Detection of Cyclomodulin CNF-1 Toxin-Producing Strains of Escherichia coli in Pig Kidneys at a Slaughterhouse.

Food is often contaminated with Escherichia coli (E. coli) bacteria strains, which have been associated with different diseases, including urinary tract infections. The consumption of meat by humans is a potential route of transmission of antimicrobial resistance, and food-producing animals have been associated as a major reservoir of resistant bacterial strains. The aim of this study was to determine the presence of the E. coli strains producing the CNF-1 toxin in pig kidneys. Pig kidneys were collected from a Mexican slaughterhouse and classified according to their coloration into reddish kidneys (RK) and yellowish kidneys (YK). A tissue sample from each kidney was processed for histological analysis, the presence of E. coli was determined by conventional PCR assay, and the CNF-1 toxin was detected by both conventional PCR and Western blotting. Herein, an inflammatory cell infiltrate was found in all collected kidneys, regardless of macroscopic differences. Surprisingly, E. coli and the CNF-1 toxin were detected in all kidney samples. We clearly demonstrate contamination by CNF-1 toxin-producing E. coli in pork kidneys from a slaughterhouse, even in those without apparent damage. This suggests that pork may serve as a reservoir for pathogens, representing an important risk to human health.

Factors affecting attendance to cervical cancer screening among women in the Paracentral Region of El Salvador: a nested study within the CAPE HPV screening program.

BACKGROUND: Cervical cancer is the third most commonly occurring cancer among women and the fourth leading cause of cancer-related deaths in women worldwide, with more than 85 % of these cases occurring in developing countries. These global disparities reflect the differences in cervical cancer screening rates between high-income and medium- and low-income countries. At 19 %, El Salvador has the lowest reported screening coverage of all Latin American countries. The purpose of this study is to identify factors affecting public sector HPV DNA-based cervical cancer screening participation in El Salvador. METHODS: This study was nested within a public sector screening program where health promoters used door-to-door outreach to recruit women aged 30-49 years to attend educational sessions about HPV screening. A subgroup of these participants was chosen randomly and questioned about demographic factors, healthcare utilization, previous cervical cancer screening, and HPV knowledge. Women then scheduled screening appointments at their public health clinics. Screening participants were adherent if they attended their scheduled appointment or rescheduled and were screened within 6 months. The association between non-adherence and demographic variables, medical history, history of cancer, sexual history, birth control methods, and screening barriers was assessed using Chi-square tests of significance and logistic regression. RESULTS: All women (n = 409) enrolled in the study scheduled HPV screening appointments, and 88 % attended. Non-adherence was associated with a higher number of lifetime partners and being under-screened-defined as not having participated in cervical cancer screening within the previous 3 years (p = 0.03 and p = 0.04, respectively); 22.8 % of participants in this study were under-screened. CONCLUSIONS: Adherence to cervical cancer screening after educational sessions was higher than expected, in part due to interactions with the community-based health promoters as well as the educational session itself. More effective recruitment methods targeted toward under-screened women are required.

Zn(2+) induces hyperpolarization by activation of a K(+) channel and increases intracellular Ca(2+) and pH in sea urchin spermatozoa.

Zinc (Zn(2+)) has been recently recognized as a crucial element for male gamete function in many species although its detailed mechanism of action is poorly understood. In sea urchin spermatozoa, Zn(2+) was reported as an essential trace ion for efficient sperm motility initiation and the acrosome reaction by modulating intracellular pH (pHi). In this study we found that submicromolar concentrations of free Zn(2+) change membrane potential (Em) and increase the concentration of intracellular Ca(2+) ([Ca(2+)]i) and cAMP in Lytechinus pictus sperm. Our results indicate that the Zn(2+) response in sperm of this species mainly involves an Em hyperpolarization caused by K(+) channel activation. The pharmacological profile of the Zn(2+)-induced hyperpolarization indicates that the cGMP-gated K(+) selective channel (tetraKCNG/CNGK), which is crucial for speract signaling, is likely a main target for Zn(2+). Considering that Zn(2+) also induces [Ca(2+)]i fluctuations, our observations suggest that Zn(2+) activates the signaling cascade of speract, except for an increase in cGMP, and facilitates sperm motility initiation upon spawning. These findings provide new insights about the role of Zn(2+) in male gamete function.

Acceptability of self-collected versus provider-collected sampling for HPV DNA testing among women in rural El Salvador.

OBJECTIVE: To determine the acceptability of self-collected versus provider-collected sampling among women participating in public sector HPV-based cervical cancer screening in El Salvador. METHODS: Two thousand women aged 30-49 years underwent self-collected and provider-collected sampling with careHPV between October 2012 and March 2013 (Qiagen, Gaithersburg, MD, USA). After sample collection, a random sample of women (n=518) were asked about their experience. Participants were questioned regarding sampling method preference, previous cervical cancer screening, HPV and cervical cancer knowledge, HPV risk factors, and demographic information. RESULTS: All 518 women approached to participate in this questionnaire study agreed and were enrolled, 27.8% (142 of 511 responding) of whom had not received cervical cancer screening within the past 3 years and were considered under-screened. Overall, 38.8% (n=201) preferred self-collection and 31.9% (n=165) preferred provider collection. Self-collection preference was associated with prior tubal ligation, HPV knowledge, future self-sampling preference, and future home-screening preference (P<0.05). Reasons for self-collection preference included privacy/embarrassment, ease, and less pain; reasons cited for provider-collection preference were result accuracy and provider knowledge/experience. CONCLUSION: Self-sampling was found to be acceptable, therefore screening programs could consider offering this option either in the clinic or at home. Self-sampling at home may increase coverage in low-resource countries and reduce the burden that screening places upon clinical infrastructure.

Functional consequences of cleavage, dissociation and exocytotic release of ZP3R, a C4BP-related protein, from the mouse sperm acrosomal matrix.

The acrosome is an exocytotic vesicle located on the apical tip of the sperm head. In addition to having different morphological regions, two biochemically distinct compartments can be defined within the acrosome: a particulate acrosomal matrix and a soluble partition. The domains within the acrosome participate in the release of acrosomal proteins from the sperm during exocytosis, depending on whether the proteins partition into either the soluble or matrix compartments of the acrosome. We have examined the mechanism of differential release by evaluating the solubilization of acrosomal matrix protein ZP3R (sp56) from mouse sperm during the course of spontaneous acrosomal exocytosis. Using indirect immunofluorescence and immunoblotting, we found that the ZP3R monomer is processed from 67,000 M(r) to 43,000 M(r) by proteases coincident with release from the acrosome. Sperm require a maturational step, termed capacitation, before they are competent for acrosomal exocytosis and the processing of ZP3R is dramatically reduced under non-capacitating conditions. The cleavage probably takes place in complement control protein domain (CCP) 6 or the bridge region between CCP6 and CCP7, which is not present in the guinea pig orthologue AM67. The cleaved form of ZP3R does not bind to unfertilized eggs. We have incorporated these structural considerations into a model to explain the functional consequences of acrosomal exocytosis on sperm-zona interactions.

Acrosomal exocytosis of mouse sperm progresses in a consistent direction in response to zona pellucida.

Sperm acrosomal exocytosis is essential for successful fertilization, and the zona pellucida (ZP) has been classically considered as the primary initiator in vivo. At present, following what is referred to as primary binding of the sperm to the ZP, the acrosome reaction paradigm posits that the outer acrosomal membrane and plasma membrane fuse at random points, releasing the contents of the acrosome. It is then assumed that the inner acrosomal membrane mediates secondary binding of the sperm to the ZP. In the present work we used a live fluorescence imaging system and mouse sperm containing enhanced green fluorescent protein (EGFP) in their acrosomes. We compared the processes of acrosomal exocytosis stimulated by the calcium ionophore ionomycin or by solubilized ZP. As monitored by the loss of EGFP from the sperm, acrosomal exocytosis driven by these two agents occurred differently. When ionomycin was used, exocytosis started randomly (no preference for the anterior, middle or posterior acrosomal regions). In contrast, following treatment with solubilized ZP, the loss of acrosomal components always started at the posterior zone of the acrosome and progressed in an anterograde direction. The exocytosis was slower when stimulated with ZP and on the order of 10 sec, which is in accordance with other reports. These results demonstrate that ZP stimulates acrosomal exocytosis in an orderly manner and suggest that a receptor-mediated event controls this process of membrane fusion and release of acrosomal components. These findings are incorporated into a model.

Extracellular adenosine 5'-triphosphate alters motility and improves the fertilizing capability of mouse sperm.

Extracellular adenosine 5'-triphosphate (ATPe) treatment of human sperm has been implicated in improving in vitro fertilization (IVF) results. We used the mouse model to investigate mechanisms of action of ATPe on sperm. ATPe treatment significantly enhanced IVF success as indicated by both rate of pronuclear formation and percentage cleavage to the 2-cell stage. However, ATPe did not increase the percentage of sperm undergoing spontaneous acrosomal exocytosis nor change the pattern of protein tyrosine phosphorylation normally observed in capacitated sperm. ATPe altered sperm motility parameters; in particular, both noncapacitated and capacitated sperm swam faster and straighter. The percentage of hyperactivated sperm did not increase in capacitated ATPe-treated sperm compared to control sperm. ATPe induced a rapid increase in the level of intracellular calcium that was inhibited by two distinct P2 purinergic receptor inhibitors, confirming that these receptors have an ionotropic role in sperm function. The observed motility changes likely explain, in part, the improved fertilizing capability when ATPe-treated sperm were used in IVF procedures and suggest a mechanism by which ATPe treatment may be beneficial for artificial reproductive techniques.