Incidence of lysogeny, colicinogeny, and drug resistance in enterobacteria isolated from sewage and from rectum of humans and some domesticated species

Abstract

Enterobacteria were isolated by streaking swabs of sewage and rectal swabs from human volunteers and from domesticated animals. Thirty strains of human origin were identified as Escherichia coli. Out of 1,367 rectal isolates of animal origin, 21% were lysogenic (phi'), 29% were colicinogenic (col+), and 7% were col+ phi'. Out of 85 rectal samples more than 60% harbored variable numbers of col+ or phi' bacteria. Lysogens harboring homoimmune prophages were detectable in six out of eight human subjects in sequential samples taken at weekly intervals. Chickens in Hong Kong are fed on antibiotic-containing feeds; the avian isolates contained the highest frequency (98%) of drug-resistant bacteria, whereas only 39% of the bovine and 61% of the human isolates were drug resistant. Transmissible drug resistance was demonstrable in sewage isolates and those from animal sources; the highest frequency (58%) of resistance donors was shown by the avian isolates, and the lowest (9%) was shown by the bovine isolates. Unselected marker analysis has shown that a vast majority of multiply resistant donors of diverse origins are able to transmit multiple resistance.

A phylogenetic approach to assessing the targets of microbial warfare

“…The taxa have varying levels of bacteriocin production that ranges from 3.4 to 26% (Table 1). This range is similar to the levels of bacteriocin production noted from prior surveys of clinical and natural strains of these same taxa (Dhillon & Dhillon, 1981; Bradley, 1991; Riley & Gordon, 1992; Smarda, 1992; Chakraborty & Nag, 1998; Gordon et al. , 1998; Murinda et al.…”

“…Table 2 provides a summary of how many indicator strains were killed per bacteriocin producer, as well as a pooled estimate of percentage killing per taxa for each producer. The levels of killing per taxa range from 1.5 to 6% (Dhillon & Dhillon, 1981; Bradley, 1991; Riley & Gordon, 1992; Smarda, 1992; Chakraborty & Nag, 1998; Gordon et al. , 1998; Murinda et al.…”

LACTOSE NEGATIVE ESCHERICHIA COLI FROM RANGELAND STREAMS: SOURCE, ANTIBIOTIC RESISTANCE, AND COLICINOGENICITY1

“…Many studies of microbiological pollution of water now evaluate antibiotic resistance of isolates with a view toward public health considerations (Armstrong, et a!., 1981(Armstrong, et a!., , 1982Cooke, 1976;Dhillon and Dhillon, 1981;Grabow, et al, 1975;Niemi, et aL, 1983;Shaw and Cabelli, 1980). However, the number and kinds of antibiotics differed in each of those studies.…”

“…However, reviews indicate somewhat ambiguous experimental results (Hardy, 1975(Hardy, , 1978. Dhillon and Dhillon (1981) found that 38 percent of enterobacteria isolated from cattle was colicinogenic and that the colicinogenicity could be transmitted with 22 percent of the isolates. We have found no other reports in the literature with respect to colicinogenicity of bovine E. coii isolates.…”

Is the replication of somatic coliphages in water environments significant?

“…Free phages in different environments can also be produced by lysogenic induction of prophages (Dhillon et al 1976; Weinbauer and Suttle 1996;Jiang and Paul 1998). Moreover many faecal bacteria including E. coli contain inducible prophages in their genome (Dhillon and Dhillon 1981;Schicklmaier et al 1998). However, for the topic of interest in this review the question is whether phages produced by induction of lysogenic strains present in the water environment have any influence on the numbers of somatic coliphages detected by E. coli strains WG5 and CN13.…”