Draft Genome Sequence of the Polychlorinated Biphenyl Degrader Comamonas testosteroni Strain YAZ2, Isolated from a Natural Landscape in the Tohoku Region of Japan

We report a draft genome sequence of Comamonas testosteroni strain YAZ2, a polychlorinated biphenyl (PCB) degrader that was isolated from a PCB-unpolluted environment. The assembled genome contains a single 5.4-Mb chromosome and an 87-kb plasmid. The bph gene cluster, which is involved in PCB degradation, was found on the chromosome.

Aerobic polychlorinated biphenyl-degrading bacteria isolated from the Tohoku region of Japan are not regionally endemic

In the Tohoku region of Japan, 72% of the land comprises mountain forest zones. During winter, severe climatic conditions include heavy snowfall. In such an environment, which is considered high in biodiversity, we assumed that aerobic bacteria would be diverse and would possess the ability to degrade polychlorinated biphenyls (PCBs). In this study, 78 environmental samples were collected from the Tohoku region and 56 aerobic PCB-degrading bacterial strains were isolated. They belonged to the genera Achromobacter, Rhodococcus, Pseudomonas, Stenotrophomonas, Comamonas, Pigmentiphaga, Xenophilus, Acinetobacter, and Pandoraea. Previously reported aerobic PCB-degrading bacterial strains isolated in Japan belonged to the same genera, except that the genera Acidovorax and Bacillus were not identified in the present study. In particular, the isolated Comamonas testosteroni strains YAZ2 and YU14-111 had high PCB-degrading abilities. Analysis of the sequences of the YAZ2 and YU14-111 strains showed that the gene structures of the bph operon, which encode enzymes associated with PCB degradation, were the same as those of the Acidovorax sp. KKS102 strain. Moreover, 2,3-biphenyl dioxygenase activity was responsible for the degradation characteristics of all the isolated strains. Overall, this study suggests that aerobic PCB-degrading bacteria are not specifically endemic to the Tohoku region but distributed across Japan.

Dietary Acid Load, Serum Polychlorinated Biphenyl Levels, and Mortality Following Breast Cancer in the Long Island Breast Cancer Study Project

Dietary acid load (DAL) may be associated with all-cause mortality (ACM) and breast cancer-specific mortality (BCM), and these associations may be modified by serum polychlorinated biphenyl (PCB) levels. Participants included 519 women diagnosed with first primary in situ or invasive breast cancer in 1996/1997 with available lipid-corrected PCB data. After a median of 17 years, there were 217 deaths (73 BCM). Potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores calculated from a baseline food frequency questionnaire estimated DAL. Cox regression estimated covariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between PRAL and NEAP with mortality. We evaluated effect measure modification by total serum PCB levels (>median vs. ≤median). PRAL quartile 4 versus quartile 1 was associated with an ACM HR of 1.31 (95%CI = 0.90–1.92). In the upper median of PCBs, ACM HRs were 1.43 (95%CI = 0.96–2.11) and 1.40 (95%CI = 0.94–2.07) for PRAL and NEAP upper medians, respectively. In the lower median of PCBs, the upper median of NEAP was inversely associated with BCM (HR = 0.40, 95%CI = 0.19–0.85). DAL may be associated with increased risk of all-cause mortality following breast cancer among women with high total serum PCB levels, but inversely associated with breast cancer mortality among women with low PCB levels.

Sex specific associations between in utero exposure to persistent organic pollutants and allergy-related outcomes in childhood: The Rhea Mother–Child Cohort (Crete, Greece)

Accumulating evidence suggests that in utero exposures can influence the development of the immune system. Few studies have investigated whether prenatal exposure to persistent organic pollutants (POPs) is associated with allergy-related phenotypes in childhood, nor explored sex differences. We examined the association between prenatal exposure to POPs and offspring allergic outcomes in early and mid-childhood. We included 682 mother–child pairs from the prospective birth cohort Rhea. We measured dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB) and 6 polychlorinated biphenyl (PCB) congeners in maternal first trimester serum. Parents completed the questionnaires adapted from the International Study on Asthma and Allergy in Childhood (ISAAC) for allergy-related phenotypes when their children were 4 and 6 years old. We used Poisson regression models to estimate Risk Ratios. Prenatal HCB was associated with increased risk for rhinoconjunctivitis at 6 years (RR (95% CI): 2.5; (1.3, 4.8) for a doubling in the exposure). Among girls, prenatal DDE was associated with increased risk for current wheeze, current asthma and current rhinoconjunctivitis at 4 years (RR (95%CI): 1.4 (0.8, 2.6), 1.6 (1.1, 2.4) and 1.8 (1.0, 3.3) and p-interaction = 0.035, 0.027 and 0.059, respectively), with increased risk for current rhinoconjunctivitis at 6 years (RR (95%CI): 1.7 (0.7, 3.8) and p-interaction = 0.028) and total PCBs were associated with increased risk for current eczema at 4 years (RR (95%CI): 2.1 (1.1, 4.2) and p-interaction = 0.028). In boys, prenatal DDE was associated with decreased risk for current wheeze and current asthma at 4 years. Our findings suggest that even low levels of exposure to POPs prenatally may affect the development of childhood allergy-related outcomes in a sex and age-specific manner.

Environmental contaminants and the disproportionate prevalence of type-2 diabetes mellitus among Indigenous Cree women in James Bay Quebec, Canada

Indigenous populations are disproportionately affected by type 2 diabetes (T2DM) compared to non-Indigenous people. Of importance, the prevalence of T2DM is greater amongst females than males in First Nations communities, in contrast to higher male prevalence reported in non-Indigenous Canadians. Therefore, in this study we extend our previously published work with respect to females, and the potential association between environmental exposures to organochlorine pesticides, such as dichlorodiphenyltrichloroethane (DDT), and dichlorodiphenyldichloroethylene (DDE) to explain the greater prevalence of T2DM among Indigenous females compared to males. Using data from the Multi-Community Environment-and-Health Study, Principal Component Analysis (PCA), examined 9-polychlorinated biphenyl congeners, 7-organic pesticides, and 4-metal/metalloids. Modified Poisson regression with robust error variance estimated adjusted prevalence ratios (PR) and corresponding 95% confidence intervals (95% CI), regressing prevalent T2DM on the newly derived principal components (PC), adjusting for a priori covariates, including parity. We further examined the relationship between high detection concentrations of DDT and tertials of categorized DDE exposures on T2DM among Indigenous Cree women. Among 419 female participants, 23% (n = 95) had physician-diagnosed T2DM. PCA analysis show that DDT and Lead (Pb) loaded highly on the second axis (PC-2), although in opposite directions, indicating the different exposure sources. As previously published, T2DM was significantly associated with PC-2 across adjusted models, however, after further adjusting for parity in this analysis, T2DM was no longer significantly associated with increasing PC-2 scores (PR = 0.88, 95% 0.76, 1.03). Furthermore, we found that the highest detectable levels of DDT, and tertiles of DDE were significantly associated with prevalent T2DM in the fully adjusted model (PR = 1.93, 1.17, 3.19), and (PR = 3.58, 1.10, 11.70), respectively. This cross-sectional analysis suggests organochlorines, specifically, detectable high exposure concentrations of DDT and DDE are associated with prevalent type 2 diabetes, signifying a possible important link between parity and environmental organochlorines pesticides among Indigenous Cree women.