scholarly journals Phenotypic properties of R factors ofPseudomonas aeruginosa:R factors readily transferable betweenPseudomonasand the Enterobacteriaceae

1974 ◽  
Vol 23 (3) ◽  
pp. 239-250 ◽  
Author(s):  
P. M. Chandler ◽  
V. Krishnapillai

SUMMARYR factors have been demonstrated in multiply drug resistant strains of enterobacteria andPseudomonas aeruginosain a Birmingham hospital (Lowburyet al.1969; Ingram, Richmond & Sykes, 1973). A comparative genetic analysis of these R factors has been initiated on the basis of a variety of phenotypic characteristics. This paper describes the properties of R factors derived from strains which could transfer multiple drug resistance to the recipient speciesP. aeruginosa, Escherichia coli, Shigella flexneriandSalmonella typhimurium. Two types of R factor could be recognized phenotypically. The single group 1 R factor, R18–1 which is probably the same as RPl-1 (Ingramet al.1972) was different to the group 2 R factors in many respects, including host range, R factor-specific phage plating, cellular location, drug resistance pattern, and stability. The group 2 R factors were found to be very similar to RPl (Grinstedet al.1972) and R1822 (Olsen & Shipley, 1973) with respect to their wide host range, plating of a sex specific phage, extrachromosomal location, and drug resistance pattern. Compatibility was shown between the group 1 R factor and a group 2 R factor, providing additional evidence for significant genetic differences.

1974 ◽  
Vol 23 (3) ◽  
pp. 251-257 ◽  
Author(s):  
P. M. Chandler ◽  
V. Krishnapillai

SUMMARYA study was made of the R factors from two multiply drug resistant wild type isolates ofPseudomonas aeruginosafrom a Birmingham hospital (Lowburyet al.1969) from which, in contrast to other strains from the same source (Chandler & Krishnapillai, 1974a), drug resistance was not transferable toEscherichia coliK12 orSalmonella typhimurium. Transfer of drug resistance occurred at a low frequency toShigella flexneri, although drug resistance in this species was subsequently non-transferable.InP. aeruginosathere are several features of these two R factors which distinguish them from the group 1 and 2 R factors described previously (Chandler & Krishnapillai, 1974a). Although coding for resistance to neomycin and tetracycline, they did not express this resistance in two strains ofP. aeruginosaexamined, in contrast to the wild type strains they were isolated in.The control of transfer of the two R factors is different to the group 1 and 2 R factors in that derepression of transfer could be demonstrated following physiological treatments or mutagenesis. The R factors of this third group were compatible with the group 2 R factors, but did not repress their pilus synthesis on the basis of R factor specific phage plating.


2010 ◽  
Vol 4 (08) ◽  
pp. 477-483 ◽  
Author(s):  
Bhoj Raj Singh ◽  
Meenu Agarwal ◽  
Mudit Chandra ◽  
Meena Verma ◽  
Gautam Sharma ◽  
...  

Background: Buffalo is the major source of animal protein in south-east Asia, including India; therefore, the presence of multiple drug resistance in Salmonella strains of buffalo meat and milk products is of immense public health concern. Methodology: Forty-six strains of Salmonella enterica subspecies enterica  belonging to eight serovars (S. Anatum, 13; S. Weltevreden, 13; S. Rostock, 6; S. Typhimurium, 5; S. Gallinarum, 5; S. Stockholm, 1; S. Dublin, 1; and S. Orion, 2), isolated from buffalo meat and diseased buffaloes were studied for their antibiotic sensitivity and plasmid profile. Results: All except six strains of Salmonella had one or more plasmids. Virulence plasmid of ~35MdA was present in 39 isolates while 19 strains had one to six additional plasmids with molecular weight ranging from 1 Mda > 35 Mda. A plasmid-free S. Anatum strain was resistant to seven drugs including fluoroquinolones, while strains having six to seven plasmids were resistant to fewer antimicrobial drugs. One S. Anatum isolate, resistant to 11 antibiotics, had only one plasmid. Eight serovars of Salmonella could be divided into 28 resistotypes on the basis of antimicrobial sensitivity assay. Most strains were resistant to streptomycin (84.8%) followed by kanamycin (58.7%), gentamicin (52.2%), ampicillin (50%) and oxytetracycline (50%). Few strains were resistant to cefotaxime (2.2%), amoxycillin (2.2%) and newer fluoroquinolones (6.5%). Conclusion: Multiple drug resistance was common among Salmonella isolates of buffalo origin, particularly against aminoglycosides, oxytetracycin, ampicillin and cephalexin. Presence of plasmids is not mandatory for occurrence of multiple drug resistance in S. enterica strains.


Author(s):  
S.V. Singh ◽  
J.P. Singh ◽  
Vibha Yadav ◽  
Sandeep Kumar Yadav ◽  
Ramakant . ◽  
...  

Background: Mastitis is a problem of dairy animals including buffaloes. Treatment failure has become a common problem and the most cited reason is antibiotic resistance. The paper presents the scenario of antibiotic resistance with special reference to multi drug resistance pattern. Methods: Microbiological assay of mastitis affected 48 milk samples was carried out using standard protocols to establish the prevalence of mastitis caused by E. coli and S. aureus. Antibiotic sensitivity test was carried out against these organisms and the whole milk culture for commonly used antibiotics. The drug resistance pattern was established. Result: The overall prevalence of mastitis was 20%. The prevalence of E. coli and S. aureus was 29.17% and 54.17% respectively. The antibiotic sensitivity revealed that E.coli isolates were 100% susceptible to tetracycline, gentamicin, enrofloxacin and streptopenicillin followed by Ceftriaxone and sulbactum combination and streptomycin (92.86%) and ceftriaxone and methicillin (85.71%). The isolates of S. aureus were 100% sensitive to only two antibiotics gentamicin and streptopenicillin. The antibiogram of whole milk culture revealed maximum susceptibility to enrofloxacin, gentamicin and streptopeniciliin (95.83% each). Multiple drug resistance has been observed in this study.


2014 ◽  
Vol 143 (3) ◽  
pp. 470-477 ◽  
Author(s):  
D. BHATTACHARYA ◽  
H. BHATTACHARYA ◽  
D. S. SAYI ◽  
A. P. BHARADWAJ ◽  
M. SINGHANIA ◽  
...  

SUMMARYThis study is a part of the surveillance study on childhood diarrhoea in the Andaman and Nicobar Islands; here we report the drug resistance pattern of recent isolates ofShigellaspp. (2006–2011) obtained as part of that study and compare it with that ofShigellaisolates obtained earlier during 2000–2005. During 2006–2011, stool samples from paediatric diarrhoea patients were collected and processed for isolation and identification ofShigellaspp. Susceptibility to 22 antimicrobial drugs was tested and minimum inhibitory concentrations were determined for third-generation cephalosporins, quinolones, amoxicillin-clavulanic acid combinations and gentamicin. A wide spectrum of antibiotic resistance was observed in theShigellastrains obtained during 2006–2011. The proportions of resistant strains showed an increase from 2000–2005 to 2006–2011 in 20/22 antibiotics tested. The number of drug resistance patterns increased from 13 in 2000–2005 to 43 in 2006–2011. Resistance to newer generation fluoroquinolones, third-generation cephalosporins and augmentin, which was not observed during 2000–2005, appeared during 2006–2011. The frequency of resistance inShigellaisolates has increased substantially between 2000–2006 and 2006–2011, with a wide spectrum of resistance. At present, the option for antimicrobial therapy in shigellosis in Andaman is limited to a small number of drugs.


Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1042
Author(s):  
Pawan Parajuli ◽  
Bui Quang Minh ◽  
Naresh K. Verma

Bacillary dysentery caused by Shigella flexneri is a major cause of under-five mortality in developing countries, where a novel S. flexneri serotype 1c has become very common since the 1980s. However, the origin and diversification of serotype 1c remain poorly understood. To understand the evolution of serotype 1c and their antimicrobial resistance, we sequenced and analyzed the whole-genome of 85 clinical isolates from the United Kingdom, Egypt, Bangladesh, Vietnam, and Japan belonging to serotype 1c and related serotypes of 1a, 1b and Y/Yv. We identified up to three distinct O-antigen modifying genes in S. flexneri 1c strains, which were acquired from three different bacteriophages. Our analysis shows that S. flexneri 1c strains have originated from serotype 1a and serotype 1b strains after the acquisition of bacteriophage-encoding gtrIc operon. The maximum-likelihood phylogenetic analysis using core genes suggests two distinct S. flexneri 1c lineages, one specific to Bangladesh, which originated from ancestral serotype 1a strains and the other from the United Kingdom, Egypt, and Vietnam originated from ancestral serotype 1b strains. We also identified 63 isolates containing multiple drug-resistant genes in them conferring resistance against streptomycin, sulfonamide, quinolone, trimethoprim, tetracycline, chloramphenicol, and beta-lactamase. Furthermore, antibiotic susceptibility assays showed 83 (97.6%) isolates as either complete or intermediate resistance to the WHO-recommended first- and second-line drugs. This changing drug resistance pattern demonstrates the urgent need for drug resistance surveillance and renewed treatment guidelines.


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