Abstract Emergence of plasmid mediated colistin and extended spectrum β-lactamases (ESBL) resistant genes has been impacted the efficacy of colistin and β-lactams drugs like 3rd, 4th generation cephalosporin. Current study was aimed to investigate antimicrobial resistance genes (ARGs) among Escherichia coli isolates from meat producing commercial broilers in Pakistan. Two hundred (n=200) fecal samples were collected during January-2018 to August-2019. For isolation of E. coli, pink colonies on MacConkey agar were transferred to EMB agar. Metallic sheen color colonies were tested biochemically using API-20E kit. The molecular identification of E. coli (n=153) was targeted by amplification of uid gene through polymerase chain reaction (PCR) and different ARGs i.e. gentamicin, streptomycin, tetracycline, colistin, β-lactams drugs, quinolone and ampicillin followed by sequence analysis. Genotypically, followed by phenotypically of resistant ARGs of isolated PCR-confirmed E. coli (153) shoed resistant against gentamicin (aac(3)-IV), streptomycin (aadA1), tetracycline (tetA), colistine (mcr-1), ampicillin (bla-TEM) and bla-CTX-M were 86%, 88%, 86%, 88%, 83% & 77% respectively. 33/38 (86%) of the isolate was positive for quinolone resistance. Colistine (mcr-1), ESBLs (bla-TEM) and (bla-CTX-M) resistance genes were 88%, 83% and 77% respectively. About 33 isolated E. coli harbored the both mcr-1 and ESBLs genes. All of E. coli isolates were found sensitive to ceftriaxone (CTX-30) and imipenem (IMP-10). The Isolated E. coli showed single or multi clade decadency. The E. coli and ARGs sequences showed single or multi clade decadency. This is first comprehensive study from Pakistan that described the molecular evidences of ARGs and their co-existence in single isolates originated from commercial poultry. Commercial chicken (Broilers) can act as melting pot of antibiotic resistance genes for human being. It is alarming situation for surveillance of antibiotic resistance program because of more regulated prescription of antimicrobial agents in Pakistan

Resumo O surgimento de colistina mediada por plasmídeo e genes de resistência a β-lactamases de espectro estendido (ESBL) afetou a eficácia de medicamentos colistina e β-lactâmicos, como as cefalosporinas de 3ª e 4ª geração. O presente estudo teve como objetivo investigar genes de resistência antimicrobiana (ARGs) entre isolados de Escherichia coli em frangos de corte comerciais no Paquistão. Duzentas (n = 200) amostras fecais foram coletadas durante janeiro de 2018 a agosto de 2019. Para o isolamento de E. coli, colônias rosas em ágar MacConkey foram transferidas para ágar EMB. As colônias de cores de brilho metálico foram testadas bioquimicamente usando o kit API-20E. A identificação molecular de E. coli (n = 153) foi direcionada pela amplificação do gene uid através da reação em cadeia da polimerase (PCR) e diferentes ARGs, ou seja, gentamicina, estreptomicina, tetraciclina, colistina, medicamentos β-lactâmicos, quinolona e ampicilina, seguido de análise de sequência. Genotipicamente, seguido por fenotipicamente de ARGs resistentes de E. coli isoladas foram confirmadas por PCR (153) como resistente contra gentamicina (aac(3)-IV), estreptomicina (aadA1), tetraciclina (tetA), colistina (mcr-1), ampicilina (bla-TEM) e bla-CTX-M, demonstrando resultados de 86%, 88%, 86%, 88%, 83% e 77%, respectivamente. Cerca de 33/38 (86%) do isolado foi positivo para resistência às quinolonas. Os genes de resistência à colistina (mcr-1), ESBLs (bla-TEM) e (bla-CTX-M) foram 88%, 83% e 77%, respectivamente. Cerca de 33 E. coli isoladas continham os genes mcr-1 e ESBLs. Todos os isolados de E. coli foram considerados sensíveis à ceftriaxona (CTX-30) e imipenem (IMP-10). A E. coli isolada apresentou decadência de um ou vários clados. As sequências de E. coli e ARGs apresentaram decadência de um ou vários clados. Este é o primeiro estudo abrangente do Paquistão que descreveu as evidências moleculares de ARGs e sua coexistência em isolados únicos originados de aves comerciais. Dessa forma, é possível concluir que o Frango comercial (Broilers) pode atuar como caldeirão de genes de resistência a antibióticos para o ser humano. É uma situação alarmante para a vigilância do programa de resistência a antibióticos devido à prescrição mais regulamentada de agentes antimicrobianos no Paquistão

Higher olefins are produced as a by product in a number of refinery processes and are one of the potential raw materials to produce propylene. In the present study, FCC model feed compound was considered to explore the olefin cracking features and options to enhance propylene using 30% SAPO-34 zeolite as catalyst in a micro-reactor. The superior selectivity of propylene (73 wt%) and higher total olefin selectivity was obtained over 30% SAPO-34 catalyst than over Y or ZSM-5 zeolite catalysts. The thermodynamical constraints were found to be relatively less serious in the case of 1-hexene conversion. Most of the 1-hexene follows a direct cracking pathway to give two propylene molecules, due to weak acid sites and better diffusion opportunities. The higher temperature and short residence time could also suppress the hydrogen transfer reactions. From OPE (olefins performance envelop) the products were classified as primary, secondary, or both. Iso-hexene (2-methyl-2-pentene) cracking was also analyzed in order to justify a shape selective effect of the SAPO-34 catalyst. A detailed integrated reaction network together with an associated mechanism was proposed and discussed in detail for their fundamental importance in understanding the olefin cracking processes over SAPO-34.