Maternal health-related causes of cranial neural crest cell migration dysregulation, and their common clinical effects

Neural crest cells arise during neurulation, a process that occurs during the third week of embryogenesis. These diverse cells then divide into various subtypes including cranial neural crest cells and cardiac neural crest cells. Each of these subtypes gives rise to a wide range of features throughout the fetus. While these cells are extremely diverse, they are also incredibly sensitive to their surrounding environment. Many maternal conditions affect neural crest cell division and migration, but maternal alcohol consumption and hyperglycemia due to gestational diabetes will be discussed in detail, with special attention paid to tissues that derive from cranial neural crest cells. While the initial mechanisms of the pathology vary for both of these conditions, what is remarkable is that they ultimately cause effects in similar ways. Both mechanisms lead to the creation of reactive oxygen species, which in turn trigger apoptotic pathways. Neural crest cell death causes a variety of congenital anomalies in fetuses, including craniofacial defects and cardiac outflow tract defects. Treatment options that have been researched in both conditions also vary, but are based on similar principles. Antioxidant therapies reduce the production of reactive oxygen species, thus reducing the severity of the anomalies affecting the fetus during development. Both maternal alcohol consumption and gestational diabetes are important public health concerns, and their management is of utmost priority in society. By decreasing the rates of women who consume alcohol during pregnancy, and managing gestational diabetes in those at highest risk, the rates of fetal congenital defects could be decreased

Comparative evaluation of direct plating and most probable number for enumeration of low levels of Listeria monocytogenes in naturally contaminated ice cream products

AbstractA precise and accurate method for enumeration of low level of Listeria monocytogenes in foods is critical to a variety of studies. In this study, paired comparison of most probable number (MPN) and direct plating enumeration of L. monocytogenes was conducted on a total of 1730 outbreak-associated ice cream samples that were naturally contaminated with low level of L. monocytogenes. MPN was performed on all 1730 samples. Direct plating was performed on all samples using the RAPID'L.mono (RLM) agar (1600 samples) and agar Listeria Ottaviani and Agosti (ALOA; 130 samples). Probabilistic analysis with Bayesian inference model was used to compare paired direct plating and MPN estimates of L. monocytogenes in ice cream samples because assumptions implicit in ordinary least squares (OLS) linear regression analyses were not met for such a comparison. The probabilistic analysis revealed good agreement between the MPN and direct plating estimates, and this agreement showed that the MPN schemes and direct plating schemes using ALOA or RLM evaluated in the present study were suitable for enumerating low levels of L. monocytogenes in these ice cream samples. The statistical analysis further revealed that OLS linear regression analyses of direct plating and MPN data did introduce bias that incorrectly characterized systematic differences between estimates from the two methods

Culture-independent real-time PCR reveals extensive polymicrobial infections in hospitalized diarrhoea cases in Kolkata, India

Culture-independent identification of diarrhoeal aetiological agents was performed using DNA harvested from diarrhoeal stool specimens with SYBR-Green-based real-time PCR targeting Vibrio cholerae, Vibrio parahaemolyticus, Campylobacter spp., Shigella spp. and three different pathotypes of diarrhoeagenic Escherichia coli. Conventional culture-dependent methods detected bacterial enteropathogens in 68 of 122 diarrhoeal stool specimens. Of 68 specimens, 59 (86.8%) had a single pathogen and the remaining nine (13.2%) had polymicrobial infections with multiple pathogens. Re-analysis of the 68 specimens by culture-independent real-time PCR methods showed that 25 (36.8%) specimens contained single pathogen and 43 (63.2%) specimens contained mixed infections with multiple pathogens. The prevalence of such high levels of polymicrobial infections would not have been detected without using real-time PCR. Culture-dependent analysis assigned 54 of the 122 selected archived specimens as 'no known aetiology'. However, re-analysis of these samples by real-time PCR showed the presence of single or multiple pathogens among 34 (63%) of these specimens. Estimation of relative pathogen load by real-time PCR in the stool specimens indicated that the inability of conventional culture-dependent methods to detect the pathogens was related to lower colony-forming units of the pathogen, as reflected by lower C(t) values. Detection of high levels of polymicrobial infection by real-time PCR indicates that in the settings like Kolkata and its surroundings, where cholera and other enteric diseases are endemic, the concept of one pathogen one disease might need to be re-evaluated

Interaction between Salmonella and Schistosomiasis: A Review.

The interaction between schistosomiasis and Salmonella is a particularly important issue in Africa, where dual infection by the parasite and the bacterium are likely common. In this review, the ways in which schistosomiasis affects human biology as it relates to Salmonella are described. Those who are infected by both organisms experience reduced immunological functioning, exhibit irreversible organ damage due to prolonged schistosomiasis infection, and become latent carriers of Salmonella enterica serotypes Typhi and Paratyphi and S. Typhimurium. The sequestration of the bacteria in the parasite leads to ineffective antibiotic treatment because the bacteria cannot be completely killed, and lingering infection may then lead to antimicrobial resistance. These manifestations are likely not just for those dually infected but also for those first infected with schistosomes and, later, Salmonella. More data are needed to better understand dual infection, particularly as it may impact treatment and prevention of schistosomiasis and Salmonella in sub-Saharan Africa

Molecular Subtyping and Antibiotic Resistance Analysis of \u3cem\u3eSalmonella\u3c/em\u3e Species

The genus Salmonella, comprised of 2400 serotypes, is one of the leading causes of foodborne illnesses in the US and has been used for the deliberate contamination of food. A rapid system for detection, isolation, typing and antibiotic susceptibility profiling is essential for diagnosis and source tracking in natural outbreaks or a bioterrorism event. Pure culture is essential for molecular typing and antibiotic resistance testing. The virulence and the resistance mechanisms of Salmonella are rapidly evolving and many are still unexplained. The first aim of the study was to rapidly detect and isolate Salmonella from intentionally contaminated food. The second aim was to build a DNA fingerprinting database for accurate identification of the subtype. The third objective was to study the antibiotic susceptibility patterns and the underlying mechanisms of resistance. A correlation between the DNA subtypes and antibiograms was hypothesized. An association between the resistance determinants and pathogenicity genes was expected. A total of 114 isolates including environmental and clinical sources were tested. General and selective enrichments and immunomagnetic separation (IMS) were tested for rapid detection and isolation of Salmonella from eight food groups. Isolates were subtyped by pulsed field gel electrophoresis (PFGE) and automated RiboPrinter®. Resistance to 31 drugs was tested by the Sensititre® system and integrons were identified by PCR. The association between virulence and resistance was verified by Southern hybridization. Of the three genes tested, ompF was found to be the most reliable target for identifying Salmonella subspecies I, III and IV. Detection by real time PCR after enrichment in buffered peptone water and isolation by IMS provided the fastest results. Sixty two ribotypes and 74 pulsotypes were observed for the 100 isolates subtyped. Sixty isolates were resistant to one or more antimicrobials and 12 had class-1 integrons. In conclusion, pure culture was achieved in 25 hours by IMS. Ribotyping, a comparatively rapid technique was found to be ideal for initial identification. PFGE, which was more discriminatory, was appropriate for source tracking. Contrary to the original hypothesis, no correlation between subtyping and antibiograms was observed and no association of integrons with the virulence genes tested was demonstrate

Kit for detecting Salmonella species by assaying outer membrane porin F (ompF)

The invention relates to a method of detecting the presence of Salmonella in a sample using novel oligonucleotide sequences. Also presented is a kit for putting the method into practice and novel nucleic acid sequences for ompF. The ompF gene was found to be 100% inclusive for Salmonella species and 100% exclusive for non-Salmonella species for the strains tested thus making it an excellent marker for identification of both the species of Salmonella: S. enterica and S. bongori. Two hundred and eighteen isolates belonging to Salmonella enterica (subspecies I-VI) and Salmonella bongori were examined using novel primers designed to detect the ompF gene. The target was present in all the 218 Salmonella isolates including all the subspecies of Salm. enterica and Salm. bongori. The ompF gene was absent in 180 non-Salmonella strains tested

Method for detecting Salmonella species by assaying outer membrane Porin F (ompF)

The invention relates to a method of detecting the presence of Salmonella in a sample using novel oligonucleotide sequences. Also presented is a kit for putting the method into practice and novel nucleic acid sequences for ompF. The ompF gene was found to be 100% inclusive for Salmonella species and 100% exclusive for non-Salmonella species for the strains tested thus making it an excellent marker for identification of both the species of Salmonella: S. enterica and S. bongori. Two hundred and eighteen isolates belonging to Salmonella enterica (subspecies I-VI) and Salmonella bongori were examined using novel primers designed to detect the ompF gene. The target was present in all the 218 Salmonella isolates including all the subspecies of Salm. enterica and Salm. bongori. The ompF gene was absent in 180 non-Salmonella strains tested

Kit for detecting Salmonella species by assaying outer membrane porin F (ompF)

The invention relates to a method of detecting the presence of Salmonella in a sample using novel oligonucleotide sequences. Also presented is a kit for putting the method into practice and novel nucleic acid sequences for ompF. The ompF gene was found to be 100% inclusive for Salmonella species and 100% exclusive for non-Salmonella species for the strains tested thus making it an excellent marker for identification of both the species of Salmonella: S. enterica and S. bongori. Two hundred and eighteen isolates belonging to Salmonella enterica (subspecies I-VI) and Salmonella bongori were examined using novel primers designed to detect the ompF gene. The target was present in all the 218 Salmonella isolates including all the subspecies of Salm. enterica and Salm. bongori. The ompF gene was absent in 180 non-Salmonella strains tested