Generation of acid mine drainage around the Karaerik copper mine (Espiye, Giresun, NE Turkey): implications from the bacterial population in the Acisu effluent.

The Karaerik Cu mine is a worked-out deposit with large volumes of tailings and slags which were left around the mine site without any protection. Natural feeding of these material and run-off water from the mineralised zones into the Acisu effluent causes a serious environmental degradation and creation of acid mine drainage (AMD) along its entire length. This research aims at modelling the formation of AMD with a specific attempt on the characterisation of the bacterial population in association with AMD and their role on its occurrence. Based on 16SrRNA analyses of the clones obtained from a composite water sample, the bacterial community was determined to consist of Acidithiobacillus ferrivorans, Ferrovum myxofaciens, Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans as iron-oxidising bacteria, Acidocella facilis, Acidocella aluminiidurans, Acidiphilium cryptum and Acidiphilium multivorum as iron-reducing bacteria, and Acidithiobacillus ferrivorans, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Acidiphilium cryptum as sulphur-oxidising bacteria. This association of bacteria with varying roles was interpreted as evidence of a concomitant occurrence of sulphur and iron cycles during the generation of AMD along the Acisu effluent draining the Karaerik mine.

Leptospirose bovina no Estado da Paraíba: prevalência e fatores de risco associados à ocorrência de propriedades positivas / Bovine leptospirosis in Paraíba State: prevalence and risk factors associated with the occurrence of positive herds

Foram determinadas as prevalências de propriedades positivas e de animais positivos e identificados fatores de risco associados à leptospirose em vacas no Estado da Paraíba, Nordeste do Brasil. Foram aleatoriamente selecionadas 2.317vacas com idade ≥ 24 meses, procedentes de 450propriedades. Para o diagnóstico sorológico da infecção por Leptospira spp. foi empregado o teste de soroaglutinação microscópica (SAM), utilizando-se 24 sorovares como antígenos. Uma propriedade foi considerada positiva quando apresentou pelo menos um animal soropositivo. Das 450 propriedades investigadas 398 (89,7 por cento; IC 95 por cento = 86,6-92,2 por cento) apresentaram pelo menos um animal reagente na SAM para qualquer sorovar, e 1.349 (61,1 por cento; IC por cento = 56,6-65,4 por cento) animais foram soropositivos. O sorovar Hardjo foi o mais prevalente nas propriedades e nos animais, com frequências de 58,17 por cento e 54,69 por cento, respectivamente. Propriedade ser localizada no Sertão (odds ratio = 3,20; p = 0,003), presença de animais silvestres (odds ratio =2,89; p=0,005), não resfriar o leite (odds ratio =3,83; p=0,034) e presença de pastos alagados (odds ratio =2,36; p<0,001) foram identificados como fatores de riscos associados à prevalência de propriedades positivas. Conclui-se que a leptospirose encontra-se amplamente difundida em bovinos do Estado da Paraíba, o que reforça a necessidade de intensificação de medidas de prevenção e controle, como a vacinação dos rebanhos. De acordo com os resultados da análise de fatores de risco, sugere-se que o controle sanitário antes da introdução de animais, drenagem de áreas alagadas e melhora nas condições de manejo são importantes medidas para a prevenção da infecção.

Herd-level and animal-level prevalences were determined and risk factors associated with leptospirosis were identified in cows in the State of Paraíba, Northeastern Brazil. A total of 2,317 cows with ≥ 24 months of age from 450 herds were randomly sampled. For the serological diagnosis of Leptospira spp. infection, the microscopic agglutination test (MAT) was carried out using 24 serovars as antigens. A herd was considered positive when presented at least one seropositive animal. Of the 450 investigated herds, 398 (89.7 percent; 95 percent CI = 86.6-92.2 percent) presented at least one reactant animal at MAT to any serovar, and 1,349 (61.1 percent; 95 percent CI = 56.6-65.4 percent) animals were seropositive. Serovar Hardjo was the most prevalent in herds and animals, with frequencies of 58.17 percent and 54.69 percent respectively. Location of the herd in the Sertão (odds ratio = 3.20; p=0.003), presence of wildlife (odds ratio =2.89; p=0.005), not cooling milk (odds ratio =3.83; p=0.034) and presence of flooded pastures (odds ratio =2.36; p<0.001) were identified as risk factors for herd-level prevalence. It is concluded that leptospirosis is widely spread in cattle in State of Paraíba, which reinforces the need for increased prevention and control measures, such as vaccination of herds. According to the results of risk factors analysis it is suggested that the sanitary control before the introduction of animals, drainage of wetlands and improvement in management conditions are important measures to preventing the infection.

Lymphopenia is observed regularly in the acute (leptospiraemic) phase but not the immune phase of leptospirosis.

Lymphocyte counts in patients with leptospirosis have been shown to be variable. This study retrospectively compared lymphocyte counts from the first blood samples taken following hospital presentation in patients with leptospirosis who were either (i) IgM non-reactive, (ii) IgM reactive and microscopic agglutination test (MAT) non-reactive or (iii) IgM and MAT reactive in an effort to determine whether differences in lymphocyte counts are observed in the acute and immune phase of leptospirosis. Statistical differences in lymphocyte counts were observed between the three groups. In conclusion, this study has shown that the phase of leptospiral infection may affect patient lymphocyte counts.

Real-time homogeneous assay of rapid cycle polymerase chain reaction product for identification of Leptonema illini.

Partial 16S rDNA sequences of eight Leptospira-like field isolates that reacted weakly or not at all to microscope agglutination test were found to be similar to the 16S rDNA sequence of the nonpathogen Leptonema illini-type strain 3055. Comparison of these sequences with those of Leptospira 16S rDNA sequences revealed a Leptonema species signature sequence for which a forward amplification primer was designed. This primer was used in conjunction with a bacterial-specific 16S rDNA universal reverse primer for developing a LightCycler-based rapid PCR protocol in which fluorescence emission due to the binding of SYBR green I dye to the amplified products was continuously monitored. A melting temperature (T(m)) determined from the melting curve of the amplified product immediately after PCR confirmed that the product was of Leptonema. The protocol for 24 samples consisting of 30 PCR cycles and melting curve acquisitions required 30 min to complete and agarose gel electrophoresis of the PCR products was not necessary. The method was specific as PCR products were detected from the seven Leptonema reference strains and the eight field isolates that had been previously verified as Leptonema by 16S rDNA sequencing, but not from the two representative strains from each of the eight Leptospira genospecies tested.

Isolation of a new serovar of the genus Leptonema in the family Leptospiraceae.

A leptospira-like spirochete was isolated from a lymphocyte culture from a HIV-I and HTLV-I/II-positive patient. On the basis of serological, biological and morphological characteristics of the cells of the isolated strain (strain Lisboa), we conclude that it is a member of the genus Leptonema.

Detection of Leptospiraceae by amplification of 16S ribosomal DNA.

The polymerase chain reaction (PCR) was developed to detect Leptospiraceae. Primers were used to amplify 1 631 base-pair (bp) 5'-region of 16S rDNA. Representative strains from the species, Leptospira interrogans sensu stricto, L. borgpetersenii, L. noguchii, L. santarosai, L. weilii, L. inadai, L. meyeri and the single member strain of Leptonema were amplified. In contrast, strains representing the saprophytic species. L. biflexa, L. wolbachii and L. parva were not amplified. There was no PCR product from 23 phylogenetically unrelated species of bacteria. As little as 10-1 pg of purified DNA and as few as 10-1 leptospires could be detected using the PCR analysis. Isolates of leptospires from clinical sources gave a positive PCR band, but those from surface waters did not.