Characterization of a bacterial isolate causing reddish spotting in Sechium edule (Jacq.) Sw.

Abstract

There are few reports of bacterial diseases in the cultivation of chayote Sechium edule (Jacq.) Sw, almost all are attributed to other pathogens, mainly fungi. The objective of the project was to characterize and identify biochemically the pigmented bacterial isolate obtained in  Sechium edule (Jacq.) Sw (chayote). A collection of chayote fruits was carried out in markets of the region, selecting them  according  to  the  symptomatology  that  consists  of  the  observation  of  reddish  spots  on  the superficial level of the fruit. Cuttings were made that were disinfested with 3% sodium hypochlorite to eliminate superficially associated organisms associated with the infection, washed 5 times with sterile distilled water in order to eliminate the hypochlorite. The disinfected samples were macerated in a sterile mortar with a little distilled water, then they were seeded by the extension technique of layered rod dilutions from 10-1 to 10-7 in boxes with nutritive agar and potato dextrose agar. Subsequently, they were incubated at 28 ° C for 24 hours. The purification was carried out by successive reseeding of the  cousin  isolation.  The  exoenzymatic  profile  carried  out  shows  that  this  microorganism  has  8 enzymes: Amylase, esterases, collagenases, phospholipase, lipase, caseinase, DNAse and chitinase. From the bacterial sensitivity test performed with antibiogram, it was observed that the bacteria showed a high degree of inhibition to antibiotics: levofloxacin (LEV), netilmicin (NET), gentamicin (GE), trimetropim or sulfamethoxazole (SXT), amikacin (Ak), and ceftriaxone (CRO). With a high degree of resistance to antibiotics: cefeprime (FEP), cefotaxime (CTX), and  amplicillin  (AM). The tests of morphological, microscopic and biochemical identification, gave like result, that the microorganism problem corresponds to Serratia marcescens.