BackgroundGlobally, regions at the highest risk for emerging infectious diseases are often the ones with the fewest resources. As a result, implementing sustainable infectious disease surveillance systems in these regions is challenging. The cost of these programs and difficulties associated with collecting, storing and transporting relevant samples have hindered them in the regions where they are most needed. Therefore, we tested the sensitivity and feasibility of a novel surveillance technique called xenosurveillance. This approach utilizes the host feeding preferences and behaviors of Anopheles gambiae, which are highly anthropophilic and rest indoors after feeding, to sample viruses in human beings. We hypothesized that mosquito bloodmeals could be used to detect vertebrate viral pathogens within realistic field collection timeframes and clinically relevant concentrations.Methodology/Principal FindingsTo validate this approach, we examined variables influencing virus detection such as the duration between mosquito blood feeding and mosquito processing, the pathogen nucleic acid stability in the mosquito gut and the pathogen load present in the host’s blood at the time of bloodmeal ingestion using our laboratory model. Our findings revealed that viral nucleic acids, at clinically relevant concentrations, could be detected from engorged mosquitoes for up to 24 hours post feeding by qRT-PCR. Subsequently, we tested this approach in the field by examining blood from engorged mosquitoes from two field sites in Liberia. Using next-generation sequencing and PCR we were able to detect the genetic signatures of multiple viral pathogens including Epstein-Barr virus and canine distemper virus.Conclusions/SignificanceTogether, these data demonstrate the feasibility of xenosurveillance and in doing so validated a simple and non-invasive surveillance tool that could be used to complement current biosurveillance efforts.

A total of 32 Vibrio cholerae isolates were collected during a recent large cholera outbreak in Eastern India. Biochemical and serological studies revealed that all of the isolates belonged to serogroup O1, biotype El Tor, serotype Ogawa. Two multiplex PCR assays confirmed the presence of various toxigenic and pathogenic genes -ace, ctxAB, hlyA, ompU, ompW, rfbO1, rtx, tcp, toxR and zot -in all of the isolates. Sequencing of the ctxB gene from the isolates revealed a novel mutation in the gene. Sequencing also confirmed the presence of altered cholera toxin B of the classical biotype in all of the El Tor isolates, suggesting infection of isolates by classical CTXW. The molecular diversity of V. cholerae isolates studied by enterobacterial repetitive intergenic consensus sequence PCR, BOX-PCR and randomly amplified polymorphic DNA analysis uniformly showed the clonal relationship among the outbreak V. cholerae O1 isolates. The results of this study suggest that cholera-causing V. cholerae strains are constantly evolving in epidemic areas, highlighting the potential of the emergence of more virulent strains.

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Multidrug-resistant Gram-negative bacteria are associated with higher mortality and morbidity among solid organ transplant recipients. Carbapenems, the broad spectrum β lactam agents are frequently used as a drug of last resort for the treatment of the infections caused by MDR Gram negative bacteria. They are the cause of production of β lactamases (Klebsiella pneumoniae Carbapenemase-KPC and Metallo β lactamases-MBL) among Gram negatives. The objective of this study was to explore the present scenario of β-lactamases mainly KPC along with MBL productions in Gram negative clinical samples. This hospital based cross sectional study was conducted from January 2016 to June 2016 at Human Organ Transplant Center, Kathmandu, Nepal.The standard microbiological methods were used for the isolation and identification of all the isolates and screening the meropenem resistant isolates by Kirby Bauer Disc Diffusion method. The confirmatory detection of KPC and MBL was done by the β-lactamase inhibition disc method. The inhibiting compound Phenyl Boronic Acid (PBA) and Ethylenediamine tetra-acetic Acid (EDTA) were used. Out of 1500 different clinical samples processed, only 10% (15/1500) Gram-negative organisms were isolated and identified. MDR was detected in 77.3% isolates. Majority of the Meropenem resistant (50%) isolates being E. coli (69.3%) followed by K. pneumoniae (18.6%). Carbapenemase MBL was prevalent among 29% of the isolates while KPC was reported among 12.6% isolates.The study demonstrated the increase in trend of carbapenemase production is creating turmoil in treatment options in health centers. This study put forward a prospective need for the development of such drugs or other mechanisms which could better work to overcome the resistance due to carbapenemase production.

ObjectivesThis study was carried out to determine the prevalence of metallo-β-lactamases (MBLs) producing Pseudomonas aeruginosa in imipenem-nonsusceptible isolates and to detect MBL-encoding genes among MBLs-positive isolates.ResultsMetallo-β-lactamases production was detected in 68.6% isolates of P. aeruginosa with reduced susceptibility to imipenem. The bla VIM-2 gene was detected in 75% isolates and bla IMP-1 was detected in 25% isolates. All MBLs-positive isolates were multidrug resistant with a high level of resistance to imipenem (MIC 16 to ≥ 32 µg/ml), meropenem (MIC 16 to ≥ 32 µg/ml), and ceftazidime (MIC 64 to ≥ 512 µg/ml). All MBL-positive isolates were susceptible (MIC ≤ 2 µg/ml) to colistin. We found high prevalence of MBL-producing P. aeruginosa. To our knowledge this is the first report of detection of bla VIM-2 and bla IMP-1 in P. aeruginosa from Nepal. This indicates the need for awareness to prevent the spreading of these resistant isolates in hospital setting.