A pinboard by
Oluwatosin Ajibade

Lecturer II, Adeleke University, Ede, Osun - State, Nigeria. Also a PhD student in Ladoke Akintola University of Technology, Oyo State, Nigeria


Assessment of colistin and carbapenems resistance in clinical isolates of Pseudomonas aeroginosa is the goal of this work. Pseudomonas aeruginosa is a disease causing bacterium which is Gram-negative, rod-shaped, non-fermentative, facultative aerobe belonging to the Gamma Proteobacteria class. Sick people, people with low immunity, Cancer patients, Patients with severe burns, people working in hospital environment usually suffer from pseudomonas infection. Infections ranging from gastrointestinal infections, Urinary tract infections, Dermatitis, Soft tissue infection, Bacteramia, Eye infections, Bone and Joint infection though a variety of systemic infections. Healthy people after exposure to water have been discovered to suffer from pseudomonas infection.Patients with wounds, on breathing machines and catheters stand a high risk of Pseudomonas infections. It is a public health concern that drugs known to cure certain diseases; no longer. Pseudomonas infection has posed resistance to known drugs for its cure also. Different antibiotics are being prescribed by doctors that include Carbapenem and Colistin. Some doctors have a preference for Carbapenem; but this research has shown that Colistin is more effective and efficient to the present day Pseudomonas strains. Constant research in this line must be on, so as to be ahead of disease organisms and make this world devoid of incurable diseases.


Pathotyping and antibiotic resistance of porcine enterovirulent Escherichia coli strains from Switzerland (2014-2015).

Abstract: A total of 131 porcine E. coli were isolated in 2014 and 2015 from the gut of 115 pigs raised in Switzerland and suffering from diarrhea. The isolates were tested for antibiotic resistance, serotypes, virulence factors and genetic diversity. Serotypes were assigned by agglutination tests and virulence genes were identified by polymerase chain reaction (PCR). Antibiotic resistance profile was determined by the measurement of the MIC of 14 antibiotics and by the detection of the corresponding genes using microarray and PCR approaches. Genetic diversity was determined by repetitive palindromic PCR (rep- PCR) revealing a heterogenous population. Half of the E. coli isolates possessing virulence factors could not be assigned to any of the 19 serotypes tested, but contained toxins and adhesins similarly to the sero-typable E. coli isolates. The most prevalent E. coli serotypes found were K88ac (18%), O139:K82 (6%), O141:K85ac (5%), O108:K`V189` (5%), O119:K`V113` (3%) and O157:K`V17` (2%). The combination of toxins EAST-1, STb and LT-I and adhesin F4 characterizing ETEC was the most frequent. The shigatoxin Stx2e (STEC) and intimin Eae (EPEC) were also detected, but less frequently. Seventy percent of the isolates were resistant to at least one antibiotic and 29% were resistant to more than 3 antibiotics. Isolates exhibited resistance to tetracycline (50%) associated to resistance genes tet(A), tet(B) and tet(C), sulfamethoxazole (49%) [sul1, sul2 and sul3], trimethoprim (34%) [dfr], nalidixic acid (29%), ampicillin (26%) [blaTEM-1], gentamicin (17%) [aac(3) -IIc, aac(3) -IVa and aac(3) -VIa], chloramphenicol (17%) [catAI and catAIII], and ciprofloxacin (8%) [mutations in GyrA (S83L) and ParC (S80I)]. All isolates were susceptible to 3rd generation cephalosporins, carbapenems, colistin and tigecycline. Pathogenic E. coli isolates from pigs in Switzerland could frequently not be assigned to a known serotype even if they contained diarrhea-causing virulence factors. They also harbor resistance mechanisms conferring resistance to antibiotics which are commonly used in pig husbandry, except for colistin. A careful identification of the causative agent and antibiotic susceptibility testing is highly recommended for targeted therapy and prudent use of antibiotics.

Pub.: 14 Jul '17, Pinned: 09 Aug '17

Biofilm formation and antibiotic resistance in Klebsiella pneumoniae urinary strains.

Abstract: Multi-drug resistant Klebsiella pneumoniae has become a relevant healthcare-associated pathogen. Capsule, type 1 and 3 fimbriae (mrkA gene), type 2 quorum-sensing system (luxS), synthesis of D-galactan I (wbbM), LPS transport (wzm) and poly-beta-1,6-N-acetyl-D-glucosamine (pgaA) seem involved in K. pneumoniae biofilm. Non-enzymatic antibiotic resistance is related to non-expression or mutation of porins (OmpK35 and OmpK36), and efflux pump (acrB) over-expression. The aim of this study was to analyse some virulence factors of K. pneumoniae isolates, and to evaluate possible correlations between their antibiotic resistance profile and ability to form biofilm.Quantitative biofilm production assay, congo red agar test and string test were performed on 120 isolates clustered in 56 extensively drug resistant (XDR, 40 MDR and 24 susceptible (S)). Nine representative strains were analyzed by real-time RT-PCR for the expression of antibiotic resistance (OmpK35, OmpK36, acrB) and biofilm production genes (mrkA, luxS,, pga, wbbM, wzm) during planktonic and sessile growth. XDR isolates showed a higher ability to form biofilm (91.07%) and to produce polysaccharides (78.57%) when compared to MDR and S strains. In biofilm-growing XDR strains, 7 out of 8 genes were upregulated, with the only exception of OmpK36.XDR strains exhibited phenotypic and genotypic features supporting a significant growth as biofilm.this study produces new findings that highlight a positive correlation between antibiotic resistance profile and biofilm-forming ability in XDR K. pneumoniae strains. These new evidences might contribute to the progress in selection of therapeutic treatments of infections caused by Klebsiella pneumoniae resistant also to the "last line of defense" antibiotics, i.e. carbapenems. This article is protected by copyright. All rights reserved.

Pub.: 22 Jul '17, Pinned: 09 Aug '17