Antimicrobial susceptibility of microorganisms isolated from sputum culture of patients with cystic fibrosis: Methicillin-resistant Staphylococcus aureus as a serious concern

Nobandegani, Narges Mazloomi; Mahmoudi, Shima; Pourakbari, Babak; Sadeghi, Reihaneh Hosseinpour; Sani, Mehri Najafi; Farahmand, Fateme; Motamed, Farzaneh; Rafsanjani, Raheleh Nabavizadeh; Mamishi, Setareh

doi:10.1016/j.micpath.2016.09.015

Cited by 15 publications

(9 citation statements)

References 28 publications

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“…Vancomycin, for the moment, remains the first-line intravenous agent for severe MRSA infections, both CA-MRSA and HA-MRSA, and in the present study, we observed no resistance to vancomycin. The same results have been obtained in the studies reported by Mazloomi et al and Ghasemian et al, individually [25,26]. In addition, a vast majority of the MRSA isolates (73%) showed a MDR pattern.…”

Section: Discussionsupporting

confidence: 86%

Toxin production and drug resistance profiles of pediatric methicillin-resistant Staphylococcus aureus isolates in Tehran

Benvidi

Houri

Ghalavand

et al. 2017

J Infect Dev Ctries

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Introduction: Staphylococcus aureus is known to be a major cause of skin and soft tissue infections, pneumonia and invasive diseases. In this study, attempts were made to examine the prevalence of tsst-1, eta, etb, and luk-PV genes among methicillin-resistant S. aureus (MRSA) isolated from children in Tehran. Methodology: In the present cross-sectional study, a total of 100 MRSA were isolated from children who were referred to a pediatric hospital during 11-month period of September 2014 to August 2015. Isolates were identified using biochemical tests and then, using PCR, the isolates were tested for the presence of mecA, tsst-1, eta, etb, and luk-PV genes. Susceptibility of isolates to cefoxitin, penicillin, erythromycin, clindamycin, gentamicin, rifampin, minocycline, co-trimoxazole, linezolid, and vancomycin were evaluated using standard methods. Results: It was found that the MRSA isolates had the greatest resistance to clindamycin (72%) and erythromycin (59%), while the lowest rates of resistance were observed to be related to minocycline (6%) and rifampin (12%). All of isolates were sensitive to vancomycin and linezolid. The mecA gene was detected in all the isolates. Moreover, luk-PV and tsst-1 were detected in 18% and 17% of the isolates, respectively. None of the isolates harbored eta and etb genes. Conclusions: Our data provide specifications about the toxin production status of S. aureus isolates from pediatric children. The current study showed increased resistance to different antibiotics in S. aureus isolates. Therefore, to prevent multi-resistance to other antibiotic classes, it is essential to withhold prescriptions and stop unessential use of available antibiotics.

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Section: Discussionsupporting

confidence: 86%

Toxin production and drug resistance profiles of pediatric methicillin-resistant Staphylococcus aureus isolates in Tehran

Benvidi

Houri

Ghalavand

et al. 2017

J Infect Dev Ctries

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“…Other studies also reported that the most common nosocomial infections were associated with E.coli ( 22 ), P. aeruginosa, and S. aureus ( 23 ). In a study conducted by Mazloomi et al ( 24 ), on 172 specimens collected at a children medical center, the most frequent isolated bacteria were S. aureus and P. aeruginosa.…”

Section: Discussionmentioning

confidence: 99%

Antibacterial activity of amino- and amido- terminated poly (amidoamine)-G6 dendrimer on isolated bacteria from clinical specimens and standard strains

Rastegar

Nazari

Allahabadi

et al. 2017

Med. J. Islam. Republic Iran

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Background: Nanoscale poly (amidoamine) dendrimers have been investigated for their biological demands, but their antibacterial activity has not been widely discovered. Thus, the sixth generation of poly (amidoamine) dendrimer (PAMAM-G6) was synthesized and its antibacterial activities were evaluated on Gram-negative bacteria; P. aeruginosa, E. coli, A. baumannii, S. typhimurium, S. dysenteriae, K. pneumoniae, P. mirabilis, and Gram-positive bacteria, and S.aureus and B. subtilis, which were isolated from different clinical specimens and standard strains of these bacteria. Methods: In this study, 980 specimens including urine (47%), blood (27%), sputum (13%), wounds (8%), and burns (5%) were collected from clinical specimens of 16 hospitals and clinics in city of Sabzevar, Iran. Then, the target bacteria were isolated and identified using standard methods. Minimum inhibitory concentration and minimum bactericidal concentrations against Gram-positive and Gram-negative bacteria were determined according to guidelines described by clinical and laboratory standards institute (CLSI). Standard discs were prepared using 0.025, 0.25, 2.5, and 25 μg/mL concentrations of PAMAM-G6 on Mueller-Hinton agar plates to determinate the zone of inhibition. The cytotoxicity of PAMAM-G6 dendrimer was evaluated in HCT116 cells by MTT assay. Results: The most important isolated bacteria were E. coli (23.65%), S. aureus (24.7%), P. aeruginosa (10.49%), B. subtilis (7.7%), S. typhimurium (8.87%), A. baumannii (7.02%), K. pneumoniae (7.1%), P. mirabilis (6.46%), and S. dysenteriae (3.6%). Moreover, it was found that poly (amidoamine)–G6 exhibited more antibacterial efficacy on standard strains than isolated bacteria from clinical samples (p<0.05). The cytotoxicity of PAMAM-G6 to the cells showed that cytotoxicity depended on the concentration level and exposure time. Conclusion: The PAMAM-G6 dendrimer showed a positive impact on the removal of dominant bacterial isolated from clinical specimens and standard strains.

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“…Reduced pH inhibits the activity of certain endogenous antimicrobials in the lung surfactant leading to bacterial infection. 3,4 This is in contrast to the increased stratum corneum (SC) pH in infected skin and probably related to the different bacterial species and endogenous antimicrobials.…”

Section: Ph In Humansmentioning

confidence: 99%

pH in nature, humans and skin

Proksch

2018

The Journal of Dermatology

377

273

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The pH plays an important physiological role in nature and humans. pH varies from 1 to 8 in human organs with tight regulation in blood and epithelia of barrier organs. The physiological pH of the stratum corneum is 4.1-5.8 and several mechanisms contribute to its formation: filaggrin degradation, fatty acid content, sodium-hydrogen exchanger (NHE1) activation and melanosome release. First, the acidic pH of the stratum corneum was considered to present an antimicrobial barrier preventing colonization (e.g. by Staphylococcus aureus and Malassezia). Later on, it was found that the pH influences skin barrier function, lipid synthesis and aggregation, epidermal differentiation and desquamation. Enzymes of ceramide metabolism (e.g. β-glucocerebrosidase or acid sphingomyelinase) as well as proteases (e.g. chymotryptic enzyme or cathepsin D linked to epidermal differentiation and desquamation) are regulated by the pH. Experimental disruption of the physical barrier leads to an increase of pH, returning to normal levels only after many hours. Inflammatory skin diseases and diseases with an involvement of the epidermis exhibit a disturbed skin barrier and an increased pH. This is known for atopic dermatitis, irritant contact dermatitis, ichthyosis, rosacea and acne, but also for aged and dry skin. Normalizing the pH by acidification through topical treatment helps to establish a physiological microbiota, to repair skin barrier, to induce epidermal differentiation and to reduce inflammation.

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Antimicrobial susceptibility of microorganisms isolated from sputum culture of patients with cystic fibrosis: Methicillin-resistant Staphylococcus aureus as a serious concern

Cited by 15 publications

References 28 publications

Toxin production and drug resistance profiles of pediatric methicillin-resistant Staphylococcus aureus isolates in Tehran

Toxin production and drug resistance profiles of pediatric methicillin-resistant Staphylococcus aureus isolates in Tehran

Antibacterial activity of amino- and amido- terminated poly (amidoamine)-G6 dendrimer on isolated bacteria from clinical specimens and standard strains

pH in nature, humans and skin

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