A scoping review of the distribution and frequency of extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae in shrimp and salmon.

Antimicrobial-resistant (AMR) bacteria are a threat to public health as they can resist treatment and pass along genetic material that allows other bacteria to become drug-resistant. To assess foodborne AMR risk, the Codex Guidelines for Risk Analysis of Foodborne AMR provide a framework for risk profiles and risk assessments. Several elements of a risk profile may benefit from a scoping review (ScR). To contribute to a larger risk profile structured according to the Codex Guidelines, our objective was to conduct a ScR of the current state of knowledge on the distribution, frequency and concentrations of extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae in salmon and shrimp. Articles were identified via a comprehensive search of five bibliographic databases. Two reviewers screened titles and abstracts for relevance and characterised full-text articles with screening forms developed a priori. Sixteen relevant studies were identified. This review found that there is a lack of Canadian data regarding ESBL-producing Enterobacteriaceae in salmon and shrimp. However, ESBL- producing Escherichia coli, Klebsiella pneumoniae and other Enterobacteriaceae have been isolated in multiple regions with a history of exporting seafood to Canada. The literature described herein will support future decision-making on this issue as research/surveillance and subsequent assessments are currently lacking.

Characterisation of burden of illness measures associated with human (Fluoro)quinolone-resistant Campylobacter spp. infections - a scoping review.

Campylobacter spp. are one of the most common causes of bacterial gastroenteritis in Canada and worldwide. Fluoroquinolones are often used to treat complicated human campylobacteriosis and strains of Campylobacter spp. resistant to these drugs are emerging along the food chain. A scoping review was conducted to summarise how human (fluoro)quinolone-resistant (FQR; quinolones including fluoroquinolones) Campylobacter spp. infections are characterised in the literature by describing how burden of illness (BOI) associated with FQR is measured and reported, describing the variability in reporting of study characteristics, and providing a narrative review of literature that compare BOI measures of FQR Campylobacter spp. infections to those with susceptible infections. The review identified 26 studies that yielded many case reports, a lack of recent literature and a lack of Canadian data. Studies reported 26 different BOI measures and the most common were hospitalisation, diarrhoea, fever and duration of illness. There were mixed results as BOI measures reported in literature were inconsistently defined and there were limited comparisons between resistant and susceptible infections. This presents a challenge when attempting to assess the magnitude of the BOI due to FQR Campylobacter spp., highlighting the need for more research in this area.

Evaluation of the health and healthcare system burden due to antimicrobial-resistant Escherichia coli infections in humans: a systematic review and meta-analysis.

BACKGROUND: Assessment of the burden of disease due to antimicrobial-resistant Escherichia coli infections facilitates understanding the scale of the problem and potential impacts, and comparison to other diseases, which allows prioritization of research, surveillance, and funding. Using systematic review and meta-analysis methodology, the objectives were to evaluate whether humans with antimicrobial-resistant E. coli infections experience increases in measures of health or healthcare system burden when compared to susceptible E. coli infections. METHODS: Comprehensive literature searches were performed in four primary and seven grey literature databases. Analytic observational studies of human E. coli infections that assessed the impact of resistance to third/fourth/fifth-generation cephalosporins, resistance to quinolones, and/or multidrug resistance on mortality, treatment failure, length of hospital stay and/or healthcare costs were included. Two researchers independently performed screening, data extraction, and risk of bias assessment. When possible, random effect meta-analyses followed by assessment of the confidence in the cumulative evidence were performed for mortality and length of hospital stay outcomes, and narrative syntheses were performed for treatment failure and healthcare costs. RESULTS: Literature searches identified 14,759 de-duplicated records and 76 articles were included. Based on 30-day and all-cause mortality meta-analyses, regardless of the type of resistance, there was a significant increase in the odds of dying with resistant E. coli infections compared to susceptible infections. A summary mean difference was not presented for total length of hospital stay meta-analyses due to substantial to considerable heterogeneity. Since small numbers of studies contributed to meta-analyses for bacterium-attributable mortality and post-infection length of hospital stay, the summary results should be considered with caution. Studies contributing results for treatment failure and healthcare costs had considerable variability in definitions and reporting. CONCLUSIONS: Overall, resistant E. coli infections were associated with significant 30-day and all-cause mortality burden. More research and/or improved reporting are necessary to facilitate quantitative syntheses of bacterium-attributable mortality, length of hospital stay, and hospital costs. Protocol Registration PROSPERO CRD42018111197.

Efficacy of pneumococcal vaccination in adults. A meta-analysis of randomized controlled trials.

BACKGROUND: Because of the prevalence of pneumococcal pneumonia, the substantial morbidity and mortality associated with many pneumococcal infections, and an increase in the incidence of antibiotic resistance among pneumococcal isolates, considerable efforts for disease prevention have been made using a polyvalent polysaccharide pneumococcal vaccine. Despite numerous clinical trials of the vaccine, its efficacy in the prevention of pneumococcal infections and other clinically relevant medical outcomes in adults remains uncertain. METHODS: To assess quantitatively the efficacy of pneumococcal vaccination, a MEDLINE literature search, manual reviews of article bibliographies, and communications with pneumococcal vaccine investigators were used to identify randomized controlled trials of the pneumococcal vaccine. Independent review of 594 articles revealed nine randomized trials with 12 vaccine and control study groups that evaluated clinically relevant outcomes in adults. To estimate a summary effect size for all outcomes, Mantel-Haenszel odds ratios (ORs) and Dersimonian and Laird rate differences (RDs) and their associated 95% confidence intervals (CIs) were computed. RESULTS: Summary ORs demonstrated a statistically significant protective effect of the vaccine for four pneumococcal infection-related outcomes: definitive pneumococcal pneumonia (OR = 0.34; 95% CI = 0.24 to 0.48), definitive pneumococcal pneumonia for vaccine-containing pneumococcal antigen types only (vaccine types only) (OR = 0.17; 95% CI = 0.09 to 0.33), presumptive pneumococcal pneumonia (OR = 0.47; 95% CI = 0.35 to 0.63), and presumptive pneumococcal pneumonia (vaccine types only) (OR = 0.39; 95% CI = 0.26 to 0.59). The summary RDs, which account for heterogeneity among studies, confirmed a statistically significant protective effect for two of these same outcomes: definitive pneumococcal pneumonia (RD = 4/1000; 95% CI = 0/1000 to 7/1000) and definitive pneumococcal pneumonia (vaccine types only) (RD = 8/1000; 95% CI = 1/1000 to 16/1000). Summary ORs and RDs failed to demonstrate a protective effect for pneumonia (all causes), bronchitis, and mortality (all causes) or mortality due to pneumonia or pneumococcal infection. Subgroup analyses showed that for all four pneumococcal infection-related outcomes, vaccine efficacy differed for high- and low-risk subjects, demonstrating efficacy for low-risk subjects and lack of efficacy for high-risk subjects. CONCLUSIONS: Pneumococcal vaccination appears efficacious in reducing bacteremic pneumococcal pneumonia in low-risk adults. However, evidence from randomized controlled trials fails to demonstrate vaccine efficacy for pneumococcal infection-related or other medical outcomes in the heterogeneous group of subjects currently labeled as high risk.

Impact of immunosuppression on health care use by men in the Multicenter AIDS Cohort Study (MACS).

The effects of human immunodeficiency virus type 1 (HIV-1) serostatus, AIDS, and level of immunosuppression on health service use were examined in the Multicenter AIDS Cohort Study. Data on self-reported hospitalizations, outpatient medical services (non-emergency room) and emergency room care during the preceding 6 months were collected for 3,447 homosexual/bisexual men returning for their 14th and/or 15th semiannual visits in Chicago, Baltimore, Los Angeles, and Pittsburgh. AIDS-free seropositive men with CD4+ cells < 200/microliters were more likely to be hospitalized [odds ratio (OR) = 2.3, 95% confidence limits (CL) = 1.4, 3.8] and use outpatient medical care (OR = 7.9, 95% CL = 4.9, 12.6), compared with seronegative men. Increased outpatient care was initiated at the earliest stages of HIV-1 infection, even when CD4+ cells were > 500/microliter. Dramatic increases in outpatient care for each level of immunosuppression were observed. HIV-1-related symptoms were associated with increased hospitalizations (OR = 4.8, 95% CL = 3.2, 7.3), use of outpatient medical services (OR = 3.3, 95% CL = 1.9, 5.6), and emergency room care (OR = 3.1, 95% CL = 2.1, 4.6). Persons with AIDS and < or = 50 CD4+ cells/microliter most likely to be hospitalized (OR = 8.1; 95% CL = 4.4, 14.9). No significant difference (p > 0.05) in emergency room use was observed according to HIV-1 serostatus, AIDS, or immunosuppression, after adjusting for insurance and clinical symptoms. To the extent that CD4+ cell counts are used as one of the criteria for an AIDS diagnosis and such a diagnosis broadens available benefits to persons with HIV disease, the pattern of health care services described here will be important for health care providers and planners.

Immunogenicity of recombinant Babesia microti hsp70 homologue in mice.

A Babesia microti hsp70 homologue was cloned, expressed in a prokaryotic system and tested in a pilot study for protection against lethal challenge. Results showed that 30% of the mice inoculated with recombinant protein (rBm hsp70) survived challenge, while all of the controls died. Evidence of antibody response to the hsp homologue was detected by Western blot analysis, but no protection was imparted through passive transfer of convalescent serum. Passively transferred spleen cells, from mice which survived challenge, also failed to impart protection. The mechanism of partial immunity suggested by these observations remains to be elucidated.

Coffee consumption: relationship to blood lipids in middle-aged women.

BACKGROUND: There is controversy about the relationship between coffee intake and blood lipids in women and many studies fail to control for potential confounding factors. METHODS: In 1983 and 1984, 541 randomly selected premenopausal women were recruited from a list of licenced drivers, aged 42-50, within selected areas in Allegheny County, Pennsylvania. They were invited to participate in a 5-year study of biological and behavioural changes associated with menopause. At baseline and the first follow-up visit, lipoprotein, lipid and apoprotein levels, physical activity, dietary intake and coffee consumption were measured. Pearson correlations between coffee consumption and the various lipid values were calculated. Multivariate analyses, which controlled for the potential confounding effects of body mass index, alcohol intake, percent of calories from carbohydrate and fat, number of cigarettes smoked per day, physical activity level, and age in months, were also employed to investigate the relationships. RESULTS: Mean coffee consumption for the group was 3.35 cups of coffee per day at baseline and 3.02 cups per day at follow-up. Results of analyses of correlation between coffee consumption and blood lipids as well as multiple regressions to control for menopausal status at follow-up were non-significant (P > 0.05) for all blood lipid values with the exception of triglycerides, which were inversely related to coffee consumption at follow-up. CONCLUSIONS: These results do not support a relationship between coffee consumption and lipoprotein, lipid or apoprotein levels with the exception of an inverse relationship between coffee consumption and triglyceride level at follow-up.

Excimer laser treatment for high and extreme myopia. The Melbourne Excimer Laser and Research Group.

OBJECTIVE: The excimer laser allows the controlled ablation of corneal tissue to correct refractive error. We assessed the efficacy of excimer laser treatment for persons with high (spherical equivalent between -5 and -10 diopters) and extreme (spherical equivalent greater than -10D) myopia. METHODS: Patients were assessed 1, 3, and 6 months postoperatively. A VisX Twenty/Twenty laser was used. Visual acuity, refraction, corneal clarity, and adverse reactions were evaluated at each visit. RESULTS: Six month follow-up data were available for 194 high myopes and 53 extreme myopes. Postoperative healing was similar for the two groups. Six months postoperatively, 89.2% of high myopes and 49% of extreme myopes were within 2D of planned refraction. At 6 months, 28% of high myopes had an uncorrected visual acuity of 20/20 and 71% had an uncorrected visual acuity of 20/40. Of extreme myopes, 4% had an uncorrected visual acuity of 20/20 and 30% had an uncorrected visual acuity of 20/40. Significantly more corneal haze was observed in the extreme myopes. Loss of 2 or more lines of best corrected visual acuity was observed in 13% of high myopes and 13% of extreme myopes at 6 months. CONCLUSIONS: Excimer laser photorefractive keratectomy is an alternative means of treating high and extreme myopia and can cause a significant reduction in myopia. There is a need to gather further information as more patients are followed up for greater time.

One-year evaluation of excimer laser photorefractive keratectomy for myopia and myopic astigmatism. Melbourne Excimer Laser Group.

OBJECTIVE: To evaluate prospectively the efficacy and safety of excimer laser photorefractive keratectomy in the treatment of myopia and myopic astigmatism. METHODS: Up to 15 diopters (D) of myopia with or without astigmatism of less than 6 D was treated with an excimer laser (VISX Twenty/Twenty). One hundred fifty procedures have been followed up for more than 12 months. RESULTS: Postoperative refractions were generally stable after 3 months without significant early overcorrection. Of those eyes treated with spherical equivalents of 5 D or less, 96% were within 1 D of the targeted refraction after photorefractive keratectomy and 88% had uncorrected visual acuities of 20/40 or better. At 12 months, 77% of all 150 eyes treated achieved an uncorrected visual acuity of 20/40 or better and 81% were within 1 D of the intended correction. Nine eyes (6%) lost 2 or more lines of best corrected visual acuity and 14 (9%) gained 2 or more lines. Adverse reactions were reported in 12 patients (8%) during the postoperative period. CONCLUSIONS: Photorefractive keratectomy is capable of correcting low and moderate myopic errors with a relatively high degree of accuracy and safety. The predictability and stability of the postoperative refraction during the first 12 months seem to be good.

Growth of Babesia bovis in bovine erythrocyte cultures.

Babesia bovis was cultured in a suspension of bovine erythrocytes incubated at 37 degrees C in Medium 199 with 50% bovine serum. The cells in culture were kept in suspension by slow stirring in spinner flasks and the medium was replaced at 24-hour intervals. Persistent multiplication of the parasite in a short series of subcultures suggests the feasibility of this approach for continuous culture.

Prevalence of central islands after excimer laser refractive surgery.

We conducted a study to determine the prevalence of central islands after refractive excimer laser surgery and the factors associated with their occurrence. A VISX Twenty/Twenty excimer laser was used to perform 157 photorefractive keratectomy (PRK) and 263 photorefractive astigmatic keratectomy (PARK) procedures. Corneal topography was assessed in 156 patients three months postoperatively using a topographic analysis system. Central islands were seen in 67% of patients; 26% had islands of 3.0 diopters (D) or more in height. Occurrence was associated with the laser suction nozzle being fixed during the procedure (P < .05). There was no demonstrable effect of central islands on visual acuity or refractive outcome, nor was there any relation to the amount of attempted correction or type of procedure (PARK or PRK). Central islands with a curvature difference of less than 3.0 D were seen more frequently than an absence of islands, suggesting these may be a "normal" postoperative topographic variation. The effect of nozzle position on island formation suggests that plume removal or corneal hydration may be important, as is corneal epithelial healing.

The epidemiology of cataract: a review of the literature.

Cataract is a major cause of blindness, accounting for nearly half of all blindness worldwide. Epidemiological research provides the principles and methods to assess the extent of cataract, and supplies the necessary information for policy planning. Obtaining accurate epidemiological data on cataract is essential to ascertain and estimate the cost of primary and secondary eye health care needs. Determining risk factors is also necessary to reduce the economic and social repercussions associated with the disease. The following paper presents a review of the epidemiology of cataract in the middle to elderly age group.

Fastpac visual field screening.

In epidemiology, screening for visual field defects has traditionally been expensive, time consuming and laborious. To achieve cost- and time-effective visual field screening, a faster algorithm has been developed for the Humphrey perimeter called Fastpac, which is designed to achieve threshold perimetry in two-thirds the time of the standard algorithm. We compared the Fastpac and conventional full-threshold 24-2 fields obtained in 39 eyes of 36 participants. We divided the participants' fields into normal (14) and glaucomatous (25) visual field groups, and compared the test times, number of questions asked and statistical parameters generated for each field for Fastpac as compared to the standard algorithm. Then we divided the participants' fields into Fastpac and standard fields and again compared the test times, number of questions and statistical parameters. Finally we asked trained observers to judge the fields as being normal or abnormal, in a masked fashion, and found a high degree of agreement between the fields generated by Fastpac and standard. Fastpac offers accurate full-threshold screening in two-thirds the time of the conventional algorithm and would be very useful for large scale prevalence studies in ophthalmic epidemiology.

Methods for a population-based study of eye disease: the Melbourne Visual Impairment Project.

The methodology of the Melbourne Visual Impairment Project, a major population-based survey of eye disease on 3,500 randomly selected individuals aged 40 years of age and over in the Melbourne metropolitan region, is presented. The aims of the study are to determine the distribution and determinants of eye disease in an urban population; the impact of eye disease on visual function and the activities of daily living; and the accessibility of eye health care services in the community. All procedures are conducted according to a standardised protocol to allow for comparison with other population-based studies, both in Australia and overseas. Information collected from this study will be employed in the development of recommendations related to eye health care service delivery and establishment of priorities for future public education programmes and health research.

Health status indicators for the year 2000: projections for Allegheny County, Pennsylvania.

A consensus set of health status indicators was released in July 1991 by the Centers for Disease Control and Prevention for use by public health officials at the Federal, State, and local levels in identifying and monitoring issues of public health importance. These health status indicators have been projected for the Year 2000 in Allegheny County, PA, with linear regression analyses of historical data. Indications are that mortality rates for black infants, breast cancer mortality, suicide, lung cancer mortality, incidence of acquired immunodeficiency syndrome, and the number of measles cases likely will not meet the year 2000 targets in Allegheny County. These data will prove useful in monitoring progress towards the year 2000 objectives and provide comparative data for other geographic areas of the United States with similar demographic characteristics.

Cloning of in vitro propagated Babesia bigemina.

The original Babesia bigemina culture conditions were modified with regard to infected bovine erythrocyte concentration and atmospheric environment. A procedure was designed which would yield a homogeneous parasite population, beginning with a single infected erythrocyte. Calculated dilutions were made in 96-well tissue culture plates to approach one infected erythrocyte per four wells. Growth of parasites in wells was detected between 16 and 28 days after cultures were initiated. Clones were transferred to 24-well tissue culture plates for regular maintenance. Three primary clones were selected for additional recloning. The probability that the parasites detected in one well are the progeny of a single infected erythrocyte approaches 0.99 for tertiary clones.

Evaluation of DNA "fingerprinting" for predicting the potential of E. coli O157:H7 isolates to cause hemolytic uremic syndrome (HUS).

Escherichia coli O157:H7 has been recognized since 1982 as a serious human pathogen spread by contaminated food and water. Pulsed-field gel electrophoresis has proven useful for identification of specific isolates/strains of this organism. Hemolytic uremic syndrome (HUS), generally occurring in children or the aged, is the most severe sequela associated with E. coli O157:H7 infection. The presently described work was designed to compare the genomic profile of isolates known to have caused HUS with those having had no such involvement. We asked the question: "Can we develop the means to recognize an 'HUS-prone' E. coli isolate and thereby alert medical personnel to the increased risk?" Twenty-two HUS-related and 10 HUS-unrelated E. coli O157:H7 samples were chosen for genomic analysis. Isolates were cultured overnight prior to being embedded in agarose gel plugs. Plugs were digested, using Xbal restriction endonuclease, and subjected to pulsed-field gel electrophoresis (PFGE) for 20 hours. Gels were stained with ethidium bromide, photographed under ultraviolet light, and Southern blotted. Radiolabeled toxin gene probes were used for hybridization assays. The two classes of isolates were compared by optical imaging software. A computer-generated dendrogram, based on restriction profiles, offered strong initial evidence that the HUS sequela may be produced by a particularly virulent and identifiable clone. The predictive value of this finding appears to be substantial.

Unique Salmonella choleraesuis surface protein affecting invasiveness. Possible inv related sequence.

TnphoA mutagenesis of a Salmonella choleraesuis isolate recovered from septicemic infection of feeder pigs resulted in 56 PhoA+ KnR StrR mutants. Thirty-five mutants exhibited reduced levels of invasion in the Hep-2 cell model and were examined by SDS-PAGE Western Blot analysis using an anti-alkaline phosphatase antibody to visualize the insertion gene products. A mutant which produced a gene fusion product of 95 kDa and exhibited > 90% reduction in invasion was subcloned. A 10 Kb BamHI fragment of the chromosome containing the phoA insert was detected by hybridization and cloned into a pGEM vector. The resulting 1657 base sequence contained a 1104 bp ORF with two short regions of homology with S. typhimurium invF and invG. one region of homology with lcrD of Yersinia pseudotuberculosis but contained largely unique sequences not contained in Gene Bank. The full length sequence was not obtained as there was no stop codon detected. The % G+C was 44%, considerably lower than that of the Salmonella chromosome, but compatible with the proposed Yersinia origin of the inv genes. The NH2 387 a.a. sequence includes 5 transmembrane regions, resembling the model derived from the hydrophobicity plot of S. typhimurium InvA.

Calcium-dependent protein phosphorylation in Babesia bovis and its role in growth regulation.

Intracellular growth of protozoan parasite Babesia bovis has been followed to study the effect of some chemical agents on growth regulation. Using an in vitro parasite culture system we present evidence that the normal growth of the parasite is dependent upon available calcium and a Ca2(+)-binding protein, calmodulin, because sequestration of either of these 2 components from the culture medium causes inhibition of parasitic growth. Further studies demonstrate that the parasite contains a protein kinase that can phosphorylate a 40-kDa parasitic protein and its activity is regulated by calcium and calmodulin. Both the enzyme and its substrate are present in the membrane of the parasite. In addition, the parasite also contains a highly active protein kinase C activity that is documented by phosphorylating histone, a known substrate for protein kinase C. These findings suggest a possible correlation between the growth of parasite and calcium/calmodulin-dependent protein phosphorylation activity.

Cutaneous hypersensitivity and isoantibody production in cattle injected with live or inactivated Anaplasma marginale in bovine and ovine erythrocytes.

Delayed cutaneous hypersensitivity and the production of isoagglutinins against normal bovine erythrocytes were measured in cattle inoculated with erythrocytic preparations containing live or inactivated Anaplasma marginale. The effect of blood group substances versus parasitic components on induction of delayed cutaneous hypersensitivity and isoimmunity was examined by using test antigens derived from normal and parasitized erythrocytes, virulent A marginale in bovine erythrocytes, and attenuated A marginale in ovine erythrocytes. The use of inactivated vaccine of bovine origin induced production of isoantibodies and cutaneous hypersensitivity to both bovine and ovine blood group factors, whereas a similar vaccine preparation of ovine origin stimulated antibodies and cutaneous reactivity only against ovine blood group factors.