Whole-genome Analysis Reveals Contrasting Relationships Among Nuclear and Mitochondrial Genomes Between Three Sympatric Bat Species

Understanding mechanisms involved in speciation can be challenging, especially when hybridization or introgression blurs species boundaries. In bats, resolving relationships of some closely related groups has proved difficult due subtle interspecific variation both in morphometrics and molecular data sets. The endemic South American Histiotus bats, currently considered a subgenus of Eptesicus, harbor unresolved phylogenetic relationships and of those is a trio consisting of two closely related species: Eptesicus (Histiotus) macrotus and Eptesicus (Histiotus) montanus, and their relationship with a third, Eptesicus (Histiotus) magellanicus. The three sympatric species bear marked resemblance to each other, but can be differentiated morphologically. Furthermore, previous studies have been unable to differentiate the species from each other at a molecular level. In order to disentangle the phylogenetic relationships of these species, we examined the differentiation patterns and evolutionary history of the three Eptesicus (H.) species at the whole-genome level. The nuclear DNA statistics between the species suggest strong gene flow and recent hybridization between E. (H.) montanus and E. (H.) macrotus, whereas E. (H.) magellanicus shows a higher degree of isolation. In contrast, mitochondrial DNA shows a closer relationship between E. (H.) magellanicus and E. (H.) montanus. Opposing patterns in mtDNA and nuclear markers are often due to differences in dispersal, and here it could be both as a result of isolation in refugia during the last glacial maximum and female philopatry and male-biased dispersal. In conclusion, this study shows the importance of both the nuclear and mitochondrial DNA in resolving phylogenetic relationships and species histories.

The Klingon batbugs: Morphological adaptations in the primitive bat bugs, Bucimex chilensis and Primicimex cavernis, including updated phylogeny of Cimicidae

The Cimicidae is a family of blood-dependent ectoparasites in which dispersion capacity is greatly associated with host movements. Bats are the ancestral and most prevalent hosts for cimicids. Cimicids have a worldwide distribution matching that of their hosts, but the global classification is incomplete, especially for species outside the most common Cimicidae taxa. In this study, we place a little-studied cimicid species, Bucimex chilensis, within a comprehensive molecular phylogeny of Cimicidae by sequencing the genomic regions of this and other closely related species. For this study, we collected B. chilensis females from Myotis chiloensis in Tierra del Fuego, 1,300 km further south than previously known southernmost distribution boundary. We also sequenced COI regions from Primicimex cavernis, a species which together with B. chilensis comprise the entire subfamily Primiciminae. Using Bayesian posterior probability and maximum-likelihood approaches, we found that B. chilensis and P. cavernis clustered close to each other in the molecular analyses, receiving support from similar morphological features, agreeing with the morphology-based taxonomic placement of the two species within the subfamily Primiciminae. We also describe a previously unrecognized morphological adaptation of the tarsal structure, which allows the austral bat ectoparasite, B. chilensis, to cling on to the pelage of its known host, the Chilean myotis (Myotis chiloensis). Through a morphological study and behavioral observation, we elucidate how this tarsal structure operates, and we hypothesize that by clinging in the host pelage, B. chilensis is able to disperse effectively to new areas despite low host density. This is a unique feature shared by P. cavernis, the only other species in Primiciminae.

New record of the rare Long-snouted Bat, Platalina genovensium Thomas, 1928 (Chiroptera, Phyllostomidae), in the Azapa valley, northern Chile

Platalina genovensium is a poorly known bat species from the west coast of Peru and Chile, considered as near threatened because of its narrow range of distribution. There are few records in Peru, and only one record in the Azapa valley, northern Chile from the year 1996. Here we report a new record for P. genovensium for the Azapa valley 19 years afterwards, confirming the presence of the species in the Arica y Parinacota region, Chile. 

First record of Histiotus laephotis (Thomas, 1916) from Chile and new distributional information for Histiotus montanus (Phillipi and Landbeck, 1861) (Chiroptera, Vespertilionidae)

We report new distributional records for

The movement ecology of the straw-colored fruit bat, Eidolon helvum, in sub-Saharan Africa assessed by stable isotope ratios

Flying foxes (Pteropodidae) are key seed dispersers on the African continent, yet their migratory behavior is largely unknown. Here, we studied the movement ecology of the straw-colored fruit bat, Eidolon helvum, and other fruit bats by analyzing stable isotope ratios in fur collected from museum specimens. In a triple-isotope approach based on samples of two ecologically similar non-migratory pteropodids, we first confirmed that a stable isotope approach is capable of delineating between geographically distinct locations in Sub-Saharan Africa. A discriminant function analysis assigned 84% of individuals correctly to their capture site. Further, we assessed how well hydrogen stable isotope ratios (δ(2)H) of fur keratin collected from non-migratory species (n = 191 individuals) records variation in δ(2)H of precipitation water in sub-Saharan Africa. Overall, we found positive, negative and no correlations within the six studied species. We then developed a reduced major axis regression equation based on individual data of non-migratory species to predict where potentially migratory E. helvum (n = 88) would come from based on their keratin δ(2)H. Across non-migratory species, δ(2)H of keratin and local water correlated positively. Based on the isoscape origin model, 22% of E. helvum were migratory, i.e. individuals had migrated over at least 250 km prior to their capture. Migratory individuals came from locations at a median distance of about 860 km from the collection site, four even from distances of at least 2,000 km. Ground-truthing of our isoscape origin model based on keratin δ(2)H of extant E. helvum (n = 76) supported a high predictive power of assigning the provenance of African flying foxes. Our study highlights that stable isotope ratios can be used to explain the migratory behavior of flying foxes, even on the isotopically relatively homogenous African continent, and with material collected by museums many decades or more than a century ago.

Ten-year surveillance of pneumococcal infections in Temuco, Chile: implications for vaccination strategies

We monitored Streptococcus pneumoniae serotypes causing invasive infections in patients admitted to one hospital in southern Chile during a 10-year period (1994 to 2004). All specimens isolated from patients with invasive S. pneumoniae infections were serotyped at the CDC in Atlanta, GA. A total of 508 isolates belonged to 58 serotypes. There were 95 infections in patients <2 years old, 33 infections in patients 2 to 4 years old, 61 infections in patients 5 to 14 years old, 66 infections in patients 15 to 44 years old, 134 infections in patients 45 to 64 years old, and 120 infections in patients >or=65 years old. The 10 serotypes isolated with the highest frequency in all groups were, in decreasing order, 1, 3, 14, 5, 19F, 6B, 7F, 12F, 23F, and 6A. The 10 most frequent isolates in children under 2 years of age were 1, 6B, 14, 19F, 5, 23F, 6A, 9V, and 7F. In patients >or=65 years old, the most common serotypes were 3, 7F, 1, 14, 19A, 23F, 19F, 35B, 4, and 5. Penicillin resistance was detected in 14 (2.7%) clinical specimens isolated since 1998, with 13 resistant strains identified since 2001. Vaccine coverage for the 7-valent conjugate vaccine was 42% for children <2 years of age. This study is important for the design of vaccines for this region and to evaluate public health measures to decrease pneumococcal infections.

Andes Hantavirus as possible cause of disease in travellers to South America

BACKGROUND

Hantaviruses in Europe and Asia cause haemorrhagic fever with renal syndrome and epidemic nephritis (mortality rate <1-15%). New strains of Hantaviruses cause Hantavirus pulmonary syndrome (HPS) from Canada to South America. Andes virus mortality rate is about 30% in Chile.

METHOD

Clinical charts of 54 patients were reviewed.

RESULTS

Inhalation of aerosolized urine, faeces or saliva of rodents is the principal cause of infection. The incubation period is between 8 and 43 days. The main prodromal symptoms are: myalgias, fever, fatigue, gastrointestinal disorders, dyspnoea, petechiae and coughing. After the 4th day pulmonary oedema, hypotension and renal failure appear. Haemorrhagic disorders may occur. The first laboratory tests presenting alterations are: haemoconcentration, leukocytosis, low platelet count <150 micro/L, and presence of immunoblasts. The treatment is supportive: mechanical ventilation, vasopressor drugs, haemofiltration or haemodialysis, and extracorporeal membrane oxygenation. There is no specific treatment for HPS. Preventive measures must be empathised.

CONCLUSION

The principal risk factors for tourists are: accommodation in abandoned or closed up facilities; failure to use indicated pathways when walking in forests; camping outside recommended areas; drinking water from natural sources and fishing in risk areas. The risk of infection for foreign tourists in Chile is low.

[Seroprevalence of antibodies against hantavirus in 10 communities of the IX Region of Chile where hantavirus infection were diagnosed]

BACKGROUND

Thirty six cases of clinical Hantavirus Cardiopulmonary Syndrome occurred in the IX Region of Chile. Most of these patients were young males, farm or timber workers, who lived near the Andes Mountain chain.

AIM

To conduct an epidemiological and serosurvey study to determine the seroprevalence of IgG antibodies against Hantavirus in the general adult population living in rural and urban areas of 10 endemic communities of the IX region of Chile.

MATERIAL AND METHODS

A total of 400 subjects were included, 40 of each community, 20 rural residents and 20 urban residents, 20 males and 20 females.

RESULTS

Seroprevalence was 7.5% in Melipeuco, 5.0% in Lonquimay, 2.5% in Curacautin, 2.5% in Pucón and 0.0% in the remaining communities. Seroprevalence was higher in rural population (2.5%) than in the urban areas (1%). All seropositive subjects worked in farms or forests and observed rodents near their homes or working places. Females were affected the same as males and no differences were observed between Chilean natives and Hispanics.

CONCLUSIONS

Prevalence of Hantavirus antibodies correlated with the geographic zone (Andes Mountain chain), overgrowth of wild rodents and exposure to rodent-infested environments.

Hantavirus pulmonary syndrome due to Andes virus in Temuco, Chile: clinical experience with 16 adults

STUDY OBJECTIVES

To describe the clinical features and laboratory abnormalities of 16 adults with confirmed Hantavirus pulmonary syndrome (HPS) due to Andes virus in Temuco, Chile.

DESIGN

A retrospective chart review abstracting clinical, radiologic, laboratory, and epidemiologic data.

SETTING

ICU of the university teaching hospital in Temuco, Chile.

PATIENTS

Sixteen patients with HPS treated between 1997 and 1999.

RESULTS

Patients were aged from 19 to 45 years, 82% were men, and 88% were farm or timber workers with occupational acquisition of HPS. After an incubation period ranging from 5 to 25 days, a prodromal influenza-like phase frequently was accompanied by abdominal symptoms. From 1 to 7 days later, respiratory insufficiency and hemodynamic instability suddenly appeared. In 81%, hemorrhage was evident; in 63%, moderate-to-severe bleeding occurred. The most prominent laboratory abnormalities were hemoconcentration, leukocytosis, thrombocytopenia, altered partial thromboplastin time (PTT), creatine kinase, transaminases, and hyponatremia. Creatinine elevation was common, with clinical importance in two patients. All patients had severe hypoxemia and pulmonary edema. Fifteen patients received supportive treatment, and 5 patients were treated with corticosteroids. The mortality rate was 43.8%.

CONCLUSIONS

Bad prognostic factors appeared to be severe hypotension, lower PaO(2)/fraction of inspired oxygen values, prolonged PTT, hemorrhage, greater volume load, and profuse bronchorrhea. The effects of treatment with corticosteroids could not be determined. Hemorrhage and renal involvement were common in our patients, features not often described in the North American literature of Sin Nombre virus HPS.

Influence of patient age on Streptococcus pneumoniae serotypes causing invasive disease

All clinical S. pneumoniae specimens isolated from patients with invasive or sterile-site infections admitted to one regional general hospital in southern Chile were collected during a 5-year period (February 1994 to September 1999). A total of 247 strains belonging to 50 serotypes were isolated in this survey: 69 in patients under 5 years of age, 129 in patients 5 to 64 years old, and 49 from patients 65 years and older. Eight serotypes were identified in all age groups, while all other serotypes were found exclusively in one age group or in patients over 4 years of age. Serotype 3 was never found in patients under 5 years old, and serotype 14 was not found in patients >64 years of age. There was no difference in the serotypes causing infection in each one of the 5 years of the survey. Our results suggest that both bacterial virulence factors and host factors play an important role in the selection of S. pneumoniae serotypes causing invasive infection. Possible host factors include age-related differences in the immune response. Comparative studies with other areas of the world may help to further understanding of our observations in southern Chile.

Additive and nonadditive genetic variability for growth traits in the Turipaná Romosinuano-Zebu multibreed herd

Intrabreed additive genetic, environmental, and phenotypic variances and covariances for Romosinuano (R) and Zebu (Z), as well as interbreed nonadditive genetic variances and covariances (sire x breed-group-of-dam interactions), for birth weight (BWT), weaning weight (WW), and postweaning gain (GW) were computed using a Romosinuano-Zebu multibreed data set from the Turipaná Experiment Station in Colombia. Covariances were estimated with a sire-maternal grandsire model, using a multibreed REML procedure. The computing algorithm was a generalized expectation-maximization (GEM) algorithm. This algorithm yields no asymptotic standard errors as part of its computations. Because of the small size of the data set (2,546 calves), these REML covariance estimates should be viewed with caution. Estimates of intrabreed heritabilities were similar to the ratios of interbreed nonadditive to phenotypic variances (interactibilities) for direct and maternal effects of the growth traits evaluated in this study. Intrabreed heritability estimates for BWT, WW, and GW direct genetic effects were .16, .09, and .14, for R and .24, .10, and .14 for Z. Corresponding heritability values for maternal effects were .18, .09, and .23 for R and .14, .13, and .07 for Z. Interactibility estimates were .21, .05, and .12, for direct and .26, .04, and .11, for maternal BWT, WW, and GW. Negative correlations between additive maternal weaning weight and direct and maternal postweaning gain, as well as between environmental weaning weight and postweaning gain, suggested that there was compensatory postweaning gain in this herd. Estimates of genetic variation and predictions of expected progeny differences showed that Romosinuano animals competed well against Zebu and RZ crossbred animals under the tropical environmental conditions at Turipaná.

Capsular serotype and antibiotic resistance of Streptococcus pneumoniae isolates in two Chilean cities

We compared the incidence of nasopharyngeal colonization by Streptococcus pneumoniae, the serotypes causing mucosal and invasive diseases, and the antibiotic resistance of these strains in patients admitted to three large hospitals and children attending day care centers in two Chilean cities (Santiago and Temuco). The populations in both cities were similar in ethnic background, socioeconomic status, family size, and access to medical care. Significant differences in nasopharyngeal colonization rates, in serotypes causing infections, and in antibiotic resistance were found between the two cities. In children 0 to 2 years of age, 42% were colonized with S. pneumoniae in Santiago compared to 14% in Temuco. A total of 41 serotypes were identified in both Chilean cities studied. Six serotypes were found only in Santiago; 14 serotypes were found only in Temuco. Antibiotic-resistant serotypes 6A, 6B, 14, 19F, and 23F were detected only in Santiago. We show that important differences in the incidence of nasopharyngeal carriage, infection, and S. pneumoniae serotypes can exist in similar populations in different areas of the same country. Our findings are relevant for prevention strategies, antibiotic usage, and vaccine design.

[Invasive extrapulmonary infections due to Streptococcus pneumoniae. Report of three fatal cases and review]

Streptococcus pneumoniae is a most important patogen in respiratory and meningeal infections. It is also a relevant agent of septic arthritis, pericarditis, acute endocarditis and spontaneous peritonitis in cirrhotic patients with ascites. It is less well known as a cause of infections in many other sites, including abdominal organs and soft tissues, which may be very severe. In this report, we describe three fatal cases (phlegmonous gastritis, cellulitis and primary peritonitis without pre-existing ascites) due to Streptococcus pneumoniae. In the last years it has become clear that this agent can cause infections at almost any body level, which is worth remembering. We review the literature and discuss some clinical aspects of two rare infectious syndromes, like primary peritonitis without previous ascites and phlegmonous gastritis.

[Immunofluorescence in the diagnosis of acute bacterial meningitis]

We evaluated immunofluorescence techniques to investigate the presence of S pneumoniae, N meningitidis, H influenzae types a and b and L monocytogenes in 85 samples of CSF fluid: 60 were taken from patients suffering meningitis and 25 from a control group. Results were compared to conventional bacteriologic methods. There were no false positive results in the control group. In patients with meningitis, 28 were positive by both methods. Nine additional patients were positive only to immunofluorescence which allowed identification of S pneumoniae in 6, N meningitidis in 2 and H influenzae in 1. 37 samples were positive by immunofluorescence and 28 of them were positive to conventional bacteriology. There was only 1 case of Group B streptococcus identified by bacteriology which was not diagnosed by immunofluorescence. Thus, immunofluorescence increases the ability to make a bacteriologic diagnosis in patients with meningitis.