PATHOGENICITY OF BACTERIA ENTEROBACTERIACEAE ON ZEBRAFISH AS ANIMAL MODEL

Enterobacteriaceae are Gram negative bacteria contain endotoxin and exotoxins which are requirements for pathogenic bacteria and act as opportunistic pathogens. The purpose of this research was to determine the ability of Enterobacteriaceae bacteria to infect zebrafish (Danio rerio) by observing anatomical pathology, mortality, time death and cumulative time of death. The method used in this research is a completely randomized design method (CRD). This research was conducted in three stages, first preparation of zebrasfish as animal model by average size 3-5cm and reach three months old. Second, bacterial cultures from 10 species of Enterobacteriaceae were Escherichia coli 1, E. coli 2, Enterobacter cloacae 1, Acinetobacter calcoaceticus, Enterobacter amnigenus 1, Enterobacter amnigenus 1, Escherichia coli 3, Pantoea spp., E. cloacae 1, E. cloacae 2, E. cloacae 3, cultured in Brain Heart Infused Broth (BHIB) and later media washed with Phospate Buffer Saline (PBS) 0.45%. The third stage was bacterial infection to zebrafish using immersion method with each treatment repeated 3 times and observed for 120 hours. The results showed 10 species that used caused death (mortality), the highest mortality in fish that infected with E. coli 2 and E. cloacae 1 with a percentage of 66.67% infected by E. coli 2 and E. cloacae 1. Anatomical pathology in the external organs and internal organs showed post-infectious symptoms. Infection occurred with mean time to death of 12-86 hours, as long as the cumulative time of fish death caused by E. coli 2, A.cinetobacter calcoaceticus and E. cloacae 1 causing death from 24 hours after infection until the end of observation.

Assessment and incidence of fish associated bacterial pathogens at hatcheries of Azad Kashmir, Pakistan

Fish is the most indispensable source of proteins for individuals and have high nutritional value. On the other hand, the fish culturing raised issues of fish health due to close contact between the aquatic environment and the fish pathogens. So, the aim of the current study was to identify the bacterial pathogens and screen the injured Rainbow trout rearing in different trout hatcheries run under fisheries department of the government of Azad Jammu and Kashmir, Pakistan. Seven bacterial pathogens such as Shigella flexneri, Enterobacter amnigenus, Salmonella Typhimurium, Serratia odorifera, Pseudomonas aeruginosa, Streptococcus pyogenes, and Bacillus cereus were isolated and identified. Results revealed that the injury of fish specimens was due to overcrowding. Instead of rainbow coloration, specimens have darker black in color. The water of ponds was not clean and clear and such conditions was because of the greater quantity of feed thrown in the water. It was concluded that poor hygienic water condition and overloading allowed the opportunistic bacterial contaminations to succeed which cause a serious threat to hatcheries.

Simultaneous and sequential influence of metabolite complexes of Lactobacillus rhamnosus and Saccharomyces boulardii and antibiotics against poly-resistant Gram-negative bacteria

For the first time the poly-resistant strains of Gram-negative microorganisms were studied for the sensitivity to combined simultaneous and sequential influence of metabolic complexes of Lactobacillus rhamnosus GG and Saccharomyces boulardii, obtained by the author’s method without using the growth media, with antibiotics. The synergic activity of antibacterial preparations and metabolic complexes of L. rhamnosus GG and S. boulardii were studied using modified disk-diffusive method of Kirby-Bauer. During the sequential method of testing (at first the microorganisms were incubated with structural components and metabolites, then their sensitivity to the antibacterial preparations was determined), we observed increase in the diameters of the zones of growth inhibition of Pseudomonas aeruginosa PR to the typical antibiotics (gentamicin, amіcyl, ciprofloxacin, сefotaxime) and non-typical (lincomycin, levomycetin) depending on the tested combinations. Acinetobacter baumannii PR exhibited lower susceptibility: growth inhibition was seen for the combination with ciprofloxacin, сefotaxime, levomycetin. Susceptibility of Lelliottia amnigena (Enterobacter amnigenus) PR increased to levofloxacin, lincomycin. The zones of growth inhibition of Klebsiella pneumoniae PR increased to gentamicin, amіcyl, tetracycline, сeftriaxone. Maximum efficiency was determined during sequential combination of antibiotics with separate metabolic complexes of L. rhamnosus and S. boulardii, and also their combination (to 15.2, 20.2 and 15.4 mm respectively) compared with their simultaneous use (to 12.2, 15.2 and 13.0 mm respectively) for all the tested poly-resistant pathogens, regardless of the mechanism of action of antibacterial preparation. Metabolic complexes of L. rhamnosus GG and S. boulardii, due to increase in the susceptibility of microorganisms, can decrease the therapeutic concentration of antibiotic, slow the probability of the development of resistance of microorganisms, and are therefore promising candidates for developing “accompanying medications” to antibiotics and antimicrobial preparations of new generation.

Chromium Resistant Bacteria: Impact on Plant Growth in Soil Microcosm

Three chromium resistant bacterial strains, Pseudomonas fluorescens PF28, Enterobacter amnigenus EA31 and Enterococcus gallinarum S34 isolated from tannery waste contaminated soil were used in this study. All strains could resist a high concentration of K2Cr2O7 that is up to 300 mg/L. The effect of these strains on clover plants (Trifolium campestre) in the presence of two chromium salts CrCl3 and K2Cr2O7 was studied in soil microcosm. Application of chromium salts adversely affected seed germination, root and shoot length. Bacterial inoculation improved the growth parameters under chromate stress when compared with non inoculated respective controls. There was observed more than 50% reduction of Cr(VI) in inoculated soil microcosms, as compared to the uninoculated soil under the same conditions. The results obtained in this study are significant for the bioremediation of chromate pollution.

Respuesta vegetal de acacia decurrens a la inoculación con rizobacterias promotoras de crecimiento vegetal bajo estrés salino

La salinización del suelo se considera como uno de los factores ambientales limitantes del crecimiento y productividad de los cultivos en el mundo, principalmente en regiones áridas y semiáridas. Una alternativa para aliviar el estrés causado por este factor abiótico es el uso de Rizobacterias Promotoras de Crecimiento Vegetal (RPCV), las cuales pueden contribuir en el crecimiento de las plantas a través de sus múltiples funciones. El objetivo de la investigación fue realizar el aislamiento, caracterización y determinación del efecto de bacterias de vida libre halotolerantes asociadas a Acacia decurrens. Los microorganismos se caracterizaron bioquímicamente a partir de la producción de amonio, determinación de la actividad de celulosa, producción de exopolisacáridos, producción de Índoles totales, determinación cuantitativa de solubilización de fósforo y genéticamente con el 16S rRNA. Bajo condiciones de invernadero se evaluó el efecto de los microorganismos seleccionados sobre la promoción de crecimiento de Acacia decurrens a partir de variables morfométricas. Los resultados demostraron que los nueve aislamientos en estudio presentaron en general una buena actividad metabólica excepto los aislamientos ACSA12 y ACSA19 que no expresaron producción celulolítica. La respuesta de la planta evidenció que los aislamientos T4, T5 y T7 incrementaron de manera significativa la biomasa y desarrollo de la misma (p0.05). Los aislamientos fueron identificados genéticamente como Pantoea deleyi ACSA12, Enterobacter amnigenus ACSA14 y Serratia liquefaciens ACSA19.

Characteristics of Extended-Spectrum β-Lactamase- and Carbapenemase-Producing Enterobacteriaceae Isolates from Rivers and Lakes in Switzerland

ABSTRACTOne of the currently most relevant resistance mechanisms inEnterobacteriaceaeis the production of enzymes that lead to modern expanded-spectrum cephalosporin and even carbapenem resistance, mainly extended-spectrum β-lactamases (ESBLs) and carbapenemases. A worrisome aspect is the spread of ESBL and carbapenemase producers into the environment. The aim of the present study was to assess the occurrence of ESBL- and carbapenemase-producingEnterobacteriaceaeand to further characterize ESBL- and carbapenemase-producingEnterobacteriaceaein rivers and lakes in Switzerland. ESBL-producingEnterobacteriaceaewere detected in 21 (36.2%) of the 58 bodies of water sampled. One river sample tested positive for a carbapenemase-producingKlebsiella pneumoniaesubsp.pneumoniaestrain. Seventy-four individual strains expressing an ESBL phenotype were isolated. Species identification revealed 60Escherichia colistrains, sevenKlebsiella pneumoniaesubsp.pneumoniaestrains, fiveRaoultella planticolastrains, oneEnterobacter cloacaestrain, and oneEnterobacter amnigenusstrain. Three strains were identified as SHV-12 ESBL producers, and 71 strains carried genes encoding CTX-M ESBLs. Of the 71 strains with CTX-M ESBL genes, 8 isolates expressed CTX-M-1, three produced CTX-M-3, 46 produced CTX-M-15, three produced CTX-M-55, one produced CTX-M-79, six produced CTX-M-14, and four produced CTX-M-27. Three of the four CTX-M-27 producers belonged to the multiresistant pandemic sequence typeE. coliB2:ST131 that is strongly associated with potentially severe infections in humans and animals.