Detección de genes que codifican hemolisinas en cepas de Staphylococcus aureus aisladas en pantallas de teléfonos móviles de estudiantes de último año de odontología en Cuenca-Ecuador, 2020-2021 / Detection of hemolysin-encoding genes in Staphylococcus aureus strains isolated from cell phone screens of senior dental students in Cuenca-Ecuador, 2020-2021

Staphylococcus aureus es la especie más común implicada en las enfermedades infecciosas que causan morbilidad y mortalidad a nivel mundial. Posee los genes hla, hlb, hld, hlg, hlg-v que codifican para hemolisinas. Las hemolisinas son reconocidas como un factor de virulencia potencial que ataca a la membrana y produce destrucción de las plaquetas y necrosis. Tienen la capacidad de sobrevivir por largos periodos en superficies inertes como en pantallas de teléfonos móviles. Estudio observacional de tipo transversal descriptivo. Se aislaron en un estudio previo 16 cepas de Staphylococcus aureus a partir de 92 muestras de pantallas de teléfonos móviles de estudiantes de odontología. Se utilizó la técnica de reacción en cadena de la polimerasa para detectar los genes que codifican para hemolisinas. El gen hla se detectó en 75% (12/16) de cepas de Staphylococcus aureus, hlb en 25% (4/16), hld 75% (12/16), hlg 75% (12/16), hlg-v 13% (2/16). Este estudio evidencia el alto porcentaje de cepas virulentas que poseen genes que codifican para hemolisinas en pantallas de teléfonos móviles, lo que puede contribuir a la diseminación de este patógeno. Es imperioso implementar medidas para la desinfección de teléfonos móviles (AU)

Staphylococcus aureus is the most common species implicated in infectious diseases causing morbidity and mortality worldwide. It has the hla, hlb, hld, hlg, hlg-v genes encoding for hemolysins. Hemolysins are recognized as a potential virulence factor that attacks the membrane and causes platelet destruction and necrosis. They have the ability to survive for long periods on inert surfaces such as cell phone screens. Observational descriptive cross-sectional study. Sixteen strains of Staphylococcus aureus were isolated in a previous study from 92 samples of cell phone screens of dental students; the polymerase chain reaction technique was used to detect genes coding for hemolysins. The hla gene was detected in 75% (12/16) of Staphylococcus aureus strains, hlb in 25% (4/16), hld 75% (12/16), hlg 75% (12/16), hlg-v 13 % (2/16). This study evidences the high percentage of virulent strains that possess genes encoding for hemolysins in cell phone screens, which may contribute to the dissemination of this pathogen. It is imperative to implement measures for the disinfection of cell phones (AU)

Titulación de hemolisinas en concentrados plaquetarios obtenidos a partir de buffy coat de donantes voluntarios de sangre de grupo O Rh D positivo / Hemolysin titration in platelet concentrates obtained from buffy coat of voluntary blood donors of group O Rh D positive

Los posibles efectos adversos que se producen en transfusiones incompatibles ABO son un riesgo latente en el uso de concentrados de plaquetas grupo O, por lo que la titulación de hemolisinas anti-A/B constituye una de las estrategias para su prevención. El objetivo de este estudio fue determinar la frecuencia de títulos de hemolisinas de isotipos IgG e IgM anti-A/B en donantes de sangre. Se trató de un estudio descriptivo, transversal y aleatorio simple con un tamaño muestral de 308 muestras. Se aplicó la metodología en tubo, gel salino y anti-inmunoglobulina IgG y, mediante soluciones seriadas, se evidenció el título. Adicionalmente, se realizó una encuesta sobre los posibles factores de riesgo para el aumento de estos títulos. Se aplicó estadística descriptiva mediante el uso del software informático SPSS versión 22.0 y la relación entre variables independientes a través del análisis estadístico de Chi-cuadrado y, para establecer la concordancia de las lecturas visuales de las tarjetas de gel, se aplicó el índice kappa. Se determinó la existencia de hemolisinas de isotipo IgG e IgM anti-A/B de títulos superiores a 1/64. Existió una relación estadísticamente significativa entre embarazos y títulos de IgG anti-A/B >1/128 y el aumento de hemolisinas de isotipo IgM y la ingesta de probióticos. Los resultados demostraron la necesidad de implementar la titulación de hemolisinas previo a la transfusión de concentrados plaquetarios no isogrupo, por lo que se recomienda una investigación de riesgo-beneficio y el seguimiento de pacientes con transfusiones de concentrados plaquetarios incompatibles ABO.

The possible adverse effects that occur in incompatible ABO transfusions are a latent risk in the use of group O platelet concentrates, so the titration of anti-A/B hemolysins is one of the strategies for its prevention. The objective of this study was to determine the frequency of hemolysins titers IgG and IgM anti-A/B isotypes in blood donours. It was a simple randomized descriptive cross-sectional study with a sample size of 308 samples. The methodology was applied in tube, saline gel and anti-IgG anti-immunoglobulin and by means of serial solutions the title was verified. Additionally, a survey was conducted on the possible risk factors for the increase in securities. Descriptive statistics were used through the application of the SPSS version 22.0 software and the relationship between independent variables through the Chi-square statistical analysis and the kappa index was applied to match the visual readings of the gel cards. The existence of IgG and IgM anti-A/B isotype hemolysins of titers greater than 1/64 was determined. There was a statistically significant relationship between pregnancies and anti-A/B IgG titres>1/128; and the increase in IgM isotype hemolysins and probiotic intake. The results demonstrate the need to implement hemolysin titration prior to transfusion of non-isogroup platelet concentrates, so a risk-benefit investigation and follow-up of patients with transfusions of ABO incompatible platelet concentrates is recommended.

Os possíveis efeitos adversos que ocorrem em transfusões incompatíveis ABO são um risco latente no uso de concentrados de plaquetas do grupo O, portanto a titulação de hemolisinas anti-A/B é uma das estratégias para sua prevenção. O objetivo deste estudo foi determinar a frequência de títulos de hemolisinas de isotipos IgG e IgM anti-A/B em doadores de sangue. Trata-se de um estudo descritivo transversal aleatório simples, com tamanho de amostra de 308 amostras. A metodologia foi aplicada em tubo, gel salino e anti-imunoglobulina IgG e utilizando soluções em série, o título foi verificado. Além disso, foi realizada uma pesquisa sobre os possíveis fatores de risco para o aumento destes títulos. A estatística descritiva foi utilizada através da aplicação do software informático SPSS versão 22.0 e a relação entre variáveis independentes por meio da análise estatística do qui-quadrado e, para estabelecer a concordância com as leituras visuais dos cartões de gel, o índice kappa foi aplicado. Foi determinada a existência de hemolisinas de isotipo IgG e IgM anti-A/B de títulos maiores que 1/64. Existiu uma relação estatisticamente significante entre gestações e títulos de IgG anti-A/B>1/128; e o aumento de hemolisinas do isotipo IgM e a ingestão de probióticos. Os resultados demonstram a necessidade de implementar a titulação da hemolisina antes da transfusão de concentrados de plaquetas não isogrupo, por isso, recomenda-se uma investigação de risco-benefício e acompanhamento de pacientes com transfusões de concentrados de plaquetas incompatíveis com ABO.

Advance in toxic and pathogenic mechanisms of bacterial hemolysins / 中国人兽共患病学报

Many bacterial pathogens can produce hemolysins to lyse erythrocytes,but recent studies revealed that bacterial hemolysins could cause injury and death of many nucleated cells and platelets.According to the difference of molecular structure,cell-binding manner and membrane pore-forming mechanism,most of bacterial hemolysins are classified into the toxins belonging to either repeats in toxin family (RTX) or cholesterol-dependent cytolysin family (CDC).Bacterial hemolysins play important pathogenic roles during infection of bacteria through membrane damage,cell lysis or disruption,ion disequilibriumassociated pathological changes,cell apoptosis or cell necroptosis as well as through TLR2/4-mediated NF-κB,p38MAPK,JNK signaling pathways and NLRs-mediated NLRP3 inflammasomes to cause powerful inflammatory reaction and inflammatory tissue injury.

Impact of brief exposure to antifungal agents on the post-antifungal effect and hemolysin activity of oral Candida albicans

AbstractPost-antifungal effect (PAFE) of Candida and its production of hemolysin are determinants of candidal pathogenicity. Candida albicans is the foremost aetiological agent of oral candidosis, which can be treated with polyene, azole, and echinocandin antifungals. However, once administered, the intraoral concentrations of these drugs tend to be subtherapeutic and transient due to the diluent effect of saliva and cleansing effect of the oral musculature. Hence, intra-orally, Candidamay undergo a brief exposure to antifungal drugs.Objective Therefore, the PAFE and hemolysin production of oral C. albicans isolates following brief exposure to sublethal concentrations of the foregoing antifungals were evaluated.Material and Methods A total of 50 C. albicans oral isolates obtained from smokers, diabetics, asthmatics using steroid inhalers, partial denture wearers and healthy individuals were exposed to sublethal concentrations of nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole for 60 min. Thereafter, the drugs were removed and the PAFE and hemolysin production were determined by previously described turbidometric and plate assays, respectively.Results Nystatin, amphotericin B, caspofungin and ketoconazole induced mean PAFE (hours) of 2.2, 2.18, 2.2 and 0.62, respectively. Fluconazole failed to produce a PAFE. Hemolysin production of these isolates was suppressed with a percentage reduction of 12.27, 13.47, 13.33, 8.53 and 4.93 following exposure to nystatin, amphotericin B, caspofungin, ketoconazole and fluconazole, respectively.Conclusions Brief exposure to sublethal concentrations of antifungal drugs appears to exert an antifungal effect by interfering with the growth as well as hemolysin production of C. albicans.

Characteristics of hemolytic activity induced by the aqueous extract of the Mexican fire coral Millepora complanata

Background Millepora complanata is a plate-like fire coral common throughout the Caribbean. Contact with this species usually provokes burning pain, erythema and urticariform lesions. Our previous study suggested that the aqueous extract of M. complanata contains non-protein hemolysins that are soluble in water and ethanol. In general, the local damage induced by cnidarian venoms has been associated with hemolysins. The characterization of the effects of these components is important for the understanding of the defense mechanisms of fire corals. In addition, this information could lead to better care for victims of envenomation accidents.Methods An ethanolic extract from the lyophilized aqueous extract was prepared and its hemolytic activity was compared with the hemolysis induced by the denatured aqueous extract. Based on the finding that ethanol failed to induce nematocyst discharge, ethanolic extracts were prepared from artificially bleached and normal M. complanata fragments and their hemolytic activity was tested in order to obtain information about the source of the heat-stable hemolysins.Results Rodent erythrocytes were more susceptible to the aqueous extract than chicken and human erythrocytes. Hemolytic activity started at ten minutes of incubation and was relatively stable within the range of 28-50°C. When the aqueous extract was preincubated at temperatures over 60°C, hemolytic activity was significantly reduced. The denatured extract induced a slow hemolytic activity (HU50= 1,050.00 ± 45.85 μg/mL), detectable four hours after incubation, which was similar to that induced by the ethanolic extract prepared from the aqueous extract (HU50= 1,167.00 ± 54.95 μg/mL). No significant differences were observed between hemolysis induced by ethanolic extracts from bleached and normal fragments, although both activities were more potent than hemolysis induced by the denatured extract.Conclusions The results showed that the aqueous extract of M. complanata possesses one or more powerful heat-labile hemolytic proteins that are slightly more resistant to temperature than jellyfish venoms. This extract also contains slow thermostable hemolysins highly soluble in ethanol that are probably derived from the body tissues of the hydrozoan.(AU)

Characteristics of hemolytic activity induced by the aqueous extract of the Mexican fire coral Millepora complanata

Background Millepora complanata is a plate-like fire coral common throughout the Caribbean. Contact with this species usually provokes burning pain, erythema and urticariform lesions. Our previous study suggested that the aqueous extract of M. complanata contains non-protein hemolysins that are soluble in water and ethanol. In general, the local damage induced by cnidarian venoms has been associated with hemolysins. The characterization of the effects of these components is important for the understanding of the defense mechanisms of fire corals. In addition, this information could lead to better care for victims of envenomation accidents.Methods An ethanolic extract from the lyophilized aqueous extract was prepared and its hemolytic activity was compared with the hemolysis induced by the denatured aqueous extract. Based on the finding that ethanol failed to induce nematocyst discharge, ethanolic extracts were prepared from artificially bleached and normal M. complanata fragments and their hemolytic activity was tested in order to obtain information about the source of the heat-stable hemolysins.Results Rodent erythrocytes were more susceptible to the aqueous extract than chicken and human erythrocytes. Hemolytic activity started at ten minutes of incubation and was relatively stable within the range of 28-50°C. When the aqueous extract was preincubated at temperatures over 60°C, hemolytic activity was significantly reduced. The denatured extract induced a slow hemolytic activity (HU50= 1,050.00 ± 45.85 g/mL), detectable four hours after incubation, which was similar to that induced by the ethanolic extract prepared from the aqueous extract (HU50= 1,167.00 ± 54.95 g/mL). No significant differences were observed between hemolysis induced by ethanolic extracts from bleached and normal fragments, although both activities were more potent than hemolysis induced by the denatured extract...

Atividade hemolítica e produção de tubos germinativos relacionados ao potencial patogênico de isolados clínicos de Candida albicans / Hemolytic activity and production of germ tubes related to pathogenic potential of clinical isolates of Candida albicans

We assessed the virulence factor profile and in vitro antifungal susceptibility of 27 hospital isolates of C. albicans; 19 of these were from infections (16 urinary and three blood), and the other eight were isolated from sites of colonization (two from hands of health professionals, and six from central venous catheters). The virulence factors assayed were germ tube formation and production of extracellular products (hemolysins, proteinases, and phospholipases). Susceptibility to fluconazole, itraconazole, voriconazole and amphotericin B was determined by E-test. Regarding the virulence factors, the infection isolates produced significantly more hemolysin and germ tubes than the colonization isolates (p<0.05). There were no significant differences in the production of other factors between isolates from the two sources (p>0.05). Amphotericin B showed the lowest minimum inhibitory concentrations for all the isolates. The highest resistance was observed for the azoles, especially in the clinical isolates. These results suggest that the capacity of C. albicans to produce hemolysins and germ tubes may be associated with its pathogenic potential. Colonization isolates may pose a high risk of nosocomial infection, especially when the yeasts show resistance to antifungals.

O perfil de virulência e o de susceptibilidade in vitro aos antifúngicos de 27 amostras de C. albicans de origem hospitalar foi avaliado, sendo que 19 delas foram isoladas de infecções (16 urinárias e três sanguíneas) e as outras oito foram isoladas de colonização (duas de mãos de profissionais da saúde e seis de cateter venoso central). Os seguintes fatores de virulência foram investigados: formação de tubo germinativo e produção de compostos extracelulares (hemolisinas, proteinases e fosfolipases). Suscetibilidade ao fluconazol, itraconazol, voriconazol e anfotericina B foram determinadas por E-test. Em relação aos fatores de virulência, os isolados de infecção produziram significativamente mais hemolisina e tubos germinativos do que os de colonização (p<0.05). Não houve diferença significativa na produção das outras enzimas, entre os isolados das duas fontes (p>0.05). Anfotericina B mostrou as menores concentrações inibitórias mínimas para todos os isolados. Maiores índices de resistência foram observados aos azólicos, especialmente entre os isolados clínicos. Estes resultados sugerem que a capacidade de C. albicans produzir hemolisinas e tubos germinativos pode estar associada com seu potencial patogênico. Por outro lado, leveduras em colonização podem oferecer alto risco para infecção hospitalar, especialmente quando têm perfil de resistência aos antifúngicos.

Freqüência de hemolisinas anti-A e anti-B em doadores de sangue de Itapeva e Ourinhos / Anti-A and anti-B hemolysin frequencies in blood donors from Itapeva and Ourinhos

Uma transfusão de sangue com o tipo ABO incorreto pode resultar na morte dopaciente, com reação hemolítica intravascular, seguida de alterações imunológicas e bioquímicas. Considerando a pequena quantidade de estudos sobre as hemolisinas anti-A e anti-B e a importância desses anticorpos na prática transfusional, o objetivodeste trabalho foi verificar a frequência dessas hemolisinas e a associação a fatores como etnia e gênero em doadores de sangue dos bancos de sangue dos municípios de Itapeva e de Ourinhos, no interior do estado de São Paulo. Foram analisadas todas asamostras de doadores tipo O cadastradas nos bancos de sangue, com elevado nível plasmático de hemolisinas (doadores considerados perigosos). Coletaram-se os dados relativos à frequência das hemolisinas, etnia, gênero e procedência destes doadores.A frequência de doadores de sangue do grupo sanguíneo O perigosos é de 1,2%em Itapeva e de 5,3% em Ourinhos. Na cidade de Ourinhos, o risco de um doadorbranco ter hemolisina positiva é 2,16 vezes maior do que para outros doadores, e na cidade de Itapeva notou-se que o risco é menor para brancos do que para outros doadores. Em relação ao gênero, em Ourinhos o risco de um doador ter hemolisina positiva é 1,82 vezes maior para o gênero masculino, e na cidade de Itapeva, o risco foi maior para doadores do gênero feminino. A relação entre o gênero, a etnia e a frequência de hemolisinas foi diferente nas duas cidades. Mesmo assim, destaca-se a importância dos bancos de sangue estarem atentos às características de prevalência deste tipo de doador.

Blood transfusion using unmatched ABO blood types can result in patient death due to intravascular hemolytic reactions followed by immunological and biochemical changes. Considering the small number of studies on anti-A and anti-B hemolysins and the relevanceof these antibodies in the transfusional practice, this work aimed at assessing the frequency of these hemolysins and their relationship to factors such as ethnic background and gender in blood donors of blood banks located in Itapeva and Ourinhos, São Paulo State, Brazil. All samples from type O donors recorded in these two blood banks with high serum levels of hemolysins (donations considered high-risk) were analyzed. Data related to hemolysin frequencies, ethnicity, gender and origin of blood donors were collected. Thefrequency of donors belonging to the high-risk O blood group was 1.2% in Itapeva and 5.3% in Ourinhos. In Ourinhos the risk of a Caucasian donor being positive for hemolysin is 2.16 times higher than other ethnic groups and in Itapeva, it was observed that therisk is lower for Caucasians than other ethnic groups. Regarding the gender, in Ourinhos the risk of a donor being positive to hemolysin is 1.82 times greater in men and in Itapeva the risk ishigher in women. The ratios of gender and ethnic background in respect to frequency were different between the two regions. Thus it is important for blood banks to be aware of regional variations.

Flow cytometry analysis of unusual peripheral monocyte population / 中华检验医学杂志

Objective To analyze a population of cells on the right lower lateral of monocyte population in forward scatter/side scatter(FSC/SSC)(X-axis/Y-axis)scatterplot of peripheral blood leucocyte by flow cytometry(FCM)and its influencing factors.Methods The type of cells were identified based on cluster of differentiation antigen(CD)by FCM.The impact of temperature,hemolysin concentration,and incubation time was evaluated.Blood lipid tests were performed to observe the relation between them by statistical methods.Results (1) Phenotypo of this population of cells on the right lower lateral of monocytes in FSc/SSC scatterplot is CD+45 CD+13 CD+14 CD3- CD-19 ,which was the same as monocyte cells:(2)The monocytes in FSC/SSC scatterplot shifted to left side after using haemolysin;(3)The monocytes showed less resistance to antihemolysin in 37℃ than that in 220C:There were more monocytes shifting to left side with the increase of haemolysis time:(4)The swarming ratio of monocytes in patients (31.5%,40/126) Was higher than it in normal controls (5.1%,5/98)(x2=22.74,P<0.01);(5)The levels of total serum cholesterol(TC),triglyeride(TG),low density lipoprotein cholesterol(LDL-C), apoprotein B100(Apo B100) in patients with swarming monocytes were lower than that in the patients without swarming monocytes,(P<0.05).There was no statistical significance between the two groups with respect to levels of total bilirubin(TBIL),albumin(Alb),hish density lipoprotein cholesterol(HDL-C),apoprotein A I(Apo A I),lipoprotein(Lpa).Conclusions Peripheral blood monocytes can be divided in two groups in FSC/SSC scatterplot when analyzed with FCM.The presence of this population of cell Was related to resistance to hemolysin.It can be influenced by haemolysis time and incubation temperature.Therefore,the effect of swarming monocytes and abnormal cell membrane should be taken into consideration when the markers and function of monocytes are detected by FCM.

Cloning of the pneumolysin gene / 中国耳鼻咽喉头颈外科

OBJECTIVE To prepare pneumolysin(Pn)by genetic engineering and thereby establish the basis for the study of vaccines against otitis media. METHODS A pair of primers including two restriction sites was designed based on the pneumolysin gene sequence reported by Walker in 1987. The pneumolysin gene was PCR-amplified from pneumococcal DNA. The resulting fragment, digested by restriction enzymes, was ligated into the vector PET-28a and then transformed into host cell E.coli JM109(DE3). RESULTS The sequence of the inserted pneumolysin gene was confirmed by DNA sequencing. CONCLUSION The pneumolysin gene was successfully cloned into the host cell.