Cadmium exposure and risk of breast cancer: A meta-analysis.

BACKGROUND: Cadmium is a heavy metal with carcinogenic properties, highly prevalent in industrialized areas worldwide. Prior reviews evaluating whether cadmium influences breast cancer have been inconclusive and not reflected several recent studies. OBJECTIVE: To evaluate the association between cadmium exposure and female breast cancer incidence, with an emphasis on separately estimating dietary vs. airborne vs. biomarker measures of cadmium and studies published until October 2022. METHODS: We evaluated risk of bias using set criteria and excluded one study judged to have high risk based on self-report of breast cancer and insufficient adjustment. We conducted a random effects meta-analysis of epidemiological studies, including subgroups by exposure route and by menopausal status. RESULTS: A total of 17 studies were eligible for our meta-analysis. Only 2 studies addressed airborne cadmium directly. Breast cancer risk was elevated in women exposed to higher levels of cadmium across all studies - pooled odds ratio: 1.13 (95% confidence interval: 1.00, 1.28), with notable heterogeneity between studies (I2 = 77%). When examining separately by exposure route, dietary cadmium was not linked with an elevated risk - (OR: 1.05; 95%CI: 0.91, 1.21; I2 = 69%), consistent with prior reviews, but biomarker-based studies showed an elevated but non-significant pooled measure (OR: 1.37; 95%CI: 0.96, 1.94; I2 = 84%). We did not observe any clear patterns of different risk by menopausal status. CONCLUSION: Findings from our meta-analysis suggest that exposure to higher cadmium increases the risk of breast cancer in women, but with remaining questions about whether non-dietary exposure may be more risky or whether residual confounding by constituents of tobacco smoke may be at play.

Identification of a novel protein in the genome sequences of Leptospira interrogans with the ability to interact with host's components.

BACKGROUND: Leptospirosis is an infectious disease that affects humans and animals worldwide. The etiological agents of this disease are the pathogenic species of the genus Leptospira. The mechanisms involved in the leptospiral pathogenesis are not full understood. The elucidation of novel mediators of host-pathogen interaction is important in the detection of virulence factors involved in the pathogenesis of leptospirosis. OBJECTIVE: This work focused on identification and characterization of a hypothetical protein of Leptospira encoded by the gene LIC10920. METHODS: The protein of unknown function was predicted to be surface exposed. Therefore, the LIC10920 gene was cloned and the protein expressed in Escherichia coli BL21 (DE3) Star pLysS strain. The recombinant protein was purified by metal affinity chromatography and evaluated with leptospirosis human serum samples. The interaction with host components was also performed. RESULTS: The recombinant protein was recognized by antibodies present in leptopsirosis human serum, suggesting its expression during infection. Immunofluorescence and intact bacteria assays indicated that the bacterial protein is surface-exposed. The recombinant protein interacted with human laminin, in a dose-dependent and saturable manner and was named Lsa24.9, for Leptospiral surface adhesin, followed by its molecular mass. Lsa24.9 also binds plasminogen (PLG) in a dose-dependent and saturable fashion, fulfilling receptor ligand interaction. Moreover, Lsa24.9 has the ability to acquire PLG from normal human serum, exhibiting similar profile as observed with the human purified component. PLG bound Lsa24.9 was able of generating plasmin, which could increase the proteolytic power of the bacteria. CONCLUSIONS: This novel leptospiral protein may function as an adhesin at the colonization steps and may help the invasion process by plasmin generation at the bacterial cell surface.

Diarrhoeagenic Escherichia coli and Escherichia albertii in Brazil: pathotypes and serotypes over a 6-year period of surveillance.

Diarrhoeagenic Escherichia coli (DEC) is a leading cause of infectious diarrhoea worldwide. In recent years, Escherichia albertii has also been implicated as a cause of human enteric diseases. This study describes the occurrence of E. coli pathotypes and serotypes associated with enteric illness and haemolytic uremic syndrome (HUS) isolated in Brazil from 2011 to 2016. Pathotypes isolated included enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC) and Shiga toxin-producing E. coli (STEC). PCR of stool enrichments for DEC pathotypes was employed, and E. albertii was also sought. O:H serotyping was performed on all DEC isolates. A total of 683 DEC and 10 E. albertii strains were isolated from 5047 clinical samples. The frequencies of DEC pathotypes were 52.6% (359/683) for EPEC, 32.5% for EAEC, 6.3% for ETEC, 4.4% for EIEC and 4.2% for STEC. DEC strains occurred in patients from 3 months to 96 years old, but EPEC, EAEC and STEC were most prevalent among children. Both typical and atypical isolates of EPEC and EAEC were recovered and presented great serotype heterogeneity. HUS cases were only associated with STEC serotype O157:H7. Two E. albertii isolates belonged to serogroup O113 and one had the stx2f gene. The higher prevalence of atypical EPEC in relation to EAEC in community-acquired diarrhoea in Brazil suggests a shift in the trend of DEC pathotypes circulation as previously EAEC predominated. This is the first report of E. albertii isolation from active surveillance. These results highlight the need of continuing DEC and E. albertii surveillance, as a mean to detect changes in the pattern of pathotypes and serotypes circulation and provide useful information for intervention and control strategies.

Evaluation of inhibitors for development of a selective medium for isolation of Leptospira spp. from clinical samples.

This study was conducted to develop a selective medium for the detection of Leptospira spp. in clinical samples. Serovars of Leptospira spp., environmental bacteria and the fungus from contaminated cultures of patients with suspected leptospirosis were inoculated into EMJH medium containing amphotericin B, 5-fluorouracil (5-FU), furazolidone and neomycin used singly or combined. Medium with 5-FU at the concentration of 200 µg ml-1 did not show any inhibitory effect against the fungus, Gram-negative bacilli and any of the leptospira strains except serovar Pyrogenes. The highest concentration of neomycin and furazolidone that did not inhibit the growth of leptospires was 4 µg ml-1 . All strains of Leptospira spp. grew on 5-FU (100 µg ml-1 ) in combination with neomycin (4 µg ml-1 ) and on 5-FU (100 µg ml-1 ) in combination with furazolidone (4 µg ml-1 ). The highest concentration of amphotericin B (500 µg ml-1 ) that inhibited the growth of the fungus also inhibited the bacteria and most of serovars of Leptospira spp. The most effective antibiotic combinations that inhibited the majority of environmental bacteria growth without affecting leptospiral growth were EMJH with 5-FU (100 µg ml-1 ) in combination with neomycin (4 µg ml-1 ). In conclusion, these findings will help the development of new selective media to isolate leptospires. SIGNIFICANCE AND IMPACT OF THE STUDY: Leptospirosis is one of the most widespread zoonotic diseases in the world. Since certain serovars are often associated with the symptoms and severity of the disease, the isolation and identification of the leptospires usually permits the prediction of sources of infection. Attempts to isolate Leptospira spp. from clinical specimens are often frustrated by overgrowth of the slow-growing bacteria by more rapidly growing contaminants. In this study, we evaluated selective agents to develop a new selective medium to isolate leptospires. The results demonstrated that the association of drugs in concentrations that allowed the growth of leptospires is to be more effective in inhibiting bacterial contaminants.

Evaluation of the elastinolytic activity and protective effect of Leptallo I, a protein composed by metalloprotease and FA5/8C domains, from Leptospira interrogans Copenhageni.

Leptospirosis is a re-emergent zoonosis, caused by pathogenic spirochetes from the genus Lepstospira. To date, there is no protein described to be involved in leptospiral hemorrhagic manifestations, although several proteases have been reported for other bacterial infections. In this study we identified 12 putative metalloproteases from the genome of Leptospira interrogans, and characterized for the first time a putative metalloprotease, here named Leptallo I, as a potential Zn(2+) dependent glycylglycine protease belonging to the M23 metalloendopeptidase family. The native protein was detected in extracts from several pathogenic Leptospira species and further shown to be secreted to the culture medium. We expressed the recombinant protein and its C-terminal fragment containing the metalloprotease domain, and both presented regular secondary structures. The sera of humans with leptospirosis were able to recognize rLeptallo I, indicating that the native protein is expressed and presented to the immune system during infection. The recombinant proteins displayed a significant, though relatively low, elastinolytic activity, and the challenge of hamsters immunized with rLeptallo I conferred 33% protection, suggesting a significant importance of this protein in the pathogenesis. The elastinolytic activity may be important for leptospires-host interaction, because elastin constitutes a significant proportion of total lung and blood vessel proteins.

Efficacy of serum samples stored on filter paper for the detection of antibody to Leptospira spp. by microagglutination test (MAT).

The aim of this study was to investigate the microagglutination test (MAT) results in serum samples dried on filter paper and stored at different temperatures during 1day, 7days, 30days and 1year to determine the stability of sera antibody against leptospires. Serum samples collected onto filter paper for the detection of leptospires antibody was compared with MAT in a study of 300 serum samples from patients with suspected leptospirosis. Among 300 fresh serum samples analyzed by MAT 156 (52%) were positive and 144 (48%) negative. All the negative fresh serum samples were negative when dried on filter paper (specificity 100%). The sensitivity of MAT performed on dried serum samples was 100%. Storage on filter paper at room temperature and at 4°C for 1 and 7days did not affect the MAT titers. For up to 7days, 98.72% of dried serum samples had titers identical to those of the corresponding serum samples, and 1.18% of dried serum samples showed 1 dilution of difference. After a storage period of one month a prozone phenomenon was observed. After a storage period of one year all serum samples were negative. Serum samples collected onto filter paper are a convenient source of antibodies for serological diagnosis and epidemiological surveys.

Analysis of multilocus sequence typing for identification of Leptospira isolates in Brazil.

A collection of 101 Leptospira isolates was tested by multilocus sequence typing (MLST) and by traditional serotyping. MLST divided the isolates into 4 sequence types (STs), while serotyping classified them into 6 serogroups. Two isolates failed to generate products for some genes by MLST. MLST was less discriminatory than serotyping for uncommonly occurring isolates from humans in Brazil.

Leptospiral glycolipoprotein as a candidate antigen for serodiagnosis of human leptospirosis.

AIMS: Development of a simple, specific, rapid and inexpensive Dot-ELISA test for early diagnosis of human leptospirosis. METHODS AND RESULTS: Serum samples from 90 patients diagnosed with leptospirosis were analysed by Dot-ELISA test incorporating Glycolipoprotein (GLP) antigen from serovars Copenhageni and Patoc. Results were compared with those obtained with microscopic agglutination test, currently, the gold standard reference serological method. Serum samples from healthy blood bank donors and patients diagnosed with diseases other than leptospirosis were used as negative controls. The specificities of both GLP-based assays were 97.1% and 100% with serum samples from patients with other diseases and with serum samples from healthy control group, respectively. With serum samples from patients with acute leptospirosis, sensitivity was 76.6% with Dot-ELISA Copenhageni and 90.0% with Dot-ELISA Patoc. With serum samples from patients in convalescence, sensitivity was 100% with both GLP-based assays. CONCLUSIONS: This Dot-ELISA provides a candidate antigen for serodiagnosis of leptospirosis during all phases of illness and could be a good alternative method for the early diagnosis of leptospirosis. SIGNIFICANCE AND IMPACT OF THE STUDY: The Dot-ELISA test is simple, specific, rapid and inexpensive. It is suitable for identifying a large number of samples and, hence, reducing the death rate of patients with leptospirosis.

Application of pulsed-field gel electrophoresis for the discrimination of leptospiral isolates in Brazil.

AIMS: Leptospirosis is a public health problem worldwide. Traditionally, microscopic agglutination test (MAT) and cross-agglutinin absorption test (CAAT) are used to identify leptospires. However, these techniques are laborious and time-consuming, requiring the maintenance of a collection of more than 200 reference strains and correspondent rabbit antisera. The purpose of this study was to evaluate the pulsed-field gel electrophoresis (PFGE) method for discrimination of Leptospira serovars. METHODS AND RESULTS: Fourteen clinical isolates of Leptospira spp. were analysed by MAT before being characterized by PFGE. The isolates were compared with a library of 206 different reference Leptospira serovars. All the isolates gave clear profiles with high resolution. PFGE and MAT results were in agreement for all clinical isolates evaluated. Twelve isolates were classified as serovar Icterohaemorrhagiae/Copenhageni by PFGE. By MAT, these isolates were classified as serogroup Icterohaemorrhagiae with titres ranging from 3200 to 25 600. Two isolates were classified as serovar Canicola by PFGE, and as serogroup Canicola by MAT with titres higher than 3200. CONCLUSIONS: PFGE offers the advantages of simple, reliable and reproducible results. SIGNIFICANCE AND IMPACT OF THE STUDY: PFGE provides a convenient tool for the identification of clinical isolates.

Leptospira interrogans activation of peripheral blood monocyte glycolipoprotein demonstrated in whole blood by the release of IL-6.

Glycolipoprotein (GLP) from pathogenic serovars of Leptospira has been implicated in the pathogenesis of leptospirosis by its presence in tissues of experimental animals with leptospirosis, the inhibition of the Na,K-ATPase pump activity, and induced production of cytokines. The aims of the present study were to investigate the induction of IL-6 by GLP in peripheral blood mononuclear cells (PBMC) and to demonstrate monocyte stimulation at the cellular level in whole blood from healthy volunteers. PBMC were stimulated with increasing concentrations (5 to 2500 ng/ml) of GLP extracted from the pathogenic L. interrogans serovar Copenhageni, lipopolysaccharide (positive control) or medium (negative control), and supernatants were collected after 6, 20/24, and 48 h, and kept at -80 degrees C until use. Whole blood was diluted 1:1 in RPMI medium and cultivated for 6 h, with medium, GLP and lipopolysaccharide as described above. Monensin was added after the first hour of culture. Supernatant cytokine levels from PBMC were measured by ELISA and intracellular IL-6 was detected in monocytes in whole blood cultures by flow-cytometry. Monocytes were identified in whole blood on the basis of forward versus side scatter parameters and positive reactions with CD45 and CD14 antibodies. GLP ( > or = 50 ng/ml)-induced IL-6 levels in supernatants were detected after 6-h incubation, reaching a peak after 20/24 h. The percentage of monocytes staining for IL-6 increased with increasing GLP concentration. Thus, our findings show a GLP-induced cellular activation by demonstrating the ability of GLP to induce IL-6 and the occurrence of monocyte activation in whole blood at the cellular level.

Leptospira interrogans activation of peripheral blood monocyte glycolipoprotein demonstrated in whole blood by the release of IL-6

Glycolipoprotein (GLP) from pathogenic serovars of Leptospira has been implicated in the pathogenesis of leptospirosis by its presence in tissues of experimental animals with leptospirosis, the inhibition of the Na,K-ATPase pump activity, and induced production of cytokines. The aims of the present study were to investigate the induction of IL-6 by GLP in peripheral blood mononuclear cells (PBMC) and to demonstrate monocyte stimulation at the cellular level in whole blood from healthy volunteers. PBMC were stimulated with increasing concentrations (5 to 2500 ng/ml) of GLP extracted from the pathogenic L. interrogans serovar Copenhageni, lipopolysaccharide (positive control) or medium (negative control), and supernatants were collected after 6, 20/24, and 48 h, and kept at -80°C until use. Whole blood was diluted 1:1 in RPMI medium and cultivated for 6 h, with medium, GLP and lipopolysaccharide as described above. Monensin was added after the first hour of culture. Supernatant cytokine levels from PBMC were measured by ELISA and intracellular IL-6 was detected in monocytes in whole blood cultures by flow-cytometry. Monocytes were identified in whole blood on the basis of forward versus side scatter parameters and positive reactions with CD45 and CD14 antibodies. GLP ( > or = 50 ng/ml)-induced IL-6 levels in supernatants were detected after 6-h incubation, reaching a peak after 20/24 h. The percentage of monocytes staining for IL-6 increased with increasing GLP concentration. Thus, our findings show a GLP-induced cellular activation by demonstrating the ability of GLP to induce IL-6 and the occurrence of monocyte activation in whole blood at the cellular level.

The persistence of leptospiral agglutinins titers in human sera diagnosed by the microscopic agglutination test.

The persistence of agglutinins detected by MAT has created some problems to the interpretation of the results. The aim of this study was to examine the data of serology from 70 patients with serologically confirmed diagnosis of leptospirosis by during 3-13 months after being affected with leptospires in order to elucidate the interpretation of the persistence of agglutinins detected by MAT. Sixty-one patients sera (87.14%) had titers equal or greater than 800. Of these, two individuals maintained titers of 800 thirteen months after the onset. This study showed that only one sample of sera with high titers is not reliable to determine the time at which infection occurred.

Detection of Leptospira DNA in patients with aseptic meningitis by PCR.

Samples of cerebrospinal fluid from 103 patients with aseptic meningitis were tested by PCR for detection of leptospires, and the results were compared with those of the microscopic agglutination test (MAT) and an enzyme-linked immunosorbent assay for detection of immunoglobulin M (ELISA-IgM). Of these samples, 39.80% were positive by PCR and 8.74 and 3.88% were positive by MAT and ELISA-IgM, respectively.

Immunodiagnosis of human leptospirosis by dot-ELISA for the detection of IgM, IgG, and IgA antibodies.

A dot-ELISA was evaluated using antigen obtained from Leptospira interrogans cultures of the serovars brasiliensis, canicola, cynopteri, hebdomadis, and icterohaemorrhagiae for the detection of human IgM, IgG, and IgA. Single serum samples from 63 patients with the icterohemorrhagic form of leptospirosis in the acute phase, collected 3-14 days (mean = 7 days) after the onset of symptoms were tested. Ten patients were examined during convalescence and followed up for a period of 4-12 months. For a control group, serum samples from 10 apparently healthy individuals with no clinical or epidemiologic history of leptospirosis, and from 38 patients with nonleptospiral illnesses were used. In the acute phase, IgM antibodies were detected in 62 (98%) of 63 patients and IgG and IgA were observed in 70% and 76% of them, respectively. For the admission serum samples, the predictive value negative of the dot-ELISA was 98% for IgM, 72% for IgG, and 76% for IgA detection. All 10 patients followed-up during convalescence showed IgM antibodies up to the sixth month, decreasing to 57% by the 10th month, and persisting in only one of six patients during the 11th and 12th months of follow-up. Immunoglobulin G was detected in six patients up to the fourth month and in two of six individuals up to the end of follow-up. Immunoglobulin A was observed in all patients up to the end of the first month, decreasing progressively up to the sixth month, and was no longer detected in any patients from seventh to the 12th months of follow-up. The dot-ELISA can be used as an important laboratory screening test, especially when detecting IgM antibodies. It proved to be effective in the diagnosis of human leptospirosis, and appears to have advantages in terms of yield, time, and case of execution and low cost.

Evaluation of diagnostic tests for human leptospirosis.

The IgM-PK-ELISA, an enzyme-linked immunosorbent assay for immunoglobulin M employing a proteinase K-treated antigen, and the "Leptoteste-S" macroagglutination test were evaluated for use in a rapid serodiagnosis of human leptospirosis. The microscopic agglutination test (MAT) was used as reference. The three serological tests were applied to serum samples from patients with leptospirosis (N = 89), typhoid fever (N = 8), malaria (N = 19), syphilis (N = 20), hepatitis (N = 16) and from clinically healthy donors (N = 92). The overall results of the IgM-PK-ELISA and the "Leptoteste-S" are comparable to those of the MAT. However, both tests differed statistically from MAT in terms of the positivity of the acute-phase sera, with approximately 38% of the patients with leptospirosis being identified earlier than when MAT was used. The IgM-PK-ELISA, with 89.9% sensitivity and 97.4% specificity, could be the test of choice for those laboratories which are equipped to perform ELISA. The "Leptoteste-S", with 89.9% sensitivity and 94.8% specificity, seems to be easier to perform and the most accessible to peripheral laboratories for rapid screening of human sera. Both techniques present the important characteristic of detecting early antibodies against leptospires, thus providing a diagnosis during the early stages of the disease.

Evaluation of diagnostic tests for human leptospirosis

The IgM-PK-ELISA, an enzyme-linked immunosorbent assay for immunoglobulin M employing a proteinase K-treated antigen, and the "Leptoteste-S" macroagglutination test were evaluated for use in a rapid serodiagnosis of human leptospirosis. The microscopic agglutination test (MAT) was used as reference. The three serological tests were applied to serum samples from patients with leptospirosis (N=89), typhoid fever (N=8), malaria (N=19), syphilis (N=20), hepatitis (N=16) and from clinically healthy donors (N=92). The overall results of the IgM-PK-ELISA and the "Leptoteste-S"are comparable to those of the MAT. However, both tests differed statistically from MAT in terms of the positivity of the acute-phase sera, with approximately 38 per cent of the patients with leptospirosis being identified earlier than when MAT was used. The IgM-PK-ELISA, with 89,9 per cent sensitivity and 97,4 per cent specificity, could be the test of choice for those laboratories which are equipped to perform ELISA. The "Leptoteste-S", with 89.9 per cent sensitivity and 94.8 per cent specificity, seems to be easier to perform and the most accessible to peripheral laboratories for rapid screening of human sera. Both techniques present the important characteristic of detecting early antibodies against leptospires, thus providing a diagnosis during the early stages of the disease.

Search for agglutinating antibodies to Leptospira and Leptospira and Leptonema in horses, Sao Paulo, Brazil

Soros de 922 equinos aparentemente sadios, mantidos na Fazenda do Instituto Butantan (Säo Roque, SP) para produçäo de soros hiperimunes, foram analisados quanto à presença de anticorpos para sorovares de Leptospira interrogans e para Leptonema illini, através da reaçäo de aglutinaçäo microscópica (MA). Entre os 807 (87,5 por cento) animais positivos, 659 (81,7 por cento) reagiram com mais de um sorovar, com títulos entre 1:100 e 1:6.400, havendo predomínio de títulos baixos (<= 1:400), 84 por cento dos soros positivos reagiram com representantes do sorogrupo Icterohaemorrhagiae e 79,2 por cento com Leptonema illini. Dos 23 sorovares utilizados, apenas o tarassovi näo reagiu

[The serovars of Leptospira interrogans isolated from cases of human leptospirosis in São Paulo, Brazil]. / Sorovares de Leptospira interrogans isolados de casos de leptospirose humana em São Paulo, Brasil.

Eighteen strains of L. interrogans isolated from human cases were serotyped by the agglutinin-absorption test at Instituto Adolfo Lutz in São Paulo, Brazil. Fourteen were identified as serovar copenhageni (icterohaemorrhagiae serogroup), 2 as canicola (canicola serogroup), 1 as castellonis (Ballum serogroup) and 1 as pomona serogroup (serovar not yet defined). The frequency of serovar copenhageni in 100% of the isolates in icterohaemorrhagiae serogroup is emphasized and more studies to verify the real serovars prevalence as subsidy to the epidemiology of this infection are suggested by the authors.

[Evaluation of counterimmunoelectrophoresis with antigens of icterohaemorrhagiae and patoc serovars in the serodiagnosis of human leptospirosis]. / Avaliação da contraimunoeletroforese com antígenos dos sorovars icterohaemorrhagiae E patoc no diagnóstico sorológico da leptospirose humana.

Counterimmunoelectrophoresis (CIE) was applied on paired sera from 135 patients with leptospirosis and on 69 sera from a control group. The sera from patients were subdivided in 4 groups according to the results obtained by the Microscopic Agglutination Test (MAT). The first samples sera from 58 patients were non reagent by MAT. Six monthly samples of sera were taken from 7 patients to follow-up and to determine the level of agglutinin and precipitin antibodies present using MAT and CIE. Serovars icterohaemorrhagiae and patoc were used as antigens. Three types of antigens were compared, 1) Triton-X-100 extracted; 2) heat extracted and 3) a pool of them. The CIE using icterohaemorrhagiae derived antigens types agreed with MAT in 92.64, 92.64 and 94.11% of the leptospirosis sera. The patoc antigens types reacted with the control group in 7.24, 86.95 and 84.05% of the samples, and consequently were eliminated from the present study. The icterohaemorrhagiae CIE reaction become positive earlier than MAT negative sera, and reverted to negative earlier in the follow-up samples from the patients. The CIE was sensitive and specific, gave rapid results and was easy to perform.