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1.
Aims: To investigate the distribution of staphylococcal enterotoxin genes (se) and the molecular features of community‐associated methicillin‐sensitive/resistant Staphylococcus aureus (CA‐MSSA/MRSA) isolates in the nostrils of healthy pets and their owners. Methods and Results: A total of 114 Staph. aureus isolates were identified from 1563 nasal swab samples, and CA‐MRSA accounted for 20·2% (n = 23) of the total identified isolates. CA‐MRSA isolates (91·3%, 21/23) harboured higher percentage of se than did CA‐MSSA isolates (58·2%, 53/91) (P < 0·01), and the two highest se profiles of CA‐MRSA were seb‐sek‐seq (42·9%, 9/21) and seb‐sek‐seq‐sep (28·6%, 6/21). Of the MSSAs, 42·8% (39/91) were resistant to at least one antimicrobial drug and 8·8% (8/91) were multidrug resistant (MDR). We identified nine staphylocoagulase (SC) types (I–VIII and X) and three multilocus sequence types (ST59‐MRSA‐IV/V, ST‐239‐MRSA‐V and ST241‐MRSA‐V). SC VII (23·4%, 22/94), a staphylococcal food poisoning isolate found mainly in Japan, and ST‐59‐MRSA‐IV/V (85%, 17/20), a widespread CA‐MRSA clone found mainly in Taiwan, both were the most predominant types. Phylogenetic analysis together with se and molecular characteristics obtained using pulsed‐field gel electrophoresis showed that high levels of antimicrobial resistance and the se‐carrying clone ST59‐MRSA‐IV/V‐SC VII were all clustered in genogroup 5. Conclusions: The CA‐MRSA clone of se‐carrying‐MDR‐ST‐59‐IV/V‐SC VII was identified predominantly in this study, and this clone might play a significant role in staphylococcal food poisoning in community settings. Significance and Impact of the Study: To our knowledge, this is the first study focussing on enterotoxin‐carrying CA‐MRSA/MSSA in pets and their owners, and the results support the future warnings in animal–human bond caused by CA‐staphylococci in the commonwealth and the need to take cautions worldwide. 相似文献
2.
Wang Y Yang J Logue CM Liu K Cao X Zhang W Shen J Wu C 《Journal of applied microbiology》2012,112(4):623-630
Aims: To determine the prevalence of carriage of methicillin‐resistant Staphylococcus pseudintermedius (MRSP) among dogs with pyoderma from two small animal hospitals in North China during a 21‐month period and to characterize these isolates. Methods and Results: Swabs were taken from 260 dogs with pyoderma, and the staphylococcal species isolated and methicillin resistance were confirmed phenotypically and genotypically. The identified MRSP isolates were characterized by multilocus sequence typing (MLST), spa typing, staphylococcal cassette chromosome (SCC) mec typing, testing for susceptibility to nine antimicrobial agents and SmaI‐digested pulsed‐field gel electrophoresis. Thirty‐three (12·7%) dogs were positive for MRSP. The most prevalent genotypes detected among MRSP were ST71(MLST)‐t06(spa)‐II‐III(SCCmec) (n = 22, 66·7%), followed by ST5‐t19 (n = 8, 24·2%), ST126‐III(n = 2, 6·1%) and ST6‐t02‐V (3·0%). All MRSP isolates showed extended resistance to tested antimicrobial agents. Eight different SmaI patterns were observed in 21 typeable MRSP isolates. Conclusions: Clinical isolates of MSRP isolated from dogs in North China belonged to two major clonal lineages ST71 and ST5. Significance and Impact of the Study: This study is the first report on MRSP from canine pyoderma in China. Further surveillance study is needed to gain more detailed data concerning this major clinical challenge in veterinary medicine. 相似文献
3.
L. O’Connor M. O’Leary N. Leonard M. Godinho C. O’Reilly J. Egan R. O’Mahony 《Letters in applied microbiology》2010,51(5):490-498
Aim: To enhance the information pertaining to the epidemiology of a collection of 378 Listeria spp. isolates obtained from several food‐processing plants in Ireland over a 3‐ year period (2004–2007). Methods and results: The collection was characterized by pulsed‐field gel electrophoresis (PFGE). The most prevalent pulse‐type was PFGE profile I (n = 14·5%) that consisted mainly of environmental Listeria spp. samples. Serotyping of 145 Listeria monocytogenes isolates was performed. The most common serovar was 1/2a and comprised 57·4% (n = 77) of the L. monocytogenes collection. The other serovars were as follows: 4b (14·1%, n = 19), 1/2b (9·7%, n = 13), 4c (4·4%, n = 6) and 1/2c (6·7%, n = 9), respectively. Eleven isolates were identified as non‐Listeria spp., the remaining ten L. monocytogenes isolates were nontypeable. The antimicrobial susceptibility testing revealed the antibiotic that isolates displayed the most resistance to was gentamicin (5%) followed by sulfamethoxazole‐trimethoprim (2%), tetracycline and ciprofloxacin (1·5%). Conclusions: The subtyping has indicated the diversity of the Listeria spp. The presence of serotype 1/2a, 1/2b and 4b in both raw and cooked ready‐to‐eat food products is a public health concern, as these serotypes are frequently associated with foodborne outbreaks and sporadic cases of human listeriosis. In addition, the emergence of antimicrobial‐resistant L. monocytogenes isolates could have serious therapeutic consequences. Significance and Impact of Study: The molecular subtyping and the further characterization of these isolates may be valuable particularly in the context of a suspected common source outbreak in the future. 相似文献
4.
Aim: To conduct epidemiological and ecological surveillance of cholera in freshwater environments. Methods and Results: A freshwater region of India was surveyed between April 2007 and December 2008. Vibrio cholerae was isolated from 59·5% of water and plankton samples (n = 357) and 35·5% of stool samples (n = 290). Isolation from water was dependent on air (r = 0·44) and water temperatures (r = 0·49) (P < 0·01) but was independent of rainfall (r = 0·15), chlorophyll a (r = 0·18), salinity (r = 0·2) or pH (r = 0·2) (P > 0·05). Isolation from plankton was dependent on temperature of air (r = 0·45), water temperature (r = 0·44), chlorophyll a concentration (r = 0·42), pH (r = 0·23) and salinity (r = 0·39) (P < 0·01). Cholera cases correlated with rainfall (r = 0·82, P < 0·01) and chlorophyll a concentration (r = 0·42, P < 0·05), but not with air temperature (r = 0·3, P = 0·37). Vibrio cholerae O1 possessed ctxB, ctxA, rstR and tcpA (ElTor), toxR, toxT, rtxA, rtxC, mshA and hylA. Among non‐O1–non‐O139, the distribution of virulence‐associated and regulatory protein genes was heterogeneous with – 0·7, 2·2, 94·77, 97·76, 99·25, 100 and 100% isolates being positive for tcpA, toxT, rtxA, rtxC, hylA, toxR and mshA, respectively. Two‐thirds of non‐O1–non‐O139 isolates exhibited antibiotic resistance to various antibiotics that did not correlate with geographical site or time of origin for the isolates. RAPD and AFLP showed V. cholerae to be a diverse bacterium. AFLP demonstrated separate lineages for non‐O1–non‐O139 and O1 isolates. Conclusion: Environmental parameters played a significant role in the emergence and spread of cholera and the abundance of V. cholerae. But based on virulence gene profiling and genetic fingerprinting, the possibility of origin of toxigenic isolates from nontoxigenic environmental isolates seems unlikely in freshwater environs of India. Significance and Impact of the Study: This study explains the ecology, epidemiology and seasonality of cholera in freshwater environs. 相似文献
5.
E.L. Sproston I.D. Ogden M. MacRae K.J. Forbes J.F. Dallas S.K. Sheppard A. Cody F. Colles M.J. Wilson N.J.C. Strachan 《Journal of applied microbiology》2010,109(3):829-838
Aims: To assess whether flies and slugs acquire strains of Campylobacter jejuni and Campylobacter coli present in local ruminant faeces. Methods and Results: Campylobacter was cultured from flies, slugs and ruminant faeces that were collected from a single farm in Scotland over a 19‐week period. The isolates were typed using multi‐locus sequence typing (MLST) and compared with isolates from cattle and sheep faeces. Campylobacter jejuni and Camp. coli were isolated from 5·8% (n = 155, average of 75 flies per pool) and 13·3% (n = 15, average of 8·5 slugs per pool) of pooled fly and slug samples, respectively. The most common sequence type (ST) in flies was Camp. coli ST‐962 (approx. 40%) regardless of the prevalence in local cattle (2·3%) or sheep (25·0%) faeces. Two positive slug pools generated the same ST that has not been reported elsewhere. Conclusions: Despite their low carriage rate, flies are able to acquire Campylobacter STs that are locally present, although the subset carried may be biased when compared to local source. Slugs were shown to carry a previously unreported Campylobacter ST. Significance and Impact of the Study: This study has demonstrated that flies carry viable Campylobacter and may contribute to the transfer of STs within and between groups of animals on farms. Further, they may therefore present a risk to human health via their contact with ready‐to‐eat foods or surfaces. 相似文献
6.
Antimicrobial resistance and toxin gene profiles of Staphylococcus aureus strains from Holstein milk 总被引:1,自引:0,他引:1
Y. Wang G. Guo T. Usman D. Hao X. Tang Y. Zhang Y. Yu 《Letters in applied microbiology》2014,58(6):527-534
Isolation of Staphylococcus aureus (Staph. aureus) from Holstein milk samples with mastitis and nonmastitis was conducted to estimate its prevalence, antimicrobial resistance and toxin genes. A total of 353 milk samples were collected from three Chinese Holstein herds. Fifty‐three Staph. aureus isolates collected from 29 Staph. aureus‐positive samples were characterized via antimicrobial susceptibility, toxin genes and Pulsed‐field Gel Electrophoresis (PFGE) profiles. The prevalence of Staph. aureus was 4·0–9·5% in mastitic and 7·3–11·5% in nonmastitic samples in the analysed herds. Approximately 61·0% of Staph. aureus strains isolated from mastitis cows were resistant to ≥10 antimicrobials compared with 0% of isolates with nonmastitis. The most frequently observed super antigenic toxin gene was pvl (41·5%) followed by seh + pvl (13·2%). We did not find mecA‐positive methicillin‐resistant Staph. aureus (MRSA) strains, while mecA‐negative MRSA strains were identified in the three herds. PFGE results suggested potential transmission of Staph. aureus strains in different farms. These results open new insights into Staph. aureus transmission and antimicrobial resistance of Holstein dairy cows and into developing strategies for udder health improvement of dairy cattle. 相似文献
7.
Aims: The objective of the study was to determine the prevalence of methicillin‐resistant Staphylococcus aureus (MRSA) contamination of retail meat and to determine the level of contamination. Methods and Results: Pork (pork chops and ground pork), ground beef and chicken (legs, wings and thighs) were purchased at retail outlets in four Canadian provinces and tested for the presence of methicillin‐resistant Staph. aureus using qualitative and quantitative methods. MRSA was isolated from 9·6% of pork, 5·6% of beef and 1·2% of chicken samples (P = 0·0002). Low levels of MRSA were typically present, with 37% below the detection threshold for quantification and <100 CFU g?1 present in most quantifiable samples. All isolates were classified as Canadian epidemic MRSA‐2 (CMRSA‐2) by pulsed field gel electrophoresis (PFGE), with two different PFGE subtypes, and were spa type 24/t242. Conclusions: MRSA contamination of retail meat is not uncommon. While CMRSA‐2, a human epidemic clone, has been found in pigs in Canada, the lack of isolation of livestock‐associated ST398 was surprising. Significance and Impact of the Study: The relevance of MRSA contamination of meat is unclear but investigation is required because of the potential for exposure from food handling. Sources of contamination require investigation because these results suggest that human or animal sources could be involved. 相似文献
8.
Aims: Studies of pigeon‐borne yeasts have tended to focus on species, such as Cryptococcus neoformans and Candida albicans, with scant attention to feral pigeons in Korea. We studied the prevalence of yeasts from faecal samples of feral pigeons obtained in various public places in Seoul, Korea, and assessed their potential capacity as human pathogens. Methods and Results: Three hundred and six pigeon faeces samples were collected at city squares and parks in 21 localities in Seoul and Seoul Grand Park and analysed for yeast with conventional methods. Of the 306 samples, 126 (41·2%) were positive for yeast. Seventeen species of yeast were identified. The most frequent species were Candida glabrata (34·1%), Candida famata (12·7%), Cryptococcus albidus (14·3%) and Cryptococcus laurentii (7·9%). The yeast isolates were tested for virulence. Of the 116 isolates (ten isolates missing), 70·7% (n = 82) grew at 37°C. All the Cryptococcus spp. isolates possessed a capsule, 16·4% (n = 19) produced melanin, and 33·6% (n = 39) produced proteinase. Two Ca. glabrata, a Ca. famata and Ca. albicans as well as three C. neoformans, a C. laurentii and Ca. albicans isolates had three virulence factors. Accordingly, 29·3% (n = 34) isolates possessed more than two virulence factors except capsule formation. Conclusions: These results of this study indicate that feral pigeons harbour a variety of yeasts and are a reservoir of human pathogenic fungi. Significance and Impact of the Study: This study is the first time about the microflora (fungi) presents in faecal samples collected from a variety of public areas throughout Seoul, Korea. 相似文献
9.
Ram S Vajpayee P Tripathi U Singh RL Seth PK Shanker R 《Journal of applied microbiology》2008,105(6):1899-1908
Aims: To determine the occurrence of Escherichia coli harbouring virulence markers of shiga‐ or entero‐toxins and resistance to antimicrobials in surface waters. Methods and Results: Surface water samples were collected at six locations of the river Gomti. E. coli isolates (n = 90) were characterized for their pathogenic potential using polymerase chain reaction to detect virulence genes as well as their sensitivity to antimicrobial agents using disc diffusion methods. In this study, 57·8% of E. coli isolates exhibited resistance to three or more antimicrobial agents. Sensitivity to cephotaxime, gentamicin and norfloxacin was observed in 7·8%, 48·9% and 77·8% of isolates, respectively. Both stx1 and stx2 genes were present in 15·6% of isolates while remaining isolates had either stx1 (17·8%) or stx2 (6·7%). The stx1 gene (33·3%) was more prevalent than stx2 (22·2%). The results indicate that the LT1 and ST1 genes were positive in 21·2% of isolates. Conclusions: The presence of multi‐drug resistance and virulence genes in E. coli isolated from surface water being used for domestic and recreational purposes may result in waterborne outbreaks. Significance and Impact of the Study: The data will be useful in monitoring surface waters for forecasting and management of waterborne outbreaks. 相似文献
10.
C.S. Hölzel K.S. Harms H. Küchenhoff A. Kunz C. Müller K. Meyer K. Schwaiger J. Bauer 《Journal of applied microbiology》2010,108(5):1642-1656
Aims: Antibiotic residues as well as antibiotic‐resistant bacteria in environmental samples might pose a risk to human health. This study aimed to investigate the association between antibiotic residues and bacterial antimicrobial resistance in liquid pig manure used as fertilizer. Methods and Results: Concentrations of tetracyclines (TETs) and sulfonamides (SULs) were determined by liquid chromatography‐mass spectrometry in 305 pig manure samples; antibiotic contents were correlated to the phenotypic resistance of Escherichia coli (n = 613) and enterococci (n = 564) towards up to 24 antibiotics. In 121 samples, the concentration of the TET resistance genes tet(M), tet(O) and tet(B) was quantified by real‐time‐PCR. TETs were found in 54% of the samples. The median sum concentration of all investigated TETs in the positive samples was 0·73 mg kg?1. SULs were found with a similar frequency (51%) and a median sum concentration of 0·15 mg kg?1 in the positive samples. Associated with the detection of TETs and/or SULs, resistance rates were significantly elevated for several substances – some of them not used in farm animals, e.g. chloramphenicol and synercid. In addition, multiresistant isolates were found more often in samples containing antibiotics. Analysis of the resistance genes tet(M) and tet(O) already showed a significant increase in their concentrations – but not in tet(B) – in the lowest range of total TET concentration. Mean tet(M) concentrations increased by the factor of 4·5 in the TET concentration range of 0·1–1 mg kg?1, compared to negative manure samples. Conclusions: Antibiotic contamination of manure seems to be associated with a variety of changes in bacterial resistance, calling for a prudent use of antibiotics in farm animals. Significance and Impact of the Study: This study provides an interdisciplinary approach to assess antimicrobial resistance by combining the microbiological analysis of bacterial resistance with high quality chemical analysis of antibiotic residues in a representative number of environmental samples. 相似文献
11.
M. Tamburro G. Ripabelli I. Fanelli G. Maria Grasso M. Lucia Sammarco 《Journal of applied microbiology》2010,108(5):1602-1611
Aims: In this study, 105 Listeria monocytogenes strains isolated from humans, foods and environmental samples were characterized using several typing methods. Moreover, serotyping procedure was evaluated, and a cost‐effective methodological approach based on preliminary PCRs screening was proposed. Methods and Results: The isolates were analysed by conventional serotyping, multiplex‐PCRs for serogroup and lineage identification and PCR–RFLP of inlA gene to identify potentially noninvasive L. monocytogenes. Among the strains, only the serotypes 1/2a, 1/2c, 1/2b, 4b and 3a were identified. The isolates were classified into serogroups I (58·10%), II (22·85%), III (12·38%) and IV (6·67%). Among clinical strains, lineage I was more represented (68·75%) than lineage II; whereas, lineage II was more associated with food (90·24%) and environmental (85·72%) isolates. Most of food (89·02%) and environmental (85·71%) isolates were classified into truncated InlA profiles, whereas the 93·75% of clinical strains were associated with a complete form of the protein. Conclusion: Molecular techniques were sensitive and specific for classifying strains into serogroup and lineage and in agreement with the serotyping. Moreover, a preliminary PCRs‐based screening was proposed to select only the necessary antisera by a flow chart; this methodological approach allows cost saving up to 42%. Our results further suggest the role of InlA protein in human listeriosis, particularly in immunocompetent individuals, and a correlation between truncated protein and serotype. Significance and Impact of the Study: This study further validates molecular methods for L. monocytogenes analysis and proposed a new cost‐effective approach for serotyping. It could help to improve a national surveillance network for L. monocytogenes infections in Italy. 相似文献
12.
Aims: This study evaluates dialysis filtration and a range of PCR detection methods for identification and quantification of human adenoviruses in a range of environmental waters. Methods and Results: Adenovirus was concentrated from large volumes (50–200 l) of environmental and potable water by hollow fibre microfiltration using commercial dialysis filters. By this method, an acceptable recovery of a seeded control bacteriophage MS2 from seawater (median 95·5%, range 36–98%, n = 5), stream water (median 84·7%, range 23–94%, n = 5) and storm water (median 59·5%, range 6·3–112%, n = 5) was achieved. Adenovirus detection using integrated cell culture PCR (ICC‐PCR), direct PCR, nested PCR, real‐time quantitative PCR (qPCR) and adenovirus group F‐specific direct PCR was tested with PCR products sequenced for confirmation. Adenovirus was routinely detected from all water types by most methods, with ICC‐PCR more sensitive than direct‐nested PCR or qPCR. Group F adenovirus dominated in wastewater samples but was detected very infrequently in environmental waters. Conclusions and Implications: Human adenoviruses (HAdv) proved relatively common in environmental and potable waters when assessed using an efficient concentration method and sensitive detection method. ICC‐PCR proved most sensitive, could be used semiquantitatively and demonstrated virus infectivity but was time consuming and expensive. qPCR provided quantitative results but was c. ten‐fold less sensitive than the best methods. 相似文献
13.
Prendergast DM Duggan SJ Fanning S Cormican M Gonzales-Barron U Butler F Duffy G 《Journal of applied microbiology》2008,105(4):1209-1219
Aims: This study aimed to determine the numbers and types of Salmonella spp. and Enterobacteriaceae on pork cuts in the meat cutting room environment of four commercial pork abattoirs in the Republic of Ireland. Methods and Results: Pork oysters (M. gluteus medius; n = 720) and swabs (n = 56) from equipment and surfaces were screened for Salmonella spp. using a DNA-based PCR method and confirmed by culture. Salmonella numbers were assessed using a three-tube most probable number (MPN) technique. Salmonella spp. was detected on 24/720 (3·3%) pork cuts (range of <0·03–0·36 MPN g−1) and in 7/56 (12·5%) environmental swabs (range of <0·03–1·10 MPN cm−2). There was significant variation in the prevalence of Salmonella on pork between different abattoirs and days of sampling (range of 0–31·7%). The predominant serotype was Salmonella serotype Typhimurium followed by Salmonella serotype Derby. Conclusions: Overall prevalence data conceal the key finding that there was considerable variation in the incidence of Salmonella on different days. A direct association between Salmonella contamination of pork cuts and equipment/surfaces was observed. Significance and Impact of the Study: Prevalence and numbers of Salmonella were low; however, results clearly demonstrate the potential for cross-contamination from equipment and meat contact surfaces in the cutting room environment. 相似文献
14.
Aims: To investigate the presence of toxigenic Staphylococcus aureus in ready‐to‐eat (RTE) Korean foods and determine the distribution of genes related to various types of toxin production. Methods and Results: A total of 3293 commercial RTE refrigerated foods (sushi, n = 1882; kimbab, n = 975; California rolls, n = 436) were collected from Korean grocery stores, department stores and convenience stores between January 2006 and June 2007. Of these, 197 (5·98%) RTE samples were contaminated with coagulase‐positive Staph. aureus, that is, 61 (6·26%) kimbab, 110 (5·84%) sushi and 26 (5·96%) California rolls. Multiplex PCR determined the presence of 12 toxigenic genes: sea, seb, sec, sed, see, seg, seh, sei, sej, tst‐1, eta and etb. Approximately half (49·75%) of the Staph. aureus isolates had toxigenic properties, and most of the toxigenic isolates possessed genes coding for the simultaneous production of two or more types of toxin. The most frequent toxigenic types found in Korean RTE foods were as follows: seg = sei > sea > tst‐1 > etb > seh > eta > sec > sej. Conclusions: This study provided a comprehensive analysis of toxigenic S. aureus isolates from Korean RTE foods and their toxigenicity types. This emphasizes the potential risk of various types of toxigenic Staph. aureus in refrigerated RTE food products, which should be better managed to establish safer food chains in global food markets. Significance and Impact of the Study: This result may contribute to an extended database on Staph. aureus food contamination and mitigate the lack of available information on microbiological hazards in Southeast Asian Nations. 相似文献
15.
M. Dolejská B. Bieroová L. Kohoutová I. Literák A. íek 《Journal of applied microbiology》2009,106(6):1941-1950
Aim: To examine surface water from a pond in the northeastern part of the Czech Republic and young black‐headed gulls (Larus ridibundus) nesting on the same pond for the presence of antibiotic‐resistant Salmonella and Escherichia coli. Methods and Results: A total of 16% (n = 87) of water and 24% (n = 216) of gull samples yielded Salmonella. Salmonella Enteritidis PT8 and PT4 were the most prevalent. Antibiotic resistance was found in 12% (n = 14) of water and 28% (n = 51) of gull salmonellae. Escherichia coli were found in 83 (95%) and 213 (99%) of pond water and gull samples, respectively. Totals of 18% (n = 83) of water and 28% (n = 213) of gull E. coli isolates were resistant to antimicrobial agents tested. Class 1 integrons were found in 21% (n = 14) of water and 15% (n = 60) of gull antibiotic‐resistant E. coli isolates. Class 2 integrons and extended‐spectrum beta‐lactamase‐producing E. coli isolates (with blaCTX‐M‐1, blaCTX‐M‐15‐like, blaSHV‐2 and blaSHV‐12) were found in 13% (eight positive, n = 60 gull‐resistant E. coli isolates) and 3% (seven positive, n = 216 gull E. coli isolates) of gull isolates, respectively. Antibiotic‐resistant E. coli isolates with identical pulsed field gel electrophoresis (PFGE) patterns were found in either gulls or water, but not both. Salmonellae of the same serotype and PFGE profile were found in both gulls and water. Conclusion: A high prevalence of antibiotic‐resistant salmonellae and E. coli were found in both pond water and in sympatric black‐headed gulls. Significance and Impact of the Study: Intensive contamination of pond surface water by antibiotic‐resistant E. coli and salmonellae was documented. Black‐headed gulls were identified as important reservoirs of antibiotic‐resistant salmonellae and E. coli, including extended‐spectrum beta‐lactamase‐producing isolates. 相似文献
16.
Fumiaki Tabuchi Aroonlug Lulitanond Viraphong Lulitanond Sudaluck Thunyaharn Chikara Kaito 《Microbiology and immunology》2020,64(3):219-225
In this present study, we investigated the phenol-soluble modulin (psm-mec) mutations, the staphylococcal cassette chromosome mec (SCCmec) types, and toxin production in 102 methicillin-resistant Staphylococcus aureus (MRSA) isolates from the northeast and central regions of Thailand. The MRSA isolates carrying -7T>C psm-mec in Type II SCCmec (n = 18) and the MRSA isolates carrying no psm-mec in Type IV (n = 8) or Type IX SCCmec (n = 4) had higher hemolytic activity against sheep erythrocytes than MRSA isolates carrying intact psm-mec in Type III SCCmec (n = 34), but MRSA isolates carrying no psm-mec in Type I SCCmec (n = 27) did not. 相似文献
17.
J. Li G.‐Z. Zhao H.‐H. Chen H.‐B. Wang S. Qin W.‐Y. Zhu L.‐H. Xu C.‐L. Jiang W.‐J. Li 《Letters in applied microbiology》2008,47(6):574-580
Aims: The aim of this study was to screen antitumour and antimicrobial activities of endophytic actinomycetes isolated from pharmaceutical plants in rainforest in Yunnan province, China. Methods and Results: Antitumour activity was studied by the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay and antimicrobial activity was determined by agar well diffusion method. The high bioactive endophytic isolates were identified and further investigated for the presence of polyketide synthases (PKS‐I, PKS‐II) and nonribosomal peptide synthetases (NRPS) sequences by specific amplification. The molecular identification confirmed that the 41 isolates showed significant activities were members of the genus Streptomyces. Among them, 31·7% of endophytic streptomycete cultures were cytotoxic against A549 cells, 29·3% against HL‐60 cells, 85·4% against BEL‐7404 cells, 90·2% against P388D1 cells, 65·9% were active against Escherichia coli, 24·4% against Staphylococcus aureus, 31·7% against Staphylococcus epidermidis, 12·2% against Candida albicans and no strain displayed antagonistic activity against Klebsiella pneumoniae. High frequencies of positive PCR amplification were obtained for PKS‐I (34·1%), PKS‐II (63·4%) and NRPS (61·0%) biosynthetic systems. Conclusions: Many endophytic streptomycetes isolated from pharmaceutical plants in rainforest possess remarkable and diverse antitumour and antimicrobial bioactivities. Significance and Impact of the Study: These endophytic streptomycetes are precious resources obtained from rainforests, and they could be a promising source for bioactive agents. 相似文献
18.
19.
Matthew J. Witt Annette C. Broderick John W. Coker Michael S. Coyne Mark Dodd Michael G. Frick Matthew H. Godfrey DuBose B. Griffin Sally R. Murphy Thomas M. Murphy Kris L. Williams Brendan J. Godley 《Diversity & distributions》2011,17(4):624-640
Aim Although satellite tracking has yielded much information regarding the migrations and habitat use of threatened marine species, relatively little has been published about the environmental niche for loggerhead sea turtles Caretta caretta in north‐west Atlantic waters. Location North Carolina, South Carolina and Georgia, USA. Methods We tracked 68 adult female turtles between 1998 and 2008, one of the largest sample sizes to date, for 372.2 ± 210.4 days (mean ± SD). Results We identified two strategies: (1) ‘seasonal’ migrations between summer and winter coastal areas (n = 47), although some turtles made oceanic excursions (n = 4) and (2) occupation of more southerly ‘year‐round’ ranges (n = 18). Seasonal turtles occupied summer home ranges of 645.1 km2 (median, n = 42; using α‐hulls) predominantly north of 35 ° latitude and winter home ranges of 339.0 km2 (n = 24) in a relatively small area on the narrow shelf off North Carolina. We tracked some of these turtles through successive summer (n = 8) and winter (n = 3) seasons, showing inter‐annual home range repeatability to within 14.5 km of summer areas and 10.3 km of winter areas. For year‐round turtles, home ranges were 1889.9 km2. Turtles should be tracked for at least 80 days to reliably estimate the home range size in seasonal habitats. The equivalent minimum duration for ‘year‐round’ turtles is more complex to derive. We define an environmental envelope of the distribution of North American loggerhead turtles: warm waters (between 18.2 and 29.2 °C) on the coastal shelf (in depths of 3.0–89.0 m). Main conclusions Our findings show that adult female loggerhead turtles show predictable, repeatable home range behaviour and do not generally leave waters of the USA, nor the continental shelf (< 200m depth). These data offer insights for future marine management, particularly if they were combined with those from the other management units in the USA. 相似文献
20.
S.R. Mueller‐Spitz L.B. Stewart S.L. McLellan 《Journal of applied microbiology》2010,108(6):1994-2002
Aims: The purpose of the work was to evaluate the mCP method to correctly identify and enumerate Clostridium perfringens that are present in surface waters impacted by a mixture of faecal pollution sources. Methods: Clostridium perfringens were enumerated and isolated from sewage influent, surface water and suspended sediments using the mCP method. Molecular characterization of isolates was performed using species‐specific PCR, along with full‐length sequencing of the 16S rRNA gene for a subset of isolates. Results: The environmental isolates were presumptively identified as C. perfringens based on utilization of sucrose, inability to ferment cellobiose and a positive action for acid phosphatase activity. All isolates (n = 126) were classified as C. perfringens based on positive results with species‐specific PCR with a subset confirmed as C. perfringens based on the 16S rRNA gene identity. Conclusions: The molecular results indicated all of the presumptive positive isolates were C. perfringens regardless of the source, e.g. sewage influent or environmental water samples. Sequencing revealed that C. perfringens obtained from sewage and the aquatic environment were nearly identical (c. 99·5% similarity). Significance and Impact of the Study: From this study we conclude that the mCP method is a robust approach to enumerate and isolate C. perfringens from aquatic environments that receive diverse sources of faecal pollution. 相似文献