Thanatomicrobiome in forensic medicine.

The circumstances of death and the estimation of the post-mortem interval (PMI) are often a great challenge for scientific and judicial investigators, especially when some time has elapsed since death. Several techniques are used; nevertheless, each presents its own limitations. In the quest for new techniques that are more reliable or at least complementary to those existing and sometimes less expensive, researchers have in recent years turned toward exploring the dynamics of the different microbial communities of a corpse according to their different stages of decomposition. This article summarizes the various works done in the field and shows the different sources of microorganisms in the different parts of the human corpse and their potential interest in the field of forensic medicine.

Transfusion-transmissible infections among blood donors in Bejaia, Algeria: ten years retrospective and comparative study.

INTRODUCTION: Blood transfusion saves millions of lives year around the world; it is the most important life-saving option for blood recipients. However, this act is not without risks as contaminated blood may be the source of transfusion-transmissible infections (TTI). This is a retrospective and comparative study on the prevalence of acquired human immunodeficiency syndrome, viral hepatitis B, C and syphilis in blood donors from Bejaia province (Algeria). METHODOLOGY: This study is designed to estimate the risk of TTIs among blood donors and the demographic associated factors. It was carried out in the serology laboratories of Bejaia blood transfusion center and Khalil Amrane university hospital. Data were collected from the archived results of screening tests for HBV, HCV, HIV and syphilis, mandatory for all blood donations, from January 2010 to December 2019. The association was considered statistically significant at p < 0.05. RESULTS: Among 140,168 donors from Bejaia province, 78,123 represent the urban population and 62,045 the rural population. Over 10 years, results of serological tests revealed a prevalence of 0.077%, 0.083%, 0.102%, and 0.132%, respectively for HIV, HCV, HBV, and Treponema pallidum. Trends of hepatitis B and syphilis were decreasing; however, hepatitis C was increasing. CONCLUSIONS: HIV and syphilis prevalence have been variable, with significant peaks in 2013 and 2014, respectively. Globally, the low rates reported in this study confirm the effectiveness of the preventive policy applied by the health authorities. However, among the rural population, special attention is required to stem any resurgence of hepatitis C and syphilis.

UDP-glucuronosyltransferase genetic variation in North African populations: a comparison with African and European data.

BACKGROUND: Genetic variation in glucuronosyltransferases (UGT) is crucial in drug metabolism and risk of some diseases. AIM: To examine genetic variation in UGT in North African populations. SUBJECTS AND METHODS: Allele frequencies of SNPs UGT1A424Thr, UGT1A448Val, UGT2B1585Tyr, UGT2B15523Thr and UGT2B17 CNV deletion from Morocco, Algeria, Tunisia and Libya were compared to European and Sub-Saharan populations. RESULTS: North Africans are the group with the highest genetic heterogeneity given by internal differences in the occurrence of UGT2B17 deletion, UGT1A448Val and UGT1A4 haplotypes. UGT2B15 SNPs differentiate Sub-Saharans from the rest of the populations. CONCLUSION: North African populations show a high frequency of carriers of UGT2B15523Thr, a variant linked to an increased risk of prostate cancer. High Atlas Moroccans and Algerians show low frequency of UGT2B17del, a variant associated with high concentrations of testosterone and oestradiol.

Cytochrome and sulfotransferase gene variation in north African populations.

AIM: To describe the diversity of four cytochrome and four sulfotransferase polymorphisms in six north African samples. Scarce data have been compiled for these samples despite the rich genetic background of north African populations. MATERIALS & METHODS: CYP3A4*1B, CYP3A4*17, CYP3A4*3, CYP3A5*3, SULT1A1*2, SULT1A2*2, SULT1A2*3 and SULT1E1*2 polymorphisms were explored in 556 individuals from Morocco, Algeria, Tunisia and Libya. RESULTS: Allele frequencies in our samples largely exceeded the variation ranges described for European populations, especially for CYP3A4*1B, SULT1A1*2 and SULT1A2*3. CONCLUSION: North African populations are heterogeneous, genetically diverse and show a considerable sub-Saharan African contribution for markers associated with increased risk of prostate cancer and with differential drug metabolism.

Reassessing the Evolutionary History of the 17q21 Inversion Polymorphism.

A polymorphic inversion that lies on chromosome 17q21 comprises two major haplotype families (H1 and H2) that not only differ in orientation but also in copy-number. Although the processes driving the spread of the inversion-associated lineage (H2) in humans remain unclear, a selective advantage has been proposed for one of its subtypes. Here, we genotyped a large panel of individuals from previously overlooked populations using a custom array with a unique panel of H2-specific single nucleotide polymorphisms and found a patchy distribution of H2 haplotypes in Africa, with North Africans displaying a higher frequency of inverted subtypes, when compared with Sub-Saharan groups. Interestingly, North African H2s were found to be closer to "non-African" chromosomes further supporting that these populations may have diverged more recently from groups outside Africa. Our results uncovered higher diversity within the H2 family than previously described, weakening the hypothesis of a strong selective sweep on all inverted chromosomes and suggesting a rather complex evolutionary history at this locus.

STR-based genetic structure of the Berber population of Bejaia (Northern Algeria) and its relationships to various ethnic groups.

Patterns of genetic variation in human populations have been described for decades. However, North Africa has received little attention and Algeria, in particular, is poorly studied, Here we genotyped a Berber-speaking population from Algeria using 15 short tandem repeat (STR) loci D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818 and FGA from the commercially available AmpF/STR Identifiler kit. Altogether 150 unrelated North Algerian individuals were sampled across 10 administrative regions or towns from the Bejaia Wilaya (administrative district). We found that all of the STR loci met Hardy-Weinberg equilibrium expectations, after Bonferroni correction and that the Berber-speaking population of Bejaia presented a high level of observed heterozygosity for the 15 STR system (>0.7). Genetic parameters of forensic interest such as combined power of discrimination (PD) and combined probability of exclusion (PE) showed values higher than 0.999, suggesting that this set of STRs can be used for forensic studies. Our results were also compared to those published for 42 other human populations analyzed with the same set. We found that the Bejaia sample clustered with several North African populations but that some geographically close populations, including the Berber-speaking Mozabite from Algeria were closer to Near-Eastern populations. While we were able to detect some genetic structure among samples, we found that it was not correlated to language (Berber-speaking versus Arab-speaking) or to geography (east versus west). In other words, no significant genetic differences were found between the Berber-speaking and the Arab-speaking populations of North Africa. The genetic closeness of European, North African and Near-Eastern populations suggest that North Africa should be integrated in models aiming at reconstructing the demographic history of Europe. Similarly, the genetic proximity with sub-Saharan Africa is a reminder of the links that connect all African regions.