Meticillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen in Pakistan and is emerging in the community. This is one of the first reports of the prevalent genotypes of MRSA in both hospital and community settings in Pakistan. Isolates collected in 2006-2007 were characterized by PFGE, staphylococcal cassette chromosome mec (SCCmec) typing and multilocus sequence typing (MLST). PFGE identified nine pulsotypes, the majority of isolates belonging to pulsotypes A (n570) and B (n538), which were predominant among hospital-onset MRSA (HO-MRSA) and community-onset MRSA (CO-MRSA) isolates, respectively. Among the HO-MRSA isolates, variants of SCCmec type III were prevalent, whilst SCCmec type IV or variants were predominant in the CO-MRSA isolates. MLST identified two principal sequence types, ST8 and ST239. An association was observed between ST8, PFGE pulsotype B and SCCmec type IV in the CO-MRSA (ST8-MRSA-IV). Similarly, ST239, PFGE pulsotype A and SCCmec type III were associated with HO-MRSA (ST239-MRSA-III). Therefore, the prevalent genotypes circulating in Pakistan at the time of study were ST8-MRSA-IV and ST239-MRSA-III in the community and hospital settings, respectively. A set of HO-MRSA isolates collected in 1997 were characterized by PFGE and SCCmec typing for comparison. The isolates belonged to two PFGE pulsotypes (A, n528; B, n511) and contained just two SCCmec types. These results suggest that an increase in genetic diversity occurred over the period 1997-2007 as a result of either microevolution or the importation of strains from surrounding areas.

No abstract

No abstract

BackgroundThe seroprevalence of human cytomegalovirus (HCMV) infection ranges from 30 to 90 % in developed countries. Reliable estimates of HCMV seroprevalence are not available for Pakistan. This study determined the seroprevalence and sociodemographic factors associated with HCMV infection in adult populations of Karachi, Pakistan.MethodsA seroprevalence survey was conducted on 1000 adults, including residents of two semi-urban communities, and visitors to a government and a private hospital. Questionnaire-based interviews were conducted. Sera were analysed for HCMV-specific IgG and IgM. Chi-square or Fisher’s exact test was used for comparing sociodemographic variables against seropositivity of HCMV-IgG or IgM. Multiple logistic regression modeling was performed for IgG seroprevalence and adjusted odds ratios were computed.ResultsThe seroprevalence of HCMV-IgG and IgM was 93.2 and 4.3 % respectively. 95.3 % of individuals who were IgM seropositive were also seropositive for IgG. Around 6 % (15/250) of women of childbearing age remained uninfected and were therefore susceptible to primary infection. HCMV-IgG seroprevalence was associated with being female (p = 0.001), increasing age (p = 0.002) and crowding index (p = 0.003) and also with lower levels of both education (p < 0.001) and income (p = 0.008). Seroprevalence also differed significantly by marital status (p = 0.008) and sampling location (p < 0.001). A logistic regression model for HCMV-IgG seroprevalence showed associations with being female (OR = 1.89; 95 % CI: 1.10–3.25), increasing age (OR = 3.95; 95 % CI: 1.79–8.71) and decreasing income (OR = 0.72; 95 % CI: 0.54–0.96). A strong association was observed between increased seroprevalence of HCMV-IgM and decreasing household size (p = 0.008).ConclusionsSeroprevalence of HCMV is very high in Pakistan, although 6 % of women of childbearing age remain at risk of primary infection. The IgM seropositivity observed in some individuals living in small household size (1–3 individuals) with persistent HCMV infection could have resulted from a recurrent HCMV infection. Future longitudinal research in pregnant women and neonates is required to study the trends in HCMV seroprevalence over time in Pakistan for the development of a potential HCMV prevention and vaccination programme.

Iron (Fe) and zinc (Zn) are recognised as micronutrients of clinical significance to public health globally. Major staple crops (wheat, rice and maize) contain insufficient levels of these micronutrients. Baseline concentrations in wheat and maize grains are 30 µg/g for Fe and 25 µg/g for Zn, and in rice grains, 2 µg/g for Fe and 16 µg/g for Zn. However, wheat grains should contain 59 μg Fe/g and 38 μg Zn/g if they are to meet 30–40% of the average requirement of an adult diet. Scientists are addressing malnutrition problems by trying to enhance Fe and Zn accumulation in grains through conventional and next-generation techniques. This article explores the applicability and efficiency of novel genome editing tools compared with conventional breeding for Fe and Zn biofortification and for improving the bioavailability of cereal grains. Some wheat varieties with large increases in Zn concentration have been developed through conventional breeding (e.g. BHU1, BHU-6 and Zincol-2016, with 35–42 µg Zn/g); however, there has been little such success with Fe concentration. Similarly, no rice variety has been developed through conventional breeding with the required grain Fe concentration of 14.5 µg/g. Transgenic approaches have played a significant role for Fe and Zn improvement in cereal crops but have the limitations of low acceptance and strict regulatory processes. Precise editing by CRISPR-Cas9 will help to enhance the Fe and Zn content in cereals without any linkage drag and biosafety issues. We conclude that there is an urgent need to biofortify cereal crops with Fe and Zn by using efficient next-generation approaches such as CRISPR/Cas9 so that the malnutrition problem, especially in developing countries, can be addressed.