A genomic and historical synthesis of plague in 18th century Eurasia.

Plague continued to afflict Europe for more than five centuries after the Black Death. Yet, by the 17th century, the dynamics of plague had changed, leading to its slow decline in Western Europe over the subsequent 200 y, a period for which only one genome was previously available. Using a multidisciplinary approach, combining genomic and historical data, we assembled Y. pestis genomes from nine individuals covering four Eurasian sites and placed them into an historical context within the established phylogeny. CHE1 (Chechnya, Russia, 18th century) is now the latest Second Plague Pandemic genome and the first non-European sample in the post-Black Death lineage. Its placement in the phylogeny and our synthesis point toward the existence of an extra-European reservoir feeding plague into Western Europe in multiple waves. By considering socioeconomic, ecological, and climatic factors we highlight the importance of a noneurocentric approach for the discussion on Second Plague Pandemic dynamics in Europe.

Comparative Proteomic Studies of Yersinia pestis Strains Isolated from Natural Foci in the Republic of Georgia.

Yersinia pestis, the causative agent of plague, is a highly virulent bacterium responsible for millions of human deaths throughout history. In the last decade, two natural plague foci have been described in the Republic of Georgia from which dozens of Y. pestis strains have been isolated. Analyses indicate that there are genetic differences between these strains, but it is not known if these differences are also reflected in protein expression. We chose four strains of Y. pestis (1390, 1853, 2944, and 8787) from the National Center for Disease Control and Public Health collection for proteomic studies based on neighbor-joining tree genetic analysis and geographical loci of strain origin. Proteomic expression was analyzed using two-dimensional gel electrophoresis and mass spectrometry. Select Y. pestis strains were grown under different physiological conditions and their proteomes were compared: (1) 28°C without calcium; (2) 28°C with calcium; (3) 37°C without calcium; and (4) 37°C with calcium. Candidate proteins were identified and the differences in expression of F1 antigen, tellurium-resistance protein, and outer membrane protein C, porin were validated by Western blotting. The in vitro cytotoxicity activity of these strains was also compared. The results indicate that protein expression and cytotoxic activities differ significantly among the studied strains; these differences could contribute to variations in essential physiological functions in these strains.

Human cutaneous anthrax, Georgia 2010-2012.

We assessed the occurrence of human cutaneous anthrax in Georgia during 2010--2012 by examining demographic and spatial characteristics of reported cases. Reporting increased substantially, as did clustering of cases near urban centers. Control efforts, including education about anthrax and livestock vaccination, can be directed at areas of high risk.

Evidence of local persistence of human anthrax in the country of georgia associated with environmental and anthropogenic factors.

BACKGROUND: Anthrax is a soil-borne disease caused by the bacterium Bacillus anthracis and is considered a neglected zoonosis. In the country of Georgia, recent reports have indicated an increase in the incidence of human anthrax. Identifying sub-national areas of increased risk may help direct appropriate public health control measures. The purpose of this study was to evaluate the spatial distribution of human anthrax and identify environmental/anthropogenic factors associated with persistent clusters. METHODS/FINDINGS: A database of human cutaneous anthrax in Georgia during the period 2000-2009 was constructed using a geographic information system (GIS) with case data recorded to the community location. The spatial scan statistic was used to identify persistence of human cutaneous anthrax. Risk factors related to clusters of persistence were modeled using a multivariate logistic regression. Areas of persistence were identified in the southeastern part of the country. Results indicated that the persistence of human cutaneous anthrax showed a strong positive association with soil pH and urban areas. CONCLUSIONS/SIGNIFICANCE: Anthrax represents a persistent threat to public and veterinary health in Georgia. The findings here showed that the local level heterogeneity in the persistence of human cutaneous anthrax necessitates directed interventions to mitigate the disease. High risk areas identified in this study can be targeted for public health control measures such as farmer education and livestock vaccination campaigns.

A strain of Yersinia pestis with a mutator phenotype from the Republic of Georgia.

We describe here a strain of Yersinia pestis, G1670A, which exhibits a baseline mutation rate elevated 250-fold over wild-type Y. pestis. The responsible mutation, a C to T substitution in the mutS gene, results in the transition of a highly conserved leucine at position 689 to arginine (mutS(L689R)). When the MutSL 689R protein of G1670A was expressed in a ΔmutS derivative of Y. pestis strain EV76, mutation rates observed were equivalent to those observed in G1670A, consistent with a causal association between the mutS mutation and the mutator phenotype. The observation of a mutator allele in Yersinia pestis has potential implications for the study of evolution of this and other especially dangerous pathogens.

Traditional risk factors for Helicobacter pylori infection not found among patients undergoing diagnostic upper endoscopy-Republic of Georgia, 2007-2008.

OBJECTIVES: Helicobacter pylori causes gastritis, duodenal ulcers, and gastric cancer. Although household crowding, low socioeconomic status (SES), and poor sanitation are associated with infection elsewhere, risk factors of infection in the Republic of Georgia (ROG), a country with a high prevalence rate (>70%), remain unknown. In this study we explored potential risk factors of infection among symptomatic patients in ROG. METHODS: During 2007-2008, we prospectively recruited 390 subjects with gastrointestinal symptoms referred to five tertiary care centers for diagnostic upper endoscopy. We administered a questionnaire on potential risk factors and tested patients using three diagnostic tests: gastric biopsies underwent histological evaluation and rapid urease test (CLO test), and an ELISA was used to detect IgG against H. pylori in serum. We defined a case as having two or more positive results from the three available tests. Univariate and multivariate logistic regression analyses were performed. RESULTS: Overall, 217 (56%) patients met the study case definition. Subjects diagnosed with cancer had the highest rate of H. pylori infection (62%), followed by those with gastritis (55%), and ulcer (54%). Age >30 years (adjusted odds ratio (aOR 2.6, 95% confidence interval (CI) 1.6-4.3) and residing in the capital city (aOR 0.6, 95% CI 0.4-0.9) were significantly associated with infection. CONCLUSIONS: In this large cohort with gastrointestinal symptoms, only age >30 years and living in the capital were significant factors associated with infection. Lower SES, less education, and crowding did not confer an increased risk, in contrast to the findings of previous studies. Population-based studies are needed to identify potential routes and risk factors of H. pylori infection in ROG.

Biosafety and biosecurity as essential pillars of international health security and cross-cutting elements of biological nonproliferation.

The critical aspects of biosafety, biosecurity, and biocontainment have been in the spotlight in recent years. There have also been increased international efforts to improve awareness of modern practices and concerns with regard to the safe pursuit of life sciences research, and to optimize current oversight frameworks, thereby resulting in decreased risk of terrorist/malevolent acquisition of deadly pathogens or accidental release of a biological agent, and increased safety of laboratory workers. Our purpose is to highlight how the World Health Organization's (WHO) revised International Health Regulations (IHR[2005]), the Biological Weapons Convention (BWC), and the United Nations Security Council Resolution (UNSCR) 1540 overlap in their requirements with regard to biosafety and biosecurity in order to improve the understanding of practitioners and policymakers and maximize the use of national resources employed to comply with internationally-mandated requirements. The broad range of goals of these international instruments, which are linked by the common thread of biosafety and biosecurity, highlight their significance as essential pillars of international health security and cross-cutting elements of biological nonproliferation. The current efforts of the Republic of Georgia to enhance biosafety and biosecurity in accordance with these international instruments are summarized.

Characterization of pPCP1 Plasmids in Yersinia pestis Strains Isolated from the Former Soviet Union.

Complete sequences of 9.5-kb pPCP1 plasmids in three Yersinia pestis strains from the former Soviet Union (FSU) were determined and compared with those of pPCP1 plasmids in three well-characterized, non-FSU Y. pestis strains (KIM, CO92, and 91001). Two of the FSU plasmids were from strains C2614 and C2944, isolated from plague foci in Russia, and one plasmid was from strain C790 from Kyrgyzstan. Sequence analyses identified four sequence types among the six plasmids. The pPCP1 plasmids in the FSU strains were most genetically related to the pPCP1 plasmid in the KIM strain and least related to the pPCP1 plasmid in Y. pestis 91001. The FSU strains generally had larger pPCP1 plasmid copy numbers compared to strain CO92. Expression of the plasmid's pla gene was significantly (P ≤ .05) higher in strain C2944 than in strain CO92. Given pla's role in Y. pestis virulence, this difference may have important implications for the strain's virulence.

Genetic background and antibiotic resistance of Staphylococcus aureus strains isolated in the Republic of Georgia.

The genetic composition and antibiotic sensitivities of 50 clinical isolates of Staphylococcus aureus obtained from various clinics in the Republic of Georgia were characterized. S. aureus strains ATCC 700699 and ATCC 29737 were included as reference standards in all analyses. All 52 strains had identical 16S rRNA profiles. In contrast, pulsed-field gel electrophoresis (PFGE) identified 20 distinct PFGE types among the 52 strains examined, which indicates that PFGE is more discriminating than is 16S rRNA sequence analysis for differentiating S. aureus strains. The results of our PFGE typing also suggest that multiple genetic subpopulations (related at the ca. 85% similarity level, based on their SmaI PFGE patterns) exist among the Georgian S. aureus strains. Twenty-two of the 50 Georgian strains were methicillin resistant and PCR positive for mecA, and 5 strains were methicillin sensitive even though they possessed mecA. None of the strains were vancomycin resistant or contained vanA. The nucleotide sequences of mecA fragments obtained from all mecA-containing strains were identical. Our data indicate that the population of S. aureus strains in Georgia is fairly homogeneous and that the prevalence of methicillin-resistant, mecA-positive strains is relatively high in that country.