Characterization of commensal Escherichia coli isolates from slaughtered sheep in Mexico.

INTRODUCTION: Commensal Escherichia coli is defined as bacteria without known virulence factors that could be playing a specific role in some diseases; however, they could be responsible to disseminate antimicrobial resistance genes to other microorganisms. This study aimed to characterize the commensal E. coli isolates obtained from slaughtered sheep in the central region of Mexico. METHODOLOGY: Isolates were classified as commensal E. coli when distinctive genes related to diarrheagenic pathotypes (stx1, stx2, eae, bfp, LT, stp, ipaH, and aggR) were discarded by PCR. Identification of serotype, phylogenetic group, and antimicrobial resistance was also performed. RESULTS: A total of 41 isolates were characterized. The phylogenetic groups found were B1 in 37 isolates (90.2%), A in 2 (4.8%), and 1 isolate (2.4%) for C and D groups. Serotypes associated with diarrhea in humans (O104:H2 and O154:NM) and hemolytic uremic syndrome (O8:NM) were detected. Thirty-three isolates (80%) were resistant to ceftazidime, 23 (56%), to tetracycline 8 (19.5%) to ampicillin, and 1 to amikacin. Six isolates (14.6%) were multidrug-resistant. CONCLUSIONS: This study provides new information about commensal E. coli in slaughtered sheep, high percentages of resistance to antibiotics, and different profiles of antimicrobial resistance were found, their dissemination constitute a risk factor towards the consuming population.

Molecular Characterization of Trypanosoma cruzi in Infected Meccus pallidipennis in the Southern Region of the State of Mexico, Mexico.

PCR amplification and sequencing of Trypanosoma cruzi (T. cruzi) spliced-leader intergenic region of the mini-exon gene intergenic region (SL-IR) fragment was performed on intestinal tissue and fecal content DNA extracted from 19 Meccus pallidipennis (M. pallidipennis) specimens collected in the southern region of the State of Mexico. DNA sequence analysis from 49 bp T. cruzi SL-IR showed that all 19 samples corresponded to haplotype TcIa, and all of them were identical to GenBank sequence JQ028863. When extending the analysis to the whole 256 bp amplified sequence of the SL-IR, we found six sequences with a C insertion at position 10, one of which also presented a mutation (T/C) at position 54. One more sequence had an insertion (T) at position 223. Our findings suggest that two dominating TcIa clones are present in M. pallidipennis in the southern region of the State of Mexico. Interestingly, the SL-IR region of the dominating genotype was 100% identical to a circulating clone from Costa Rica present in humans, dogs, Triatoma dimidiata, and Panstrongylus rufotuberculatus. Future regional studies should explore the presence of this haplotype in humans and domestic animals.

Isolation and molecular characterization of Corynebacterium pseudotuberculosis from sheep and goats in Mexico.

The pathogenic bacteria of Corynebacterium pseudotuberculosis caused a chronic contagious infectious disease of the caseous lymphadenitis or pseudotuberculosis. Globally, isolates obtained from different injuries that affect sheep and goats, have been identified by fully or partially gene sequencing. However, in Mexico there is no complete study to identify by molecular and phylogenetic techniques the circulating isolates as well as its virulence factors. Therefore, in the present study we reported the identification of 57 isolates of C. pseudotuberculosis by bacteriological tests and the amplification of 16S rRNA, rpoB and pld genes, as well as, genes involved in virulence and pathogenicity: Fag A, Fag B, Fag C, Fag D and hsp60. Phylogenetic analysis was performed based on the partial sequence of the rpoB gene. Genes involved in virulence and pathogenicity were identified in the 98.2% of the isolates. Regarding the phylogenetic analysis, were identified the species and subspecies to which they belong of all the tested isolates. The phenotypic and genotypic characterization will allow to establish preventive and prophylactic measures aimed to the creation of effective immunogens against Corynebacterium pseudotuberculosis.

Identification and molecular characterization of Corynebacterium xerosis isolated from a sheep cutaneous abscess: first case report in Mexico.

BACKGROUND: Corynebacterium xerosis is a commensal organism found in skin and mucous membranes of humans. It is considered an unusual pathogen, and it is rarely found in human and animal clinical samples. Here we describe the isolation of C. xerosis from a 4-months-old Pelifolk lamb located in Tesistán, central western Mexico. This microorganism should be considered for differential diagnosis in cutaneous abscessed lesions in sheep, as it represents a zoonotic risk factor for human infection in sheep farms. CASE PRESENTATION: The animal exhibited a hard-consistency, 5 cm diameter abscess, without drainage, in the neck. The presumptive clinical diagnosis was caseous lymphadenitis, caused by Corynebacterium pseudotuberculosis. Samples were obtained by puncture and cultured in 8 % sheep blood agar under microaerophilic conditions. Colonies were non-haemolytic, brown-yellowish and showed microscopic and biochemical features similar to C. pseudotuberculosis, except for the urea test. A multiplex-PCR for the amplification of partial sequences of the pld, rpoB and intergenic fragment from 16S to 23S genes suggested that isolate could be C. xerosis, which was later confirmed by sequencing analysis of the rpoB gene. CONCLUSIONS: This study shows for the first time isolation and molecular characterization of C. xerosis from a clinical sample of an ovine cutaneous abscess in Mexico. This finding highlights the need for differential diagnosis of this pathogen in ovine skin abscesses, as well as epidemiological and control studies of this pathogen in sheep farms.

Distribution of lymphocytes, immunoglobulin-containing cells, macrophages, and dendritic cells in the accessory sex glands of rams experimentally infected with actinobacillus seminis / Distribuição de linfócitos, células carreadoras de imunoglobulinas, macrófagos e células dendríticas em glândulas sexuais acessórias de carneiros infectados experimentalmente com actinobacillus seminis

The distribution of cells involved in the immune response in accessory sex glands of rams experimentally infected with Actinobacillus seminis was studied. Twelve one-year old rams were experimentally infected by intraurethral (IU) (n=4) and intraepididymal (IE) (n=4) route, and four control (CON) animals were used. The animals were slaughtered 35 days post-inoculation, samples were taken from accessory sex glands, and bacteriology and histopathology tests were performed. The presence of CD4, CD8 and TCRγδ (WC1) lymphocytes, CD45RO cells, macrophages (CD14), dendritic cells (CD1b), IgA-, IgG- and IgM-containing cells (IgCC) was determined. Animals of the IE group developed clinical epididymitis. No lesions were seen in rams of the IU group; two of the intraepididymal inoculated CON developed small lesions in the epididymis. A. seminis isolates were achieved from 6:16 (37.5%) accessory sex glands in the IE group, but not in the IU and CON groups. In the CON group, IgA- and IgM- containing cells predominated in the bulbourethral glands and the disseminated prostate, and they were scarce or null in the vesicles and ampullae. A significant increase of IgA-, IgG- and IgM- containing cells was confirmed in the seminal vesicles, the ampullae and the bulbourethral glands in the IE group. In the IE and IU groups, an increase in CD4, CD8, WC1, CD45RO and CD14 was evidenced in the vesicles and ampullae. CD1b dendritic cells were present in the ampullae and vesicles with inflammatory processes. A. seminis triggered a local immune response in the IE and IU groups. These results indicate a different pattern of infiltrating immune cells in the accessory sex glands of infected A. seminis rams.

A distribuição das células envolvidas na resposta imune em glândulas sexuais acessórias de carneiros experimentalmente infectados com Actinobacillus seminis foi estudada. Doze carneiros de um ano de idade foram experimentalmente infectados via intrauretral (IU) (n=4) e via intraepididimal (IE) (n=4) e quatro animais controles (CON) foram utilizados. Os animais foram abatidos 35 dias após a inoculação, amostras foram retiradas das glândulas sexuais acessórias e testes bacteriológicos e histopatológicos foram realizados. A presença de linfócitos CD4, CD8 e TCRγδ (WC1), células CD45RO, macrófagos (CD14), células dendríticas (CD1b) e células contendo IgA, IgG and IgM (IgCC) foi determinada. Os animais do grupo IE desenvolveram epididimite clínica. Não foram visualizadas lesões nos carneiros do grupo IU, dois dos CON inoculados intraepididimalmente desenvolveram pequenas lesões no epidídimo. Isolados de A. seminis foram obtidos de 6:16 (37,5%) nas glândulas sexuais acessórias no grupo IE mas não nos grupos IU e CON. No grupo CON células contendo IgA and IgM predominaram nas glândulas bulbouretrais e na próstata e foram escassas ou ausentes nas vesículas e na ampola. Um incremento significativo de células contendo IgA, IgG and IgM foi confirmado nas vesículas seminais, na ampola e nas glândulas bulbouretrais no grupo IE. Nos grupos IE e IU foi evidenciado um aumento em CD4, CD8, WC1, CD45RO e CD14 nas vesículas e ampola. As células dendríticas CD1b estavam presentes na ampola e nas vesículas com processo inflamatório. A. seminis induziu uma resposta imune local nos grupos IE e IU. Estes resultados indicam um padrão diferente de células imunes infiltrantes nas glândulas sexuais acessórias de carneiros infectados por A. seminis.

Distribution of immune response cells in the pelvic urethra and the prepuce of rams / Distribuição de células da resposta imune na uretra pélvica e em prepúcio de carneiros

The pathogens of the reproductive system in the male can penetrate and establish by ascending route, from to the prepuce to the urethra, accessory glands, epididymis and testicles. The aim of this paper is determine the distribution and number of cells involved in the immune response in prepuce and pelvic urethra of rams, without apparent clinical alterations in testicle, epididymis and prepuce. [...] Significant differences were found in the total number of CD4, CD45RO, and WC1 lymphocytes, in CD14 macrophages, and CD1b dendritic cells, with mean values being greater in the fornix than in the urethra (p<0.05) in all cases. Only dendritic cells were found in the prepuce. No differences were found in the number of CD8 lymphocytes between both organs. The ratio between each cell type in the connective and the intraepithelial tissues and between organs was 10/1 for CD4 in the fornix (p<0.05), against 7/1 in the urethra (p<0.05), while CD8 had a 1/1 distribution in both mucosae. The WC1 ratio was 5/1 in both mucosae (p<0.05). CD45RO labeling was 19/1 in the prepuce (p<0.05) and 1/1 in the urethra. IgA-containing cells did not show differences in the total number of cells in both tissues. In the urethra, no IgG-containing cells were observed and IgM-containing cells were scarce; in contrast, both cell types were present in the prepuce, in amounts greater than in the urethra (p<0.05). IgA-, IgG-, and IgM-containing cells were located in both organs in the mucosal connective tissue. The presence of antigen-presenting cells, macrophages, and dendritic cells, as well as of lymphocytes CD4, CD8 TCR γδ (WC1), IgA-, IgG and IgM positive cells, and CD45RO cells suggests that both mucosae may behave as inductive and effector sites for the mucosal immune response.

Os patógenos do aparelho reprodutor do macho podem penetrar e se estabelecer por via ascendente, a partir do prepúcio à uretra, glándulas anexas, epidídimo e testículos. Neste trabalho foi quantificada a distribuição de algumas das células envolvidas na resposta imune, em nível de prepúcio e uretra pélvica, em quatro carneiros de um ano de idade, sem lesões aparentes no testículo, no epidídimo e no prepúcio.[...] Não foram encontradas diferenças significativas no número de linfocitos CD8 entre ambos os orgãos. A relação entre cada tipo celular no tecido conectivo e intra-epitelial e entre os diferentes órgãos, resultou para CD4 10/1 no prepúcio (p<0.05), contra 7/1 na uretra (p<0.05), entretanto os CD8 se distribuíram 1/1 em ambas as mucosas, não sendo significativa as diferenças. Os WC1 foram observados na relação 5/1 em ambas as mucosas (p<0.05). A célula CD45RO, no prepucio, foi observada de 19/1(p<0.05) e na uretra de 1/1, não sendo um resultado significativo. As CC-IgA não mostraram diferença significativa no total de células em ambos os tecidos. Na uretra não foram observadas as CC-IgG, e as CC-IgM foram escassas; em contrapartida, ambos os tipos celulares foram observadas no prepucio, em quantidades menores que na uretra (p<0.05). As CC-IgA, IgG e IgM foram observadas em ambos os tecidos conectivos da mucosa. A presença de células apresentadoras de antígenos, macrófagoss e células dendríticas, assim como de linfócitos CD4, CD8. TCR γδ (WC1), CC-IgA, IgG e IgM e células CD45RO, determinam que ambas as mucosas podem se comportar como locais de indução e promoção da resposta imune das mucosas.

Phenotypical characteristics, genetic identification, and antimicrobial sensitivity of Aeromonas species isolated from farmed rainbow trout (Onchorynchus mykiss) in Mexico.

In the present study, Aeromonas isolates from diseased and healthy farmed rainbow trout (Oncorhynchus mykiss) in Mexico, were characterized phenotypically and identified to species level by using 16S rDNA RFLP-PCR. A total of 50 isolates were included in the study and 10 Aeromonas species identified. The species A. veronii biovar sobria (22%), A. hydrophila (20%) and A. bestiarum (20%) were the most predominant. All isolates (100%) were resistant to cephalothin.

Resistance of cervical adenocarcinoma cells (HeLa) to venom from the scorpion Centruroides limpidus limpidus.

BACKGROUND: The venom of Centruroides limpidus limpidus (Cll) is a mixture of pharmacologically active principles. The most important of these are toxic proteins that interact both selectively and specifically with different cellular targets such as ion channels. Recently, anticancer properties of the venom from other scorpion species have been described. Studies in vitro have shown that scorpion venom induces cell death, inhibits proliferation and triggers the apoptotic pathway in different cancer cell lines. Herein, after treating human cervical adenocarcinoma (HeLa) cells with Cll crude venom, their cytotoxic activity and apoptosis induction were assessed. RESULTS: Cll crude venom induced cell death in normal macrophages in a dose-dependent manner. However, through viability assays, HeLa cells showed high survival rates after exposure to Cll venom. Also, Cll venom did not induce apoptosis after performing ethidium bromide/acridine orange assays, nor was there any evidence of chromatin condensation or DNA fragmentation. CONCLUSIONS: Crude Cll venom exposure was not detrimental to HeLa cell cultures. This may be partially attributable to the absence of specific HeLa cell membrane targets for molecules present in the venom of Centruroides limpidus limpidus. Although these results might discourage additional studies exploring the potential of Cll venom to treat human papilloma cervical cancer, further research is required to explore positive effects of crude Cll venom on other cancer cell lines.

Resistance of cervical adenocarcinoma cells (HeLa) to venom from the scorpion Centruroides limpidus limpidus

Background : The venom of Centruroides limpidus limpidus (Cll) is a mixture of pharmacologically active principles. The most important of these are toxic proteins that interact both selectively and specifically with different cellular targets such as ion channels. Recently, anticancer properties of the venom from other scorpion species have been described. Studies in vitro have shown that scorpion venom induces cell death, inhibits proliferation and triggers the apoptotic pathway in different cancer cell lines. Herein, after treating human cervical adenocarcinoma (HeLa) cells with Cll crude venom, their cytotoxic activity and apoptosis induction were assessed. Results : Cll crude venom induced cell death in normal macrophages in a dose-dependent manner. However, through viability assays, HeLa cells showed high survival rates after exposure to Cll venom. Also, Cll venom did not induce apoptosis after performing ethidium bromide/acridine orange assays, nor was there any evidence of chromatin condensation or DNA fragmentation. Conclusions : Crude Cll venom exposure was not detrimental to HeLa cell cultures. This may be partially attributable to the absence of specific HeLa cell membrane targets for molecules present in the venom of Centruroides limpidus limpidus. Although these results might discourage additional studies exploring the potential of Cll venom to treat human papilloma cervical cancer, further research is required to explore positive effects of crude Cll venom on other cancer cell lines.(AU)

Resistance of cervical adenocarcinoma cells (HeLa) to venom from the scorpion Centruroides limpidus limpidus

Background : The venom of Centruroides limpidus limpidus (Cll) is a mixture of pharmacologically active principles. The most important of these are toxic proteins that interact both selectively and specifically with different cellular targets such as ion channels. Recently, anticancer properties of the venom from other scorpion species have been described. Studies in vitro have shown that scorpion venom induces cell death, inhibits proliferation and triggers the apoptotic pathway in different cancer cell lines. Herein, after treating human cervical adenocarcinoma (HeLa) cells with Cll crude venom, their cytotoxic activity and apoptosis induction were assessed. Results : Cll crude venom induced cell death in normal macrophages in a dose-dependent manner. However, through viability assays, HeLa cells showed high survival rates after exposure to Cll venom. Also, Cll venom did not induce apoptosis after performing ethidium bromide/acridine orange assays, nor was there any evidence of chromatin condensation or DNA fragmentation. Conclusions : Crude Cll venom exposure was not detrimental to HeLa cell cultures. This may be partially attributable to the absence of specific HeLa cell membrane targets for molecules present in the venom of Centruroides limpidus limpidus. Although these results might discourage additional studies exploring the potential of Cll venom to treat human papilloma cervical cancer, further research is required to explore positive effects of crude Cll venom on other cancer cell lines.

Identification of Pasteurella multocida capsular types isolated from rabbits and other domestic animals in Mexico with respiratory diseases.

Pasteurella multocida is the causative agent of pasteurellosis, a major disease in most domestic animals and livestock. In this study, a total of 34 isolates of P. multocida from rabbits and other domestic animals from Mexico with respiratory diseases underwent polymerase chain reaction-based capsular typing. One sheep isolate was found to belong to capsular serogroup D, whereas the rest of the rabbit, sheep, cattle, pig, goat, and duck isolates belonged to capsular serogroup A of P. multocida. This is the first report of capsular type A in P. multocida isolates from rabbits and duck origin in Mexico.