Difference In Carrier Rates Research Articles

Inherited DNA Repair Gene Mutations in Men with Lethal Prostate Cancer.

Germline variants in DNA repair genes are associated with aggressive prostate cancer (PrCa). The aim of this study was to characterize germline variants in DNA repair genes associated with lethal PrCa in Finnish and Swedish populations. Whole-exome sequencing was performed for 122 lethal and 60 unselected PrCa cases. Among the lethal cases, a total of 16 potentially damaging protein-truncating variants in DNA repair genes were identified in 15 men (12.3%). Mutations were found in six genes with CHEK2 (4.1%) and ATM (3.3%) being most frequently mutated. Overall, the carrier rate of truncating variants in DNA repair genes among men with lethal PrCa significantly exceeded the carrier rate of 0% in 60 unselected PrCa cases (p = 0.030), and the prevalence of 1.6% (p < 0.001) and 5.4% (p = 0.040) in Swedish and Finnish population controls from the Exome Aggregation Consortium. No significant difference in carrier rate of potentially damaging nonsynonymous single nucleotide variants between lethal and unselected PrCa cases was observed (p = 0.123). We confirm that DNA repair genes are strongly associated with lethal PrCa in Sweden and Finland and highlight the importance of population-specific assessment of variants contributing to PrCa aggressiveness.

Comparing ethnicity-based and expanded carrier screening methods at a single fertility center reveals significant differences in carrier rates and carrier couple rates

To evaluate the efficiency of expanded carrier screening (ECS) compared with ethnicity-based screening in identifying carriers. A total of 4232 infertility patients underwent ECS from a single genetic testing laboratory at our center between June 2013 and July 2015. Self-reported ethnicity was recorded. Carrier rates based on ECS were calculated. In addition, carrier status was determined for two other screening panels: ethnicity-based guidelines or the ECS panel recommended by the American College of Obstetricians and Gynecologists (ACOG) using ECS results. Carrier rate and carrier couple rates were compared in the overall study population and in each self-reported ethnicity. The ECS panel used to screen the patient population identified 1243 carriers (29.4%). For the same population, ethnicity-based screening and the ACOG panel would have identified 359 (8.5%) and 659 carriers (15.6%), respectively, representing statistically significant differences. Differences in identifying carriers across self-reported ethnicities varied. In 15 couples (1.2%), both partners carried pathogenic variants for the same genes, 47% of whom would have been missed had screening been ethnicity-based. We propose that all reproductive-aged women should be offered ECS. Carrier couple rates would likely increase further with expansion of the panel, playing a pivotal role in preventing genetic disease in fertility clinics.

Molecular typing of Streptococcus suis isolates from Iberian pigs: A comparison with isolates from common intensively-reared commercial pig breeds

The Iberian pig (IP) is a traditional Spanish breed variety of the domestic pig (Sus scrofa domesticus) with high economic importance because of the value of the dry-cured products in national and international markets. The genetic characteristics of tonsillar and clinical Streptococcus suis isolates from the IP maintained under extensive or intensive management conditions were investigated. S. suis isolates from IP pigs were compared with S. suis isolates from intensively-farmed pigs of common breeds (CBP). S. suis was isolated from 48.4% of the IP tonsils examined, indicating wide distribution among IP pigs.Serotypes 1 (9.4%), 2 (8.6%) and 9 (7%) were the most commonly found, although a high percentage of S. suis isolates were not typeable by coagglutination testing. No significant differences in carrier rates or serotype diversity were observed between management systems, indicating that intensive farming does not influence S. suis colonisation. Both pulsed-field gel electrophoresis and multiple-locus variable number tandem repeat analysis showed a serotype-based distribution of S. suis IP isolates. Serotypes 1 and 2 S. suis isolates were grouped in the same cluster, whereas isolates of serotypes 9 and 7 were assigned to another cluster. All clinical and most tonsillar serotype 2 IP isolates were assigned to sequence type 1 (ST1) and exhibited the virulence genotype mrp+/epf+/sly+, indicating a high distribution of this genetic lineage among IP as well as a population of serotype 2 common to IPs and CBPs. The only clinical isolate of serotype 9 from IP was assigned to ST123, a sequence type associated with clinical isolates in CBPs in Spain.

Methicillin Resistant Staphylococcus aureus Carriage, Antibiotic Resistance and Molecular Pathogenicity among Healthy Individuals Exposed and Not Exposed to Hospital Environment.

Healthcare workers as well as healthy community-dwelling individuals may be colonised by methicillin-resistant Staphylococcus aureus (MRSA). Healthcare workers who carry MRSA may transmit it to patients, causing various nosocomial infections. Literature shows that the differences between MRSA isolated from healthcare settings and from community settings, with regard to multi-drug resistance (traditionally exhibited by the former) and possession of pvl genes (traditionally exhibited by the latter), is diminishing due to a large community reservoir and increasing influx of community harboured strains into the hospital. However, there is no literature on the current scenario in India. This study examines the influence of exposure to hospital environment on MRSA carriage, antimicrobial resistance patterns of MRSA, and the presence of genes encoding five extracellular pathogenicity determinants (pvl, sea, seb, tsst-1 and hly a). Nasal, throat and palmar swabs were collected from 119 nursing students of the age group 18-23 years (exposed group) and 100 age matched pharmacy students (non-exposed group). S. aureus was identified and antibiogram obtained as per Clinical and Laboratory Standards Institute (CLSI) guidelines. MRSA was detected by cefoxitin disc diffusion test and by growth on oxacillin screen agar as per CLSI guidelines. Conventional PCR was performed for mecA, pvl, sea, seb, tsst-1 and hly a. The differences in carrier rates, antibiotic resistance patterns and expression of extracellular pathogenicity determinants between MRSA isolates from the two study groups were not significant, and pvl was found in all the MRSA isolates. The nursing students carried MRSA strains similar to those carried by the non-exposed group. Our results suggest that healthcare workers could act as a link and transmit MRSA acquired from the community to patients.

Carrier Rates of Four Single-Gene Disorders in Croatian Bayash Roma

To assess how specific population history, different migration routes, isolation, and endogamy practices contributed to the distribution of several rare diseases found in specific Roma groups, we conducted a population-based research study of rare disease mutations in Croatian Vlax Roma. We tested a total of 427 subjects from Baranja and Međimurje for the presence of four mutations causing hereditary motor and sensory neuropathy type Lom (HMSNL), GM1 gangliosidosis (GM1), congenital cataracts, facial dysmorphism and neuropathy (CCFDN), and limb girdle muscle dystrophy type 2C (LGMD2C), using the RFLP-PCR method to estimate carrier frequencies. We identified a total of four individuals heterozygous for the mutation causing HMSNL in the Baranja population, with a carrier rate amounting to 1.5%. Carriers for other three mutations causing GM1, CCFDN, and LGMD2C were not found in our sample. The carrier rate for the HMSNL mutation in Baranja is lower than in other Vlax Roma groups. In addition, distinct differences in carrier rates between the Croatian Vlax groups point to different genetic history, despite their belonging to the same Roma migration category and subgroup. The difference in carrier rates is either the result of admixture or the reflection of a greater extent of genetic drift since recent founding, maintained by a high degree of endogamy.

The bacteriological ecosystem of the skin of children in an African tropical environment (Tanzania)

Using a standardized method for sampling, the aerobic microbial flora of the skin of ninety-five children in Dar es Salaam, Tanzania, was studied qualitatively and quantitatively. The subjects comprised three groups; group A, thirty-seven normal infants (below the age of 1 year); group B, twenty-nine infants with various bacterial skin lesions; and group C, twenty-nine nursery school children between 4-5 and 7 years. The following observations were made: (I) The quantitative results indicated; (a) great variation between individuals, which was more marked among the females; (b) lower bacterial counts in infants than in older children; (c) counts were not affected by the presence of infection or state of cleanliness; (d) there were some differences between females and males and between different ethnic groups. (2) Qualitatively, the types of organisms isolated were similar to those reported elsewhere. There were differences in carrier rates of many organisms but these were most striking with Staphylococcus aureus and Staph. albus. It is concluded that there are great differences in carrier rates between persons in a tropical African environment and those studied elsewhere. These difference may be due to environmental, geographical or ethnic factors. Such observations call for more studies in this area to establish the normal flora.

Frequency and distribution in East Asia of 12 mutations identified in the SLC25A13 gene of Japanese patients with citrin deficiency

Deficiency of citrin, a liver-type mitochondrial aspartate-glutamate carrier (AGC), encoded by the SLC25A13 gene on chromosome 7q21.3, causes autosomal recessive disorders: adult-onset type II citrullinemia (CTLN2) and neonatal hepatitis associated with intrahepatic cholestasis (NICCD). So far, we have described 12 SLC25A13 mutations: 11 were from Japan and one from Israel. Three mutations found in Chinese and Vietnamese patients were the same as those in Japanese patients. In the present study, we identified a novel mutation IVS6+1G>C in a Japanese CTLN2 patient and widely screened 12 SLC25A13 mutations found in Japanese patients in control individuals from East Asia to confirm our preliminary results that the carrier frequency was high in Asian populations. Mutations 851-854del and 1638-1660dup were found in all Asian countries tested, and 851-854del associated with 290-haplotype in microsatellite marker D7S1812 was especially frequent. Other mutations frequently detected were IVS11+1G>A in Japanese and Korean, S225X in Japanese, and IVS6+5G>A in Chinese populations. We found a remarkable difference in carrier rates in China (including Taiwan) between north (1/940) and south (1/48) of the Yangtze River. We detected many carriers in Chinese (64/4169 = 1/65), Japanese (20/1372 = 1/69) and Korean (22/2455 = 1/112) populations, suggesting that over 80,000 East Asians are homozygotes with two mutated SLC25A13 alleles.

Carriage ofStaphylococcus aureusamong 104 healthy persons during a 19-month period

The present study was undertaken to investigate the frequency of the nasal carrier rate of Staphylococcus aureus. The investigation was performed on 104 healthy persons. The total number of swabs performed was 1498 and this resulted in isolation of 522 S. aureus strains. All strains have been identified, tested for antibiotic susceptibility, and phage-typed. The carrier-index (number of positive swabs/number of total swabs for each individual person) was compared with different sampling and culturing methods, phage type, age, and resistance to antibiotics. There was statistical difference in carrier rate according to sex (P < 0.05). Among the 104 persons 15 (14.4%) were persistent carriers, 17 (16.3%) intermittent carriers, 55 (52.9%) occasional carriers and 17 (16.3%) non-carriers. Among intermittent and occasional carriers the phage-type distribution was different from the S. aureus strains isolated from Danish hospitalized patients in 1992, while the persistent carriers had similar phage-type distribution.

Hepatitis B Infection Among Chinese STD Patients in Kuala Lumpur, Malaysia

This study documents the prevalence of Hepatitis B serological markers among STD patients who have had multiple sexual partners in Kuala Lumpur, Malaysia, and compares the rates with those of a sample of the population with single or no sexual partners. A total of 336 Chinese STD patients (multiple partners group) and 234 Chinese control subjects (non-multiple partner group) were screened. Those with a history of blood transfusion or parenteral drug abuse had been excluded from the study, and all study subjects were heterosexuals. The overall carrier rate was 9.2% for the multiple partner group (MP group) and 6.8% for the non-multiple partner group (NMP group). Infection rates were 64.3% for the MP-group and 38.9% for the NMP group. After adjustments for age and sex, there was no significant difference in carrier rates between the two groups, but infection rates were significantly different with the MP group, being 3.2 times more likely to acquire infection than the NMP group. The study concludes that in heterosexuals, those with multiple sexual partners have increased chances of acquiring HBV infection.

Hepatitis B in seven hospitals for the mentally handicapped

Patients in seven hospitals for the mentally handicapped were screened for markers of hepatitis B infection. Of 2239 patients, 123 (5.5 per cent) were carriers of hepatitis B surface antigen (HBsAg) and a third of these were 'infectious' (negative for antibody to hepatitis B e antigen). Patients with Down's syndrome (DS) were 18 times more likely to be 'infectious' carriers than those without, and male patients were six times more likely to be 'infectious' carriers than female patients. There was a wide difference in carrier rate among the various hospitals. In the hospital with the highest carrier rate (12.5 per cent), 60 per cent of male patients with DS were carriers of HBsAg and of these two-thirds were 'infectious'. The carrier rate decreased with age, but the proportion of carriers who were hepatitis B e antigen positive was unaffected by age.

1979-fiscal-year-survey for throat-carriers of hemolytic streptococci among children in Tokyo (author's transl)

The surveys for throat-carriers of hemolytic streptococci among children of elementary schools and kindergartens in Tokyo were undertaken in November, 1979 and in February, 1980.1) Included in the surveys were 552 children of 7 elementary schools and 2 kindergartens in 7 wards and 1 city of Tokyo. In autumn and winter surveys, 546 and 527 children were examined (521 being inspected at both times), and 256 strains of hemolytic streptococci were isolated from 135 (24.7%) and 121 (23.0%) children, respectively.2) The streptococci wereserogrouped to be 233 group A (91.0%) 15 group G, 6 group B, and 2 group C strains. Serotypes of the group A strains were, in the order of frequencies, T-types 1 (19.7%), 13 (17.7%), 6 (13.3%), 12 (11.6%) and so on. The rates of types 1 and 13 strains were significantly higher in Adachi-ku ward.3) Among 521 children examined, 53 gave positive cultures at both surveys. Serogroups or serotypes of in the autumn and winter surveys isolates were identical in 27 cases (50.9%).4) Considerable differences in carrier rates (6.1-38.4%) were seen among institutions.5) The carrier rates in the autumn and in the winter surveys of 1979 fiscal yearwere not so much different from the corresponding rates obtained in 1977 and 1978 fiscal years.

Studies on hepatitis B surface antigen and antibody in Nauru. I. Distribution amongst Nauruans.

The age specific prevalence of hepatitis B surface antigen and antibody was studied among a random sample of Nauruans over the age of 10 years. Overall, 79% of subjects showed evidence of past infection with hepatitis B virus with the highest prevalence among young people. While there was no difference in the infection rate between males and females, the carrier rate in males was 50% higher. In both sexes the carrier rate declined with increasing age. Significant differences in carrier rates were detected among people living in different parts of the island.

Frequency of Australia antigen in blood donors in Singapore.

There is increasing agreement that Australia antigen (Au)-positive subjects should not be accepted as blood donors. This practice is being adopted in Western countries where the frequency of Au is approximately 0.1%. The frequency of Au is much higher 1 in tropical countries. The serum samples of 98.4% (2,563) of all donors in January 1971 were screened by electro-osmodiffusion (EOD) 2 in order to investigate the frequency of Au in blood donors in Singapore (Table 1). The Au carrier rate was relatively high. An ethnic difference in carrier rate in that Chinese had a higher frequency than Malays, Indians, and others was observed. All except nine serum samples were reexamined for Au by immune adherence haemagglutination (IAHA) (Table 2). The IAHA is approximately 1,000 times more sensitive than EOD. 3 Twice the number of Au carriers were detected by the more sensitive technique. The ethnic difference suggested by the EOD

Posttransfusion hepatitis after open-heart operations. Incidence after the administration of blood from commercial and volunteer donor populations.

The incidence of icteric and anicteric hepatitis was determined prospectively in 110 patients undergoing open-heart operations in which cardiopulmonary bypass was used. Patients were supplied with blood from two commercial blood banks (82 patients), or from local volunteer donors (28 patients). Serial determinations of serum transaminase levels were obtained for six months following operation. Hepatitis developed in 51% (42) of the recipients of commercial blood, but the disease did not occur in any patient who received blood from volunteer donors. The hepatitis carrier rate for commercial blood donors was 6.3%, but, for volunteer donors, was less than 0.6%. This difference in carrier rates probably reflects differences in the donor populations.

Posttransfusion Hepatitis After Open-Heart Operations

The incidence of icteric and anicteric hepatitis was determined prospectively in 110 patients undergoing open-heart operations in which cardiopulmonary bypass was used. Patients were supplied with blood from two commercial blood banks (82 patients), or from local volunteer donors (28 patients). Serial determinations of serum transaminase levels were obtained for six months following operation. Hepatitis developed in 51% (42) of the recipients of commercial blood, but the disease did not occur in any patient who received blood from volunteer donors. The hepatitis carrier rate for commercial blood donors was 6.3%, but, for volunteer donors, was less than 0.6%. This difference in carrier rates probably reflects differences in the donor populations.

Asymptomatic throat carriage rate and antimicrobial resistance pattern of &lt;i&gt;Streptococcus pyogenes&lt;/i&gt; in Nepalese school children

Streptococcus pyogenes or Group A streptococcus (GAS) causes several suppurative and non suppurative infections. In addition to pharyngitis and skin infections, GAS are also the causative agent of post-streptococcal infection syndromes such as acute rheumatic fever (ARF) and post-streptococcal glumerulonephritis (PSG). GAS frequently colonises in the throat of an asymptomatic person. Pharyngeal carriage rates of GAS among healthy school children vary with geographical location and seasons. We carried out this preliminary study to determine the throat carriage rate and antimicrobial resistance trend of Streptococcus pyogenes or Group A streptococcus (GAS) among the Nepalese school children. Four schools situated at different locations of Kathmandu valley were included in the study. Throat swabs from 350 students of age group 5-15 years were collected, immediately transported to the laboratory and were processed for S. pyogenes following standard microbiological procedures. Antimicrobial susceptibility testing of the isolates was performed by Kirby Bauer disc diffusion method following CLSI guidelines. S. pyogenes was isolated from 10.9% (38/350) of the screened children. The GAS colonisation rate was statistically insignificant (P>0.05) with sex and age sub-groups, although the rate was slightly higher among girls and age sub-group 9-12 years. No significant difference in carrier rate was observed among different schools (P>0.05). All isolates were susceptible to azithromycin. No resistance was detected for penicillin and its derivative antibiotic ampicillin. Highest resistance rate was observed for cotrimoxazole (71.0%) followed by chloramphenicol (7.8%), ciprofloxacin (5.2%) and erythromycin (5.2%). Antibiotic resistant GAS isolated from asymptomatic Nepalese school children is a public health concern. When screened and appropriately treated with antibiotics, carriers can be prevented from spreading of streptococcal infections in the school environment and the community. Preventing cross infections would ultimately reduce the incidence of life-threatening sequelae which are debilitating and difficult to treat. It is recommended to conduct regular screening and GAS surveillance in schools, and maintain rational use of antibiotics to minimise GAS carriage/infections and resistance.