Quinolones Resistance And R-Plasmids Of Clinical Isolates Of Pseudomonas Species

Background: There has been reported incidence in the emergence of Quinolones resistance in clinical isolates in Nigeria and the level in resistance has been on the increase. Objective: To determine the antimicrobial resistance patterns and plasmids profiles of 67 clinical Pseudomonas species from a teaching hospital and diagnostic laboratory in Nigeria. Materials and methods: The Pseudomonas species were identified and confirmed by standard procedures. The antibiotic susceptibility patterns were determined by Agar Disk Diffusion method. Plasmids DNA was isolated, separated and stained as previously described. Results: 30 of these clinical isolates were found to be resistant to 6 quinolones antibiotics with ciprofloxacin being the highest [52.24%] and norfloxacin [38.81%] the lowest. All the strains that were resistant to any antimicrobial agents were also resistant to ciprofloxacin. A total of 54 plasmids ranging in molecular sizes from 3.55kb to 19.95kb were extracted from the resistant strains and grouped into 5 plasmid profiles. Transformation experiment revealed that 66.67% of the resistant strains carried a common R plasmid of size 15.85kb. Plasmid mediated resistant to ciprofloxacin and levofloxacin were found. Conclusion: The results highlighted diverse plasmids profile and wide spread antimicrobial resistance patterns of some clinical Pseudomonas species from Nigeria. Keywords: Quinolones, R-plasmids, Pseudomonas.Sudan Journal of Medical Sciences Vol. 3 (2) 2008: pp. 139-14

Comparative Analysis Of Antibiotic Resistance And R-Plasmids Of Staphylococcus aureus Isolates From Human And Dog Samples

Bacterial resistance to antibiotics constitutes a major cause of failure in the treatment of bacterial infections. The genetic exchange of plasmids containing antibiotic resistant determinants between bacteria is believed to play a critical role in the evolution of antibiotics resistant bacteria and this has been shown in S. aureus. This study was therefore carried out to investigate the nature of plasmids that determine antibiotic resistance in Staphylococcus aureus isolates from man and animal. Thirty multiply drug resistant S. aureus isolates from a total of 147 apparently healthy humans and dogs, as well as from clinical cases were determined by antibiotic susceptibility test using the standard disc agar diffusion method. Plasmid isolation was carried out by the alkaline lysis method of Birnboim and Dolly. Electrophoresis as well as the transformation experiment was done.The result showed that no particular sensitivity pattern or plasmid profile  can be ascribed to either human or animal sources of isolates. Two isolates from a domestic dog and its owner (human) were observed to have identical plasmid profile and almost the same antibiogram. 23.130 kbp and 25.119 kbp plasmids that were responsible for amoxycilin resistance were transferred. In conclusion, the genetic basis of antibiotic resistance by S. aureus in our locality was found to be partly plasmid mediated. Plasmid analysis, in conjunction with the antibiogram is valuable in differentiating multiple resistant S. aureus.Furthermore, domestic pet animals were found to be reservoirs and potential risk factors in the transfer of multiply antibiotic resistant S. aureus and their R-plasmids to antibiotic susceptible S. aureus and other bacteria

In-Vitro efficacy of antimicrobial agents used in the treatment of bacterial eye infections in Ibadan, Nigeria

Failure to cure eye infections, and reduced potency in topical antimicrobials had been observed in South Western Nigeria, this study sought to evaluate in vitro, the efficacy of antimicrobial agents in the treatment of ocular infections. A total of 46 ocular bacterial isolates were recovered from the diagnostic laboratory of the University College Hospital, Ibadan, from conjunctival swabs of patients having underlying eye diseases (Cataracts, glaucoma and esotrapia), and from patients presenting with other symptoms of eye infections. The pathogens incriminated were Staphylococcus aureus (73.5%), Coagulase negative Staphylococci (13.3%), Klebsiella species (10.3%), and Pseudomonas aeruginosa (2.0%). Disc diffusion tests (Bauer-Kirby method) were carried out using ciprofloxacin, gentamicin, chloramphenicol, erythromycin, augmentin, cefuroxime and levofloxacin. Broth dilution techniques were thereafter performed using gentamicin, chloramphenicol and ciprofloxacin. The microlide- erythromycin was 63.0% efficacious, augmentin and cefuroxime showed 71.1% and 76% efficacy. Minimum inhibitory concentrations (MIC) of commonly used topical antibiotics however showed different levels of resistance. Resistance to the aminoglycosides was marked, yielding 53.4% with MIC50= 8, MIC90 > 256, Resistance to chloramphenicol was even more marked 69.6% with MIC50= 16, MIC90= 64, the fluoroquinolones showed high efficacy- levofloxacin and ciprofloxacin showed 93.4% and 82.6% susceptibility respectively with MIC50 < 0.5, though slightly demonstrable resistance was observed (MIC90= 8). The study thus recommends the discontinuation of empirical therapy by physicians in order to stem the tide of resistance; it justifies the inclusion of the fluoroquinolones in susceptibility testing of ocular bacterial isolates, and its first line of choice if cure is warranted.doi: 10.4314/ajcem.v12i3.

Pattern of Microbial Colonization of the Vagina of Diabetics in Ibadan, Nigeria

The pattern of microbial flora of the vagina of diabetics was studied, to advise on empirical regimen for the treatment of sepsis in diabetics with the lower genital tract as source. In 2003, microscopy, culture and sensitivity of high vaginal swabs from 60 consecutive non-insulin-dependent diabetics and 20 non-diabetics attending Oluyoro Catholic Hospital, Ibadan were done. The fasting plasma glucose was estimated. The prevalence of micro-organisms decreased with duration of diabetes. The isolates were Gardnerella vaginalis, Candida species, Staphylococcus epidermidis, Klebsiella species, Enterococcus faecalis, and viridans Streptococcus. Klebsiella species and Escherichia coli were incriminated in Gram negative bacilli (GNB) bacteraemia in diabetics in this environment. In addition to metronidazole, ceftazidime or ceftriazone should be used as first line drugs, while the quinolones should be reserved for the treatment of sepsis in diabetics where lower genital tract is the likely source of infection

In vitro resistance of gram-negative enteric bacilli from wound infections to honey

Letter to the Edito

Quinolones resistance and R-plasmids of some gram negative enteric bacilli

Out of the two hundred and sixty bacteria isolates from clinical specimens obtained from different body sites at the University College Hospital Ibadan, 166 belonged to the family of Enterobacteriaceae and Pseudomonaceae. The isolated gram-negative enteric bacilli consist of Escherichia coli (22), Klebsiella species (65), Proteus species (20), Salmonella typhi (2), Pseudomonas aeruginosa (39) and Pseudomonas species (18). Among the antimicrobial agents tested, high resistance was found with ofloxacin 44.0%, followed by pefloxacin 30.1% and ciprofloxacin 21.7%. Ciprofloxacin has the lowest MIC of 2 – 32 &mu;g/ml while ofloxacin has the highest 64 &mu;g/ml. Of the 166 strains, 44 were resistant to most of the antimicrobial agents tested. All the strains that were resistant to any antimicrobial agents were also resistant to ofloxacin. A total of 27 plasmids ranging in molecular sizes from 6.6.kb to 17.4kb were extracted from the resistant strains and grouped into 5 plasmid profiles. Transformation experiment revealed that 59.2% of the resistant strains carried a common R-plasmid of size 10.7kb. Plasmid-mediated resistance to ciprofloxacin and pefloxacin was found. Klebsiella species harboured the highest number of R-plasmids with 8, followed by Pseudomonas aeruginosa with 4. Afr. J. Clin. Exper. Microbiol. Vol.6(1) 2005: 14-2

High levels of multidrug resistance in clinical isolates of Gram-negative pathogens from Nigeria.

International audienceIn Nigeria, quinolones and β-lactam antibiotics are widely used to treat bacterial infections. This study aimed to identify the prevalence of resistance to these drugs and to determine the mechanisms of resistance to these agents. In total, 134 non-duplicate, Gram-negative enteric isolates of 13 species from different hospitals were investigated for susceptibility to a panel of antibiotics, carriage of plasmid-mediated quinolone and β-lactam resistance genes, production of extended-spectrum β-lactamases (ESBLs), and mutations within topoisomerase genes. The level of resistance to all antibiotics tested was extremely high, with minimum inhibitory concentrations for 90% of the organisms (MIC values) of ≥256μg/mL for all drugs. Of the 134 isolates, 92 had mutations within the quinolone resistance-determining region (QRDR) of or within and . In addition, the plasmid-mediated quinolone resistance genes , , and were identified. The allele, which has previously only been found in isolates from China, was identified in two isolates and one isolate. Of the 134 isolates, 23 (17.2%) carried , 11 (8.2%) carried a variant and 5 (3.7%) were positive for . Twenty-eight isolates (20.9%) produced ESBL variants, with a CTX-M variant being carried by 25 isolates (18.7%). In addition, six isolates (4.5%) carried variants [ACT-1 (1 isolate), DHA-1 (4 isolates) and CMY-2 (1 isolate)]. This study demonstrates a very high level of multidrug resistance amongst Gram-negative enteric bacilli isolated from different sites from patients in Nigerian hospitals as well as the presence of a variety of plasmid-associated resistance genes, including some identified from Africa for the first time

Co-agulase Negative Staphylococcus Distribution in Clinical Sample in a Tertiary Hospital in Ibadan, Nigeria

Numerous researchers have described the isolation of coagulase-negative staphylococci especially S. epidermidis, and the association of the bacteria with clinical disease. In this study we determined the distribution of coagulase-negative staphylococci isolated from clinical samples in tertiary hospital. One hundred and fifteen repeat CoNS isolates were obtained from 607 various clinical specimens using standard precedures; 97 (84.3%) were strains of S. epidermidis while 18 (15.7%) were S. Saprophyticus. The highest number of isolates of CoNS were from Blood culture, 75 out of 115 strains (65.2%) and 68.0% were strains of S. epidermidis. Septicaemia had the highest prevalence of CoNS, 31.4%; followed by endocraditis, 25.0%. The least was found in otits and pyrexia of unkonwn origin, 7.4% and 8.3% respectively. All the CoNS strains were resistant to one or more of the eleven antimicrobial agents used. The frequancy of susceptibility to fluoroquinolones was the highest; ofloxacin(81.7%), ciprofloxacin (77.4%). The least susceptibility was found in tetracycline; 20.0%. No isolate was sensitive to cotrimoxazole. However, S. epidermidis had a greater percentage of strains susceptibleto the quinolones; ofloxacin; 84.0% and ciprofloxacin; 80.0% than the S. saprohyticus, ofloxacin; 67.0% and ciprofloxacin; 44.0%. The distribution of CoNS in clinical specimens obtained from hospital enivronment in this study has shown that CoNS have become an important pathogen, therefore antimicrobial susceptibility tests should be carried out as a guide for therapy and to control development of resistant strains