and staphylococcal chromosomal cassette mec (SCCmec), accessory gene regulator (agr), and a battery of bacterial genes were tested by PCR-based assays. The relatedness of these isolates was determined by the repetitive sequence-based PCR (rep-PCR) and pulsed-field gel electrophoresis (PFGE). Although low numbers of agr type III/SCCmec type IV isolates circulated between 1987 and 1992, agr type II/SCCmec type II isolates started circulating in 1993 and were responsible for the increased MRSA isolates until 2004. The rep-PCR and PFGE identified 104 epidemic and 33 sporadic isolates. Among the 104 epidemic isolates, six major rep-PCR/PFGE types were identified, which occupied 67.3% of epidemic isolates. The SCCmec type II and agr type II isolates were observed in significantly higher proportion in epidemic isolates than in sporadic isolates (P = 0.0318, P = 0.0123, respectively). In contrast, SCCmec type IV strains were observed in significantly higher proportion in sporadic isolates than in epidemic isolates (P = 0.0494). Although isolates with sec were detected in higher rates in epidemic isolates (P = 0.0397), seh was detected in higher rates in sporadic isolates (P = 0.0350). Multivariate logistic regression analysis with forward stepping revealed that SCCmec type II was independently associated with epidemic isolates (P = 0.0067; odds ratio, 1.75; 95% confidence interval, 1.17-2.64). These data indicated that SCCmec type II MRSA isolates were responsible for the increased MRSA bloodstream infections for inpatients during the 18-year study period in the hospital.
Collapse
Affiliation(s)
- Tohru Takata
- Department of Oncology, Hematology, and Infectious Diseases, Fukuoka University School of Medicine, Fukuoka, Japan.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Dearborn AD, Spilman MS, Damle PK, Chang JR, Monroe EB, Saad JS, Christie GE, Dokland T. The Staphylococcus aureus pathogenicity island 1 protein gp6 functions as an internal scaffold during capsid size determination. J Mol Biol 2011; 412:710-22. [PMID: 21821042 DOI: 10.1016/j.jmb.2011.07.036] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 07/18/2011] [Accepted: 07/18/2011] [Indexed: 10/17/2022]
Abstract
Staphylococcus aureus pathogenicity island 1 (SaPI1) is a mobile genetic element that carries genes for several superantigen toxins. SaPI1 is normally stably integrated into the host genome but can become mobilized by "helper" bacteriophage 80α, leading to the packaging of SaPI1 genomes into phage-like transducing particles that are composed of structural proteins supplied by the helper phage but having smaller capsids. We show that the SaPI1-encoded protein gp6 is necessary for efficient formation of small capsids. The NMR structure of gp6 reveals a dimeric protein with a helix-loop-helix motif similar to that of bacteriophage scaffolding proteins. The gp6 dimer matches internal densities that bridge capsid subunits in cryo-electron microscopy reconstructions of SaPI1 procapsids, suggesting that gp6 acts as an internal scaffolding protein in capsid size determination.
Collapse
Affiliation(s)
- Altaira D Dearborn
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Kim T, Yi J, Hong KH, Park JS, Kim EC. Distribution of virulence genes in spa types of methicillin-resistant Staphylococcus aureus isolated from patients in intensive care units. Korean J Lab Med 2011; 31:30-6. [PMID: 21239868 PMCID: PMC3111032 DOI: 10.3343/kjlm.2011.31.1.30] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Various virulence factors and superantigens are encoded by mobile genetic elements. The relationship between clonal background and virulence factors differs in different geographic regions. We compared the distribution and relationship of spa types and virulence genes among methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from a tertiary hospital in 2000-01 and 2007-08. METHODS In 2000-01 and 2007-08, 94 MRSA strains were collected from 3 intensive care units at a Korean tertiary hospital. We performed spa typing and multiplex PCR for 19 superantigen genes. RESULTS Relatively frequent spa types were t037 (40.5%), t002, t601, and t2138 in 2000-01, and t2460 (43.9%), t002, t037, t601, t324, and t2139 in 2007-08. We identified 4 novel spa types, 2 of which were designated as t5076 and t5079. Superantigen profiles were closely linked to spa types. For example, sea, sek, and seq superantigen genes were mainly detected in t037 strains. CONCLUSIONS Major spa types differed depending on study periods, and the distribution of superantigen genes correlated with spa type.
Collapse
Affiliation(s)
- Taeksoo Kim
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
| | | | | | | | | |
Collapse
|
37
|
Li SJ, Hu DL, Maina E, Shinagawa K, Omoe K, Nakane A. Superantigenic activity of toxic shock syndrome toxin-1 is resistant to heating and digestive enzymes. J Appl Microbiol 2011; 110:729-36. [DOI: 10.1111/j.1365-2672.2010.04927.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
38
|
Hwang SY, Park YK, Koo HC, Park YH. spa typing and enterotoxin gene profile of Staphylococcus aureus isolated from bovine raw milk in Korea. J Vet Sci 2011; 11:125-31. [PMID: 20458153 PMCID: PMC2873812 DOI: 10.4142/jvs.2010.11.2.125] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus is a major etiological pathogen of bovine mastitis, which triggers significant economic losses in dairy herds worldwide. In this study, S. aureus strains isolated from the milk of cows suffering from mastitis in Korea were investigated by spa typing and staphylococcal enterotoxin (SE) gene profiling. Forty-four S. aureus strains were isolated from 26 farms in five provinces. All isolates grouped into five clusters and two singletons based on 14 spa types. Cluster 1 and 2 isolates comprised 38.6% and 36.4% of total isolates, respectively, which were distributed in more than four provinces. SE and SE-like toxin genes were detected in 34 (77.3%) isolates and the most frequently detected SE gene profile was seg, sei, selm, seln, and selo genes (16 isolates, 36.3%), which was comparable to one of the genomic islands, Type I nuSabeta. This is a first report of spa types and the prevalence of the recently described SE and SE-like toxin genes among S. aureus isolates from bovine raw milk in Korea. Two predominant spa groups were distributed widely and recently described SE and SE-like toxin genes were detected frequently.
Collapse
Affiliation(s)
- Sun Young Hwang
- Department of Microbiology, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Seoul 151-742, Korea
| | | | | | | |
Collapse
|
39
|
Hu DL, Maina EK, Omoe K, Inoue F, Yasujima M, Nakane A. Superantigenic Toxin Genes Coexist with Specific Staphylococcal Cassette Chromosome mec Genes in Methicillin-Resistant Staphylococcus aureus. TOHOKU J EXP MED 2011; 225:161-9. [DOI: 10.1620/tjem.225.161] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Dong-Liang Hu
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine
| | - Edward K Maina
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine
| | - Katsuhiko Omoe
- Department of Veterinary Medicine, Faculty of Agriculture, Iwate University
| | - Fumio Inoue
- Department of Clinical Laboratory, Hirosaki University Hospital
| | - Minoru Yasujima
- Department of Clinical Laboratory, Hirosaki University Hospital
- Department of Laboratory Medicine, Hirosaki University Graduate School of Medicine
| | - Akio Nakane
- Department of Microbiology and Immunology, Hirosaki University Graduate School of Medicine
| |
Collapse
|
40
|
Li SJ, Hu DL, Maina E, Shinagawa K, Omoe K, Nakane A. Superantigenic activity of toxic shock syndrome toxin-1 is resistant to heating and digestive enzymes. J Appl Microbiol 2011. [DOI: 10.1111/j.1365-2672.2011.04927.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
41
|
Wu D, Li X, Yang Y, Zheng Y, Wang C, Deng L, Liu L, Li C, Shang Y, Zhao C, Yu S, Shen X. Superantigen gene profiles and presence of exfoliative toxin genes in community-acquired meticillin-resistant Staphylococcus aureus isolated from Chinese children. J Med Microbiol 2011; 60:35-45. [PMID: 20829395 DOI: 10.1099/jmm.0.023465-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
This study aimed to evaluate the distribution of superantigen gene profiles and the presence of exfoliative toxin genes in community-acquired meticillin-resistant Staphylococcus aureus (CA-MRSA) isolated from Chinese children, and simultaneously to assess virulence gene profiles and genetic background. Of the CA-MRSA isolates, 88.9 % (88/99) harboured toxin genes, with sek as the most frequent toxin gene (62.6 %), followed by seq (61.6 %), seb (60.6 %) and sea (35.4 %). The eta gene was detected only in one ST398-IVa-spa t034 strain. The sed and etd genes were not found in any of the isolates tested. A total of 38 virulence genotypes were observed, of which the genotype seb-sek-seq (27.3 %, 24/88) comprised the majority, followed by sea-seb-sek-seq (18.2 %, 16/88). The enterotoxin gene cluster including seg-sei-sem-sen-seo-seu predominated at a rate of 15.1 %. The relationship among toxin genotypes, toxin genes encoding profiles of mobile genetic elements and genetic background was analysed. Among 66 clonal complex (CC) 59 isolates, 87.9 % (58/66) were positive for toxin genes, and 75.8 % (50/66) harboured the toxin gene combination seb-sek-seq. Among seb-sek-seq-positive CC59 strains, 42.0 % (21/50) also carried the sea gene. CC59 corresponded exclusively to accessory gene regulator 1 (agr-1). The data presented here enhance our current knowledge on the virulence determinants of CA-MRSA.
Collapse
Affiliation(s)
- Dejing Wu
- Beijing Children's Hospital, Capital Medical University, 100045 Beijing, PR China
| | - Xiangmei Li
- Beijing Children's Hospital, Capital Medical University, 100045 Beijing, PR China
| | - Yonghong Yang
- Beijing Children's Hospital, Capital Medical University, 100045 Beijing, PR China
| | - Yaojie Zheng
- Shenzhen Children's Hospital, 518026 Shenzhen, PR China
| | - Chuanqing Wang
- Pediatric Hospital of Fudan University, 201102 Shanghai, PR China
| | - Li Deng
- Guangzhou Children's Hospital, 510120 Guangzhou, PR China
| | - Lan Liu
- Chongqing Children's Hospital, 400014 Chongqing, PR China
| | - Changcong Li
- Affiliated Hospital of Wenzhou Medical College, 325000 Wenzhou, PR China
| | - Yunxiao Shang
- Shenyang Shengjing Hospital, 110003 Shenyang, PR China
| | - Changan Zhao
- Guangzhou Maternal and Child Health Hospital, 510010 Guangzhou, PR China
| | - Sangjie Yu
- Beijing Children's Hospital, Capital Medical University, 100045 Beijing, PR China
| | - Xuzhuang Shen
- Beijing Children's Hospital, Capital Medical University, 100045 Beijing, PR China
| |
Collapse
|
42
|
Larkin EA, Stiles BG, Ulrich RG. Inhibition of toxic shock by human monoclonal antibodies against staphylococcal enterotoxin B. PLoS One 2010; 5:e13253. [PMID: 20949003 PMCID: PMC2952590 DOI: 10.1371/journal.pone.0013253] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 09/13/2010] [Indexed: 01/16/2023] Open
Abstract
Background Staphylococcus aureus is implicated in many opportunistic bacterial infections around the world. Rising antibiotic resistance and few alternative methods of treatment are just two looming problems associated with clinical management of S. aureus. Among numerous virulence factors produced by S. aureus, staphylococcal enterotoxin (SE) B is a secreted protein that binds T-cell receptor and major histocompatibility complex class II, potentially causing toxic shock mediated by pathological activation of T cells. Recombinant monoclonal antibodies that target SEB and block receptor interactions can be of therapeutic value. Methodology/Principal Findings The inhibitory and biophysical properties of ten human monoclonal antibodies, isolated from a recombinant library by panning against SEB vaccine (STEBVax), were examined as bivalent Fabs and native full-length IgG (Mab). The best performing Fabs had binding affinities equal to polyclonal IgG, low nanomolar IC50s against SEB in cell culture assays, and protected mice from SEB-induced toxic shock. The orthologous staphylococcal proteins, SEC1 and SEC2, as well as streptococcal pyrogenic exotoxin C were recognized by several Fabs. Four Fabs against SEB, with the lowest IC50s, were converted into native full-length Mabs. Although SEB-binding kinetics were identical between each Fab and respective Mab, a 250-fold greater inhibition of SEB-induced T-cell activation was observed with two Mabs. Conclusions/Significance Results suggest that these human monoclonal antibodies possess high affinity, target specificity, and toxin neutralization qualities essential for any therapeutic agent.
Collapse
Affiliation(s)
- Eileen A. Larkin
- Immunology Department, Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
- Biomedical Sciences Department, Hood College, Frederick, Maryland, United States of America
| | - Bradley G. Stiles
- Immunology Department, Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
- Biology Department, Wilson College, Chambersburg, Pennsylvania, United States of America
- * E-mail: (BGS); (RGU)
| | - Robert G. Ulrich
- Immunology Department, Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
- Biomedical Sciences Department, Hood College, Frederick, Maryland, United States of America
- * E-mail: (BGS); (RGU)
| |
Collapse
|
43
|
|
44
|
Protective effect of glutathione S-transferase-fused mutant staphylococcal enterotoxin C against Staphylococcus aureus-induced bovine mastitis. Vet Immunol Immunopathol 2010; 135:64-70. [DOI: 10.1016/j.vetimm.2009.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Revised: 10/06/2009] [Accepted: 11/05/2009] [Indexed: 11/18/2022]
|
45
|
A comparative review on the pathogenicity and virulence factors of meticillin-resistant and meticillin-susceptible Staphylococcus aureus. ACTA ACUST UNITED AC 2010. [DOI: 10.1097/mrm.0b013e3283393cd4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
46
|
Emergence of a community-associated methicillin-resistant Staphylococcus aureus strain with a unique resistance profile in Southwest Nigeria. J Clin Microbiol 2009; 47:2975-80. [PMID: 19571020 DOI: 10.1128/jcm.00648-09] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Phenotypic, genotypic, and toxin gene analyses have not yet been done all in one for the Nigerian Staphylococcus aureus population. This study provides a comprehensive overview of the molecular epidemiology and genetic diversity of S. aureus strains at the largest university clinic in Ibadan, Nigeria. From 1,300 patients' clinical samples collected at the University Teaching Hospital in Ibadan, Nigeria, during a 1-year-surveillance in 2007, 346 nonduplicate S. aureus isolates were obtained. All isolates underwent antibiotic susceptibility testing, toxin gene analysis, multilocus sequence typing, agr group typing, and spa typing. For methicillin (meticillin)-resistant S. aureus (MRSA), staphylococcal cassette chromosome mec (SCCmec) typing was also performed. Of the 346 isolates, 20.23% were methicillin resistant. Thirty-three patients' isolates (47.15%) fulfilled the definition criteria for community-associated MRSA (CA-MRSA) according to a review of the medical charts. The majority of MRSA strains analyzed were isolated from surgical or pediatric patients. The commonest types of MRSA infection identified were surgical-site infections (>70%), whereas those for CA-MRSA were conjunctivitis and otitis (19 patients [57.6%]) and accidental skin and subcutaneous tissue infections (14 patients [42.4%]). The methicillin-susceptible S. aureus strains (ST1, ST5, ST15, ST7, ST8, ST25, ST30, ST72, ST80, ST121, and ST508) were heterogeneous by phenotypic and genotypic analyses. The first report of a Panton-Valentine leukocidin-positive ST88 strain (agr III, SCCmec IV) in Nigeria, as well as genetic analyses of this strain, is presented in this study. The ST88 strain was resistant to trimethoprim-sulfamethoxazole as well as to penicillin and oxacillin. CA-MRSA infections are increasing rapidly among young patients with ophthalmologic and auricular infections. Urban regions with populations of lower socioeconomic status and evidence of overcrowding appear to be at high risk for the emergence of this clone.
Collapse
|
47
|
Ohkura T, Yamada K, Okamoto A, Baba H, Ike Y, Arakawa Y, Hasegawa T, Ohta M. Nationwide epidemiological study revealed the dissemination of meticillin-resistant Staphylococcus aureus carrying a specific set of virulence-associated genes in Japanese hospitals. J Med Microbiol 2009; 58:1329-1336. [PMID: 19528142 DOI: 10.1099/jmm.0.010173-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To study comprehensive toxin profiles and the chromosomal diversity of current Japanese hospital-associated meticillin-resistant Staphylococcus aureus (HA-MRSA) strains, we conducted PCR-based identification of 28 toxin genes, and staphylococcal cassette chromosome mec (SCCmec) typing and PFGE analysis of 208 MRSA strains isolated from 100 hospitals throughout Japan. Of the tested HA-MRSA strains, 80.3 % were tst-positive. The most frequent toxin gene profile was characterized by the carriage of 13 genes, tst, sec, seg, sei, sel, sem, sen, seo, lukED, hla, hlb, hld and hlg-2. Ninety of the 208 strains had this profile, which was named pattern A. Among the 118 non-pattern A strains, 100 had similar toxin gene profiles, the concordance rates to pattern A of which were more than 80 %. Consequently, 91.3 % of the examined HA-MRSA strains carried similar toxin profiles, although PFGE patterns showed a wide variation. These strains belonged to SCCmec type II, agr II and coagulase type II. We concluded that, unlike MRSA from many other countries, most of the Japanese HA-MRSA strains belonged to, or were related to, a specific group carrying the set of 13 toxin genes, irrespective of chromosomal diversity. In addition, among the 13 toxin genes, the coexistence rates of tst, sec and sel, and those of seg, sei, sem, sen and seo, were higher than for the other toxin genes. High coexistence rates of tst, sec and sel genes suggested the presence of the pathogenicity island SaPIn1 in these strains.
Collapse
Affiliation(s)
- Teruko Ohkura
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Keiko Yamada
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Akira Okamoto
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| | - Hisashi Baba
- Department of Infectious Diseases, Nagoya University Hospital, Nagoya, Aichi, Japan
| | - Yasuyoshi Ike
- Department of Bacteriology and Bacterial Infection Control, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
| | - Yoshichika Arakawa
- Department of Bacterial Pathogenesis and Infection Control, National Institute of Infectious Diseases, Musashimurayama, Tokyo, Japan
| | - Tadao Hasegawa
- Department of Bacteriology, Nagoya City University, School of Medical Sciences, Nagoya, Aichi, Japan
| | - Michio Ohta
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
| |
Collapse
|
48
|
c-di-GMP as a vaccine adjuvant enhances protection against systemic methicillin-resistant Staphylococcus aureus (MRSA) infection. Vaccine 2009; 27:4867-73. [PMID: 19406185 DOI: 10.1016/j.vaccine.2009.04.053] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2009] [Revised: 04/11/2009] [Accepted: 04/20/2009] [Indexed: 11/22/2022]
Abstract
Cyclic diguanylate (c-di-GMP) is a novel immunomodulator and immune enhancer that triggers a protective host innate immune response. The protective effect of c-di-GMP as a vaccine adjuvant against Staphylococcus aureus infection was investigated by subcutaneous (s.c.) vaccination with two different S. aureus antigens, clumping factor A (ClfA) and a nontoxic mutant staphylococcal enterotoxin C (mSEC), then intravenous (i.v.) challenge with viable methicillin-resistant S. aureus (MRSA) in a systemic infection model. Mice immunized with c-di-GMP plus mSEC or c-di-GMP plus ClfA vaccines then challenged with MRSA produced strong antigen-specific antibody responses demonstrating immunogenicity of the vaccines. Bacterial counts in the spleen and liver of c-di-GMP plus mSEC and c-di-GMP plus ClfA-immunized mice were significantly lower than those of control mice (P<0.001). Mice immunized with c-di-GMP plus mSEC or c-di-GMP plus ClfA showed significantly higher survival rates at day 7 (87.5%) than those of the non-immunized control mice (33.3%) (P<0.05). Furthermore, immunization of mice with c-di-GMP plus mSEC or c-di-GMP plus ClfA induced not only very high titers of immunoglobulin G1 (IgG1), but c-di-GMP plus mSEC also induced significantly higher levels of IgG2a, IgG2b and IgG3 compared to alum adjuvant (P<0.01 and P<0.001, respectively) and c-di-GMP plus ClfA induced significantly higher levels of IgG2a, IgG2b and IgG3 compared to alum adjuvant (P<0.001). Our results show that c-di-GMP should be developed as an adjuvant and immunotherapeutic to provide protection against systemic infection caused by S. aureus (MRSA).
Collapse
|
49
|
Aragón-Sánchez J, Lázaro-Martínez JL, Quintana-Marrero Y, Hernández-Herrero MJ, García-Morales E, Cabrera-Galván JJ, Beneit-Montesinos JV. Are diabetic foot ulcers complicated by MRSA osteomyelitis associated with worse prognosis? Outcomes of a surgical series. Diabet Med 2009; 26:552-5. [PMID: 19646197 DOI: 10.1111/j.1464-5491.2009.02714.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS The aim of this study was to compare the outcomes of surgical treatment of osteomyelitis caused by methicillin-resistant Staphylococcus aureus (MRSA) with cases caused by methicillin-sensitive Staphylococcus aureus (MSSA). METHODS We abstracted data of a series of 185 consecutive patients with diabetes and foot osteomyelitis undergoing surgery within the first 12 h after admission at a single hospital. Bone infection was confirmed by histopathological studies. Only cases where Staphylococcus aureus was isolated from bone specimens were included in this analysis. We analysed several variables between the two groups: MRSA vs. MSSA. RESULTS MRSA bone infection was associated with higher body temperature (P = 0.02) and white blood cell count (P = 0.02) than MSSA. Patients with MRSA infections underwent a greater number of surgical procedures (P = 0.03). Limb salvage was achieved in 93.6% of the patients, with no statistically significant difference in limb salvage rates between MRSA and MSSA-related osteomyelitis. CONCLUSIONS From our experience, where treatment is based on early and aggressive surgical treatment, MRSA bone infections are not associated with worse prognosis.
Collapse
Affiliation(s)
- J Aragón-Sánchez
- Diabetic Foot Unit, La Paloma Hospital, Las Palmas de Gran Canaria, Canary Islands, Spain.
| | | | | | | | | | | | | |
Collapse
|