Worsening Glycemia Increases the Odds of Intermittent but Not Persistent Staphylococcus aureus Nasal Carriage in Two Cohorts of Mexican American Adults.

Numerous host and environmental factors contribute to persistent and intermittent nasal Staphylococcus aureus carriage in humans. The effects of worsening glycemia on the odds of S. aureus intermittent and persistent nasal carriage was established in two cohorts from an adult Mexican American population living in Starr County, Texas. The anterior nares were sampled at two time points and the presence of S. aureus determined by laboratory culture and spa-typing. Persistent carriers were defined by the presence of S. aureus of the same spa-type at both time points, intermittent carriers were S. aureus-positive for 1 of 2 swabs, and noncarriers were negative for S. aureus at both time points. Diabetes status was obtained through personal interview and physical examination that included a blood draw for the determination of percent glycated hemoglobin A1c (%HbA1c), fasting plasma glucose, and other blood chemistry values. Using logistic regression and general estimating equations, the odds of persistent and intermittent nasal carriage compared to noncarriers across the glycemic spectrum was determined controlling for covariates. Increasing fasting plasma glucose and %HbA1c in the primary and replication cohort, respectively, were significantly associated with increasing odds of S. aureus intermittent, but not persistent nasal carriage. These data suggest that increasing dysglycemia is a risk factor for intermittent S. aureus nasal carriage potentially placing those with poorly controlled diabetes at an increased risk of acquiring an S. aureus infection. IMPORTANCE Factors affecting nasal S. aureus colonization have been studied primarily in the context of persistent carriage. In contrast, few studies have examined factors affecting intermittent nasal carriage with this pathogen. This study demonstrates that the odds of intermittent but not persistent nasal carriage of S. aureus significantly increases with worsening measures of dysglycemia. This is important in the context of poorly controlled diabetes since the risk of becoming colonized with one of the primary organisms associated with diabetic foot infections can lead to increased morbidity and mortality.

Mutation of Agr Is Associated with the Adaptation of Staphylococcus aureus to the Host during Chronic Osteomyelitis.

Selection pressures exerted on Staphylococcus aureus by host factors may lead to the emergence of mutants better adapted to the evolving conditions at the infection site. This study was aimed at identifying the changes that occur in S. aureus exposed to the host defense mechanisms during chronic osteomyelitis and evaluating whether these changes affect the virulence of the organism. Genome assessment of two S. aureus isolates collected 13 months apart (HU-85a and HU-85c) from a host with chronic osteomyelitis was made by whole genome sequencing. Agr functionality was assessed by qRT-PCR. Isolates were tested in a rat model of osteomyelitis and the bacterial load (CFU/tibia) and the morphometric osteomyelitic index (OI) were determined. The ability of the isolates to trigger the release of proinflammatory cytokines was determined on macrophages in culture. Persistence of S. aureus within the host resulted in an agrC frameshift mutation that likely led to the observed phenotype. The capacity to cause bone tissue damage and trigger proinflammatory cytokines by macrophages of the agr-deficient, unencapsulated derivative (HU-85c) was decreased when compared with those of the isogenic CP8-capsulated parental strain (HU-85a). By comparison, no significant differences were found in the bacterial load or the OI from rats challenged with isogenic Reynolds strains [CP5, CP8, and non-typeable (NT)], indicating that lack of CP expression alone was not likely responsible for the reduced capacity to cause tissue damage in HU-85c compared with HU-85a. The production of biofilm was significantly increased in the isogenic derivative HU-85c. Lack of agr-dependent factors makes S. aureus less virulent during chronic osteomyelitis and alteration of the agr functionality seems to permit better adaptation of S. aureus to the chronically infected host.

Genome-Wide Association Study of Staphylococcus aureus Carriage in a Community-Based Sample of Mexican-Americans in Starr County, Texas.

Staphylococcus aureus is the number one cause of hospital-acquired infections. Understanding host pathogen interactions is paramount to the development of more effective treatment and prevention strategies. Therefore, whole exome sequence and chip-based genotype data were used to conduct rare variant and genome-wide association analyses in a Mexican-American cohort from Starr County, Texas to identify genes and variants associated with S. aureus nasal carriage. Unlike most studies of S. aureus that are based on hospitalized populations, this study used a representative community sample. Two nasal swabs were collected from participants (n = 858) 11-17 days apart between October 2009 and December 2013, screened for the presence of S. aureus, and then classified as either persistent, intermittent, or non-carriers. The chip-based and exome sequence-based single variant association analyses identified 1 genome-wide significant region (KAT2B) for intermittent and 11 regions suggestively associated with persistent or intermittent S. aureus carriage. We also report top findings from gene-based burden analyses of rare functional variation. Notably, we observed marked differences between signals associated with persistent and intermittent carriage. In single variant analyses of persistent carriage, 7 of 9 genes in suggestively associated regions and all 5 top gene-based findings are associated with cell growth or tight junction integrity or are structural constituents of the cytoskeleton, suggesting that variation in genes associated with persistent carriage impact cellular integrity and morphology.

Parallel Epidemics of Community-Associated Methicillin-Resistant Staphylococcus aureus USA300 Infection in North and South America.

BACKGROUND: The community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) epidemic in the United States is attributed to the spread of the USA300 clone. An epidemic of CA-MRSA closely related to USA300 has occurred in northern South America (USA300 Latin-American variant, USA300-LV). Using phylogenomic analysis, we aimed to understand the relationships between these 2 epidemics. METHODS: We sequenced the genomes of 51 MRSA clinical isolates collected between 1999 and 2012 from the United States, Colombia, Venezuela, and Ecuador. Phylogenetic analysis was used to infer the relationships and times since the divergence of the major clades. RESULTS: Phylogenetic analyses revealed 2 dominant clades that segregated by geographical region, had a putative common ancestor in 1975, and originated in 1989, in North America, and in 1985, in South America. Emergence of these parallel epidemics coincides with the independent acquisition of the arginine catabolic mobile element (ACME) in North American isolates and a novel copper and mercury resistance (COMER) mobile element in South American isolates. CONCLUSIONS: Our results reveal the existence of 2 parallel USA300 epidemics that shared a recent common ancestor. The simultaneous rapid dissemination of these 2 epidemic clades suggests the presence of shared, potentially convergent adaptations that enhance fitness and ability to spread.

Molecular fingerprinting of Staphylococcus aureus isolated from patients with osteomyelitis in Argentina and clonal distribution of the cap5(8) genes and of other selected virulence genes.

The molecular fingerprinting of a collection of 94 Staphylococcus aureus isolates from patients with osteomyelitis in Argentina was performed. Twenty-three SmaI pulsed-field gel electrophoresis (PFGE) types and 37 spa types were identified. The isolates were assigned to 23 sequence types (STs). The proportion of methicillin-resistant S. aureus (MRSA) isolates was significantly higher among cap5 S. aureus (35/61) compared with cap8 S. aureus (8/33) isolates (p = 0.0025). Twenty-four of the 94 isolates carried the lukS-PV/lukF-PV genes, which were significantly associated to cap5 [(23/38) compared with cap8 S. aureus isolates (1/32) (p = 0.0001)]. Forty of the 94 isolates carried genes of the egc locus (seg/sei). The distribution of seg/sei genes among isolates was related to certain clones. Isolates of the four agr types were found in the S. aureus collection. Whereas agr I isolates were evenly distributed among cap5 and cap8 S. aureus isolates (32/61 and 14/33, respectively), the agr II group was composed of 29 cap5 S. aureus isolates and agr III was composed of 16 cap8 S. aureus isolates. Two clones originally associated to animals (ST 188, 7 isolates and ST 1796, 5 isolates) were associated with chronic osteomyelitis and lack of capsular polysaccharide (CP) production. Loss of CP production remains the single factor among those investigated that is associated with chronic osteomyelitis.

An assessment of the process of informed consent at the University Hospital of the West Indies.

OBJECTIVE: To assess the adequacy of the process of informed consent for surgical patients at the University Hospital of the West Indies. METHOD: The study is a prospective, cross-sectional, descriptive study. 210 patients at the University Hospital of the West Indies were interviewed using a standardised investigator-administered questionnaire, developed by the authors, after obtaining witnessed, informed consent for participation in the study. Data were analysed using SPSS V.12 for Windows. RESULTS: Of the patients, 39.4% were male. Of the surgical procedures, 68.6% were scheduled, 7.6% urgent and 23.8% emergency, 35.2% were minor and 64.8% major. Information imparted/received was acceptable in 40% of cases, good in 24% and inadequate (unacceptable) in 36% of cases. Almost all (97.6%) patients stated that they understood why an operation was planned and 93.3% thought that they had given informed consent. Most (95.2%) thought that they had free choice and made up their own mind. A quarter (25.2%) of all patients were told that it was mandatory for them to sign the form. There was a discussion of possible side effects and complications in 56.7% of patients. CONCLUSIONS: This study clearly indicates that surgical patients at the University Hospital of the West Indies feel that they have given informed consent. However, it also suggests that more information should be given to patients for consent to be truly informed.

A comparison of the frequency of antibodies to cyclic citrullinated peptides using a third generation anti-CCP assay (CCP3) in systemic sclerosis, primary biliary cirrhosis and rheumatoid arthritis.

The objective was to investigate the frequency of anti-cyclic citrullinated peptides (CCP) antibodies in systemic sclerosis (SSc) and primary biliary cirrhosis (PBC), utilizing a new "third generation" anti-CCP ELISA (anti-CCP3) kit and a conventional anti-CCP2 assay. Patients with PBC, SSc, RA, and normal controls were included in the study. Serum samples were screened for autoantibodies by indirect immunofluorescence (IIF), antibodies to CCP by a second- and third-generation ELISA, antibodies to "scleroderma" antigens (CENP B, Scl-70, PM/Scl and fibrillarin-Scl-34) by a line immunoassay (LIA), and IgM RF by ELISA. The frequency of anti-CCP2 antibodies in SSc and PBC samples was 14.8% (11/74) and 6.2% (5/80), respectively, and the frequency of anti-CCP3 antibodies in SSc was 13.5% (10/74) and in PBC was 3.7% (3/80). By comparison, in the RA group the frequency of anti-CCP3 and anti-CCP2 antibodies was 79.1% (38/48) and 77% (37/48), respectively. Anti-CCP3 ELISA had a sensitivity, specificity, and positive and negative likelihood ratios (LR) of 79% (95% confidence interval [CI] = 64-89%), 93% (95% CI = 88-96%), 11.8 (95% CI = 6.8-20.3), and 0.22 (95% CI = 0.12-0.38), respectively. By comparison, the anti-CCP2 assay had a sensitivity, specificity, and positive and negative LRs of 77% (95% CI = 62-87), 90% (95% CI = 85-94), 8.3 (95% CI = 5.2-13.2), and 0.25 (95% CI = 0.15-0.42), respectively. In patients with SSc, there was an association of anti-CCP2 antibodies with the presence of arthritis, but there was no association of anti-CCP2 or anti-CCP3 with anti-CENP B, anti-Scl 70, or RF. This study confirmed the high specificity and sensitivity of both anti-CCP assays for the diagnosis of RA. The presence of anti-CCP antibodies in SSc was only correlated with the presence of arthritis.

The changing pattern of Tinea capitis in Jamaica.

The species of dermatophyte fungi causing tinea capitis vary from country to country and may also change with time. This study was done to identify the predominant organisms causing tinea capitis in the Jamaican population. It was a retrospective study looking at all fungal culture requests to the Microbiology Department at the University Hospital of the West Indies during the period January 1, 1998 to December 31, 2002. The results showed a gradual switch from the dominance of Microsporum audouinii (61.5%) in 1998 to the dominance of Trichophyton tonsurans (85%) in 2002. The mean age was 8.6. Females constituted 55.7% of positive cases and males, 44.3%.

The changing pattern of Tinea capitis in Jamaica / El patrón cambiante de la tinea capitis en Jamaica

The species of dermatophyte fungi causing tinea capitis vary from country to country and may also change with time. This study was done to identify the predominant organisms causing tinea capitis in the Jamaican population. It was a retrospective study looking at all fungal culture requests to the Microbiology Department at the University Hospital of the West Indies during the period January 1, 1998 to December 31, 2002. The results showed a gradual switch from the dominance of Microsporum audouinii (61.5) in 1998 to the dominance of Trichophyton tonsurans (85) in 2002. The mean age was 8.6. Females constituted 55.7of positive cases and males, 44.3.

Las especies de hongos dermatofitos que causan la tinea capitis varían de país en país, y también pueden cambiar con el tiempo. Este estudio se realizó con el propósito de identificar los organismos predominantes que causan la tinea capitis en la población jamaicana. Se trata de un estudio retrospectivo que revisó todas las solicitudes de cultivos fúngicos hechas al Departamento de Microbiología del Hospital Universitario de West Indies durante el periodo del 1ero. de enero de 1998 al 31 de diciembre de 2002. Los resultados mostraron un cambio gradual del predominio de Microsporum audoinii (61.5%) en 1998 al predominio de Trichophyton tonsurans (85%) en 2002. La edad promedio fue 8.6. Las hembras constituyeron el 55.7%, y los varones el 44.3% de los casos positivos, respectivamente.

Global spread of vancomycin-resistant Enterococcus faecium from distinct nosocomial genetic complex.

Vancomycin-resistant enterococci (VRE) have caused hospital outbreaks worldwide, and the vancomycin-resistance gene (vanA) has crossed genus boundaries to methicillin-resistant Staphylococcus aureus. Spread of VRE, therefore, represents an immediate threat for patient care and creates a reservoir of mobile resistance genes for other, more virulent pathogens. Evolutionary genetics, population structure, and geographic distribution of 411 VRE and vancomycin-susceptible Enterococcus faecium isolates, recovered from human and nonhuman sources and community and hospital reservoirs in 5 continents, identified a genetic lineage of E. faecium (complex-17) that has spread globally. This lineage is characterized by 1) ampicillin resistance, 2) a pathogenicity island, and 3) an association with hospital outbreaks. Complex-17 is an example of cumulative evolutionary processes that improved the relative fitness of bacteria in hospital environments. Preventing further spread of this epidemic E. faecium subpopulation is critical, and efforts should focus on the early disclosure of ampicillin-resistant complex-17 strains.

Toxicity, bioaccumulation and tissue partitioning of dieldrin by the shrimp, Macrobrachium faustinum de Sassure, in fresh and brackish waters of Jamaica.

The 2-week no observed effect (NOEC) and lowest observed effect (LOEC) concentrations of dieldrin were determined for Macrobrachium faustinum de Sassure in fresh and brackish waters. LOEC1,10,50,95 values in fresh water were 0.001, 0.003, 0.011 and 0.058 microg l(-1), respectively, and in brackish water, 0.00006, 0.00027, 0.00165, and 0.0172 microg l(-1), respectively. The 96-hr LC10, LC50 and LC95 values were 0.029, 0.123 and 0.771 microg l(-1), respectively. It is proposed that NOEC and LOEC be redefined to take into account the percentage of individuals affected, the severity of symptoms and the recovery of poisoned individuals. Two new terms are proposed--Median Observable Effect Concentration (MOEC) for pronounced toxic symptoms in most individuals but mortality in <50%, and Pronounced Observed Effect Concentration (POEC), which inflicts mortality in >50% individuals. Bioaccumulation of dieldrin by M. faustinum from surrounding fresh and brackish waters were rapid and fairly uniform for the first 48 h when the bioconcentration equilibrium (14.4 +/- 0.42 ng g(-1) at 0.001 microg l(-1) and 42.5 +/- 1.72 ng g(-1) at 0.01 phi g l(-1)) was achieved. Relative partitioning of residues (ng g(-1) wet wt.), after 24h exposure to 0.001 microg l(-1) of dieldrin in fresh water, in the different tissues was hepatopancreas > gonads > gills > large claws > muscle and exoskeleton. Shrimp which had accumulated 10.5 +/- 0.52 ng g(-1) dieldrin in fresh and brackish water, eliminated only about 52% of the residues after eight days in uncontaminated water.

Report of ezootic Angiostronglyus cantonesis from Jamaica [ABSTRACT]

OBJECTIVE: To study the status of infection with Angiostrongylus cantonensis in wild rats and snails in Jamaica following an outbreak of eosinophilic meningitis amongst tourists. METHODS: One hundred and thirty-one Rattus rattus and 94 R norvegicus were collected, mainly from the eastern portion of Jamaica. The animals were dissected and the heart and pulmonary arteries explored to reveal A cantonensis. Similarly, several species of land snails were collected. A portion of the head/foot was excised, fragmented and placed in separate dishes of digestion fluid (0.01 percent pepsin in 0.7 percent v/v aqeous HCI). Dishes were examined for nematode larvae 4-5 hours and 24 hours post-digestion. A microscopical comparison of larvae with museum specimens confirmed identification. RESULTS: Overall, significantly more R rattus (42.7 percent) than R morvegicus (21.3 percent) were infected (x2=11.28;p<0.0001). Considering only those parishes where 15 or more rats were collected (Hanover, Manchester, St.James, St. Elizabeth, Kingston and St.Andrew, and Portland) the prevalence of rodent infections ranged from 6 to 59 percent. Of three snails and one slug species collected, only Thelidomus asper harboured A cantonensis larvae. This snail was collected from Manchester where the highest prevalence of rodent infections also occurred. CONCLUSIONS: The findings indicate that A cantonensis is present in rats and snails in Jamaica. In the context of reports (1996, 2000) of eosinophilic meningitis on the island, we recommend that public health officials, clinical parasitologists and travel medicine practitioners consider A cantonensis as a causative agent of eosinophilic meningitis in residents and travellers to Jamaica. (AU)

The effect of accidental sulphuric acid leaking on metal distributions in estuarine sediment of Patos Lagoon.

In August of 1998 the tanker BAHAMAS belonging to the Chem Oil Company containing 12,000 t of concentrated sulphuric acid, had an accident on board, after which estuarine water entered one of the compartments of the tanker, resulting in a vigorous exothermic reaction. The reaction of acid with the metallic interior hull of the ship and the accompanying heat and H2 production resulted in an imminent risk of explosion. To avoid an explosion, given the fact that neutralization was not possible, some of the cargo was discharged into the surrounding water. Neutralization was done in January 1999, after the acid concentration in the tanker had decreased and the concentrations of Fe, Cr and Ni remained elevated. Metal concentrations in bottom sediments showed significant modifications. Leached mercury migrated and redeposited downstream, reaching approximately 76 times the background values. Such an anomaly has a well expressed barrier character. The mechanism for redeposition of Hg and other metals probably followed the pattern: Downstream as a result of dilution and mixing with seawater the pH of acid-water increases, favouring adsorption and/or precipitation of metals. The leading edge of a geochemical barrier, at positions 7-9 of sampling sites (Fig. 1), is confirmed by pH variations in the water. The reestablishment of normal pH occurred after a short time due to the high buffering capacity of seawater and large natural dilution process. The concentration of metals in estuarine water during and after the accident showed insignificant anomalies.

Fate and transport of ethoprophos in the Jamaican environment.

The hydrolytic half lives of ethoprophos in distilled, river, brackish and open sea water were 25, 133, 65 and 81 days, respectively. Under laboratory conditions, volatilisation of the residues after 12 h was 1.4-3.6, 2.3-4.5 and 6.5-20.2% from a sandy loam soil with 1, 10 and 20% moisture levels, respectively. Photolysis in soil was significantly faster (P < 0.05) in direct sunlight (T1/2 of 4.7 days) than in the shade (T1/2 of 12.3 days). The microbial degradation of ethoprophos was more than two-fold faster in unsterile soil (T1/2 of 10.9 days) than in sterile soil (T1/2 of 28.8 days). The runoff of ethoprophos from unweeded plantation soil at 23 degrees slope was significantly (P = 0.015) less than at 38 degrees slope; the amounts lost after 9 weeks and 27.5 mm of rainfall were 89.4 and 91.2%, respectively, of the applied amount from the two respective slopes. In the weeded plots, 93.6 and 92.4% of the applied insecticide were lost from 23 degrees and 38 degrees slopes, respectively. Under laboratory conditions, between 67.0 and 85.1% of ethoprophos leached through the soil columns. Under field conditions, after 9 weeks and 25 mm of rainfall, only 2.8 and 2.0% residues were recovered at a depth of 10-15 cm from unweeded and weeded slopes, respectively at 23 degrees slope, and 2.2 and 1.9% from the two respective plots at 38 degrees slope.

Typhoid fever in the park: epidemiology of an outbreak at a cultural interface.

The number of reported outbreaks of typhoid fever in the United States has recently increased. Only six were reported from 1980-1989, but seven outbreaks were reported in 1990. In August 1990, health officials in Montgomery County, Maryland, were notified of two cases of typhoid fever among persons who had attended both a family picnic attended by 60 persons and a Latin Food Festival attended by 100,000 people. We obtained interviews, blood and stool cultures, and Vi serologies from attendees at and food handlers for the picnic. We defined cases as culture-confirmed or probable. Of the 60 picnic attendees, 24 (40%) had cases, of which 16 were culture confirmed. Those who ate potato salad were at increased risk of disease (17/32 vs. 6/28, relative risk [RR] = 2.5, 95% confidence interval [CI] 1.1-5.4). Picnic attendees who also attended the Latin Food Festival were not at significantly greater risk of disease than those who did not, (11/22 vs. 13/38, RR = 1.5, CI = 0.8-2.7) and we found no evidence of disease among other festival attendees. The potato salad was prepared with intensive handling and without adequate temperature control by a recent immigrant from El Salvador who was asymptomatic, did not attend the picnic, had Salmonella typhi (S. typhi) in her stool, and had elevated Vi antibodies, strongly suggestive of the carrier state. Outbreaks of typhoid fever are a threat for cosmopolitan communities. While currently available control measures are unlikely to prevent all outbreaks, thorough investigation can identify previously unrecognized carriers.

Functional somatic complaints in adolescents: relationship to negative life events, self-concept, and family characteristics.

While recurrent somatic complaints are commonly encountered in children and adolescents, occult organic disease is rarely found in patients with these complaints. Recent studies have confirmed the clinical impression that a relationship exists between functional somatic complaints and negative life events in adolescents. Our goal was to investigate additional psychosocial characteristics that may be associated with functional complaints. One hundred fifteen adolescents coming for the first time to an adolescent medicine clinic completed standard measures of negative life events, psychophysiologic symptoms, self-esteem, peer social comparison, and family functioning before an independent evaluation by a physician. Patients with functional somatic complaints (chest pain, recurrent abdominal pain, limb pain, and hyperventilation syndrome) reported significantly more negative life events, lower self-esteem, more psychophysiologic symptoms and a lower self-evaluation than did patients coming for physical examination or routine health maintenance. Functional somatic complaints in adolescents may be associated with poor psychosocial adjustment and reaction to negative life events. In addition to ruling out organic disease, physicians dealing with these patients should evaluate other areas, including stressful life events, peer relations, and self-esteem.

Improved method for production of attenuated Venezuelan equine encephalomyelitis (TC-83 strain) vaccine.

Primary chicken embryo cell cultures were evaluated a s an alternate cell system for the production of attenuated Venezuelan equine encephalomyelitis (TC-83 strain) vaccine. The TC-83 strain virus was shown to remain stable during 10 serial passages in chicken embryo cell culture with regard to plaque size and morphology, virus yield, potency, and virulence for mice and hamsters.