Letter To The Editor

PEDIATRICS ◽  
1970 ◽  
Vol 46 (2) ◽  
pp. 315-315
Author(s):  
Edward A. Mortimer

We asked Drs. Edward Mortimer and Heinz Eichenwald for their comments. These follow: I agree with Dr. Franciosi that the most practical guide to therapy of bacterial infections with antibiotics currently is the in vitro sensitivity test. There is, of course, some variability in results that depends on many factors, including techniques, which unfortunately may differ from time to time and between laboratories. However, most laboratories currently find about two thirds of E. coli strains sensitive to ampicillin, as noted by Dr. Franciosi.

PEDIATRICS ◽  
1970 ◽  
Vol 46 (2) ◽  
pp. 316-316
Author(s):  
Ralph A. Franciosi

Thank you very much for your letter regarding my letter to the editor and for the responses from Drs. Eichenwald and Mortimer. One interesting development that could be added as an addendum to show the artificial atmosphere of in vitro sensitivity is the finding that since we stopped incubating our sensitivity plates in a CO2 atmosphere, we have noted that only 11.5% of E. coli are resistant to kanamycin and only 8% resistant to ampicillin. Our sensitivity media is Mueller-Hinton with a pH of approximately 7.4. Apparently incubatioii in a CO2 atmosphere, which decreases the pH of the media, interferes with the sensitivity of E. coli in particular to kanamycin and ampicillin.


Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2223
Author(s):  
Moises Bustamante-Torres ◽  
Victor H. Pino-Ramos ◽  
David Romero-Fierro ◽  
Sandra P. Hidalgo-Bonilla ◽  
Héctor Magaña ◽  
...  

The design of new polymeric systems for antimicrobial drug release focused on medical/surgical procedures is of great interest in the biomedical area due to the high prevalence of bacterial infections in patients with wounds or burns. For this reason, in this work, we present a new design of pH-sensitive hydrogels copolymerized by a graft polymerization method (gamma rays), intended for localized prophylactic release of ciprofloxacin and silver nanoparticles (AgNPs) for potential topical bacterial infections. The synthesized hydrogels were copolymerized from acrylic acid (AAc) and agar. Cross-linked hydrogel film formation depended on monomer concentrations and the degree of radiation used (Cobalt-60). The obtained hydrogel films were characterized by attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and mechanical testing. The swelling of the hydrogels was evidenced by the influence of their pH-sensitiveness. The hydrogel was loaded with antimicrobial agents (AgNPs or ciprofloxacin), and their related activity was evaluated. Finally, the antimicrobial activity of biocidal-loaded hydrogel was tested against Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) on in vitro conditions.


1970 ◽  
Vol 6 (1) ◽  
pp. 13-18 ◽  
Author(s):  
MA Zinnah ◽  
MH Haque ◽  
MT Islam ◽  
MT Hossain ◽  
MR Bari ◽  
...  

A total of 100 different E. coli isolates collected from 10 different biological and environmental sources (10 isolates from each source) such as human faces, human urine, cattle, sheep, goat, chicken, duck, pigeon, drain sewage and soil were used for in-vitro drug sensitivity test in the Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh during the period from January to May 2007. Ten different drugs such as Gentamicin (GM), Azithromycin (AZM), Erythromycin (E), Levofloxacin (LVX), Ciprofloxacin (CIP), Tetracycline (TE), Amoxicillin (A), Ampicillin (AP), Nalidixic acid (NA) and Metronidazole (MET) were used in this study. Sensitivity test was carried out by the Kirby-Bauer disc diffusion method as per recommendation of National Committee for Clinical Laboratory Standards and efficacy of a drug was determined by measuring the diameter of the zone of inhibition that results from diffusion of the agent in to the medium surrounding the disc. A high of 80% and 78% E. coli isolates collectively from all the selected sources were sensitive to LVX and CIP respectively, followed by GM (46%), AZM (45%), TE (30%), AP (29%), E (19%), NA (18%) and A (15%). No isolate was sensitive to MET (0%). Incase of resistance, 96% isolates were resistant to MET, followed by A (72%), E (69%), NA (67%), TE (60%), AP (59%), AZM (33%) and GM (32%), CIP (8%) and LVX (5%). A number of isolates showed intermediate reaction to GM (22%), AZM (22%), LVX (15%), NA (15%), CIP (14%), A(13%), AP (12%), E (12%), TE (10%) and MET (4%). This may be an intermediate phase for the conversion of E. coli isolates from sensitive to resistant form. From the research it may be concluded that E. coli infection of different animals and birds and also of human being may be treated effectively with LVX and CIP followed by GM and AZM. Key words: E. coli isolates, levofloxacin, ciprofloxacin, efficacy, resistance DOI = 10.3329/bjvm.v6i1.1332 Bangl. J. Vet. Med. (2008). 6 (1): 13-18


2005 ◽  
Vol 49 (10) ◽  
pp. 4185-4196 ◽  
Author(s):  
Yutaka Ueda ◽  
Katsunori Kanazawa ◽  
Ken Eguchi ◽  
Koji Takemoto ◽  
Yoshiro Eriguchi ◽  
...  

ABSTRACT SM-216601 is a novel parenteral 1β-methylcarbapenem. In agar dilution susceptibility testing, the MIC of SM-216601 for 90% of the methicillin-resistant Staphylococcus aureus (MRSA) strains tested (MIC90) was 2 μg/ml, which was comparable to those of vancomycin and linezolid. SM-216601 was also very potent against Enterococcus faecium, including vancomycin-resistant strains (MIC90 = 8 μg/ml). SM-216601 exhibited potent activity against penicillin-resistant Streptococcus pneumoniae, ampicillin-resistant Haemophilus influenzae, Moraxella catarrhalis, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis, with MIC90s of less than 0.5 μg/ml, and intermediate activity against Citrobacter freundii, Enterobacter cloacae, Serratia marcescens, and Pseudomonas aeruginosa. The therapeutic efficacy of SM-216601 against experimentally induced infections in mice caused by S. aureus, E. faecium, E. coli, and P. aeruginosa reflected its in vitro activity and plasma level. Thus, SM-216601 is a promising candidate for nosocomial bacterial infections caused by a wide range of gram-positive and gram-negative bacteria, including multiresistant pathogens.


2017 ◽  
Vol 14 (2) ◽  
pp. 161-166 ◽  
Author(s):  
M. T. Hasan ◽  
M. R. Islam ◽  
N. S. Runa ◽  
M, N. Hasan ◽  
A. H. M. M. Uddin ◽  
...  

The study was conducted to find out the prevalence of sub-clinical mastitis (SCM) and antibiogram of the causative bacteria in dairy cows at the Sylhet govt. Dairy Farm (SGDF) and Local Farms of Sylhet (LFS) during the period of July2014 to June2015. These farms were selected to assess the predominant types of bacteria involved in causing sub-clinical mastitis and to know the in vitro antibiotic sensitivity spectrum of these bacterial isolates against the commonly used antibiotics and to study the economic effects due to SCM. Use of California Mastitis Test (CMT) for the detection of sub-clinical mastitis showed 42out of 100 samples were test positive, among which +(Trace) 22.0%, ++(Distinct) 12.0%, +++(Strong) 3.0%, ±(Doubtful) 5.0%.  Bacteriological examination of milk samples of 100 milch cows (400 quarters) revealed that 42 cows (42.0%) had suffering from SCM with different bacterial infection with 95% confidence limit was 32.1574-51.8426. Among 42 positive samples31 (31.0%) cows had mono-bacterial infection and 11 (11.0%) cows had mixed bacterial infections. Statistical analysis of the result of single and mixed bacterial infections in the milk of apparently healthy milch cows revealed that the single infection was significantly (P < 0.05) higher than mixed bacterial infection. Of the 31 mono-bacterial isolates, of which 23 (23.0%) isolates were Staphylococci, 3 (3.0%) isolates were Escherichia coli, 5 (5.0%) isolated Streptococcus spp. The 11 cows had mixed infection, of which 5 had Staphylococcus spp. + Streptococcus spp., 3 had E. coli + Staphylococcus spp., and 3 had Streptococcus spp. + E. coli. Of 42 positive cases of SCM Staphylococcus spp. isolated from 23 samples. Among these 23 positive samples 13 obtained from SGDF (37.14%) and 10 obtained from LFS (15.38%). Escherichia coli isolated from 3 samples. Among these 3 positive samples 3 obtained from LFS (4.62%). Streptococcus spp. isolated from 5 samples. Among these 5 positive samples 1 obtained from SGDF (2.86%) and 4 obtained from LFS (6.15%). Ceftriaxone, ciprofloxacin and gentamicin were the best drug for treating sub-clinical mastitis.


1997 ◽  
Vol 41 (10) ◽  
pp. 2209-2213 ◽  
Author(s):  
J H Kim ◽  
J A Kang ◽  
Y G Kim ◽  
J W Kim ◽  
J H Lee ◽  
...  

CFC-222 is a novel fluoroquinolone containing a C-7 bicyclic amine moiety with potent antibacterial activities against gram-positive, gram-negative, and anaerobic organisms. We compared the in vitro and in vivo activities of CFC-222 with those of ciprofloxacin, ofloxacin, and lomefloxacin. CFC-222 was more active than the other fluoroquinolones tested against gram-positive bacteria. CFC-222 was particularly active against Streptococcus pneumoniae (MIC at which 90% of isolates are inhibited [MIC90], 0.2 microg/ml), Staphylococcus aureus (MIC90, 0.2 microg/ml for ciprofloxacin-susceptible strains), and Enterococcus faecalis (MIC90, 0.39 microg/ml). Against Escherichia coli and other members of the family Enterobacteriaceae, CFC-222 was slightly less active than ciprofloxacin (MIC90s for E. coli, 0.1 and 0.025 microg/ml, respectively). The in vitro activity of CFC-222 was not influenced by inoculum size, medium composition, or the presence of horse serum. However, its activity was decreased significantly by a change in the pH of the medium from 7.0 to 6.0, as was the case for the other quinolones tested. The in vivo protective efficacy of CFC-222 by oral administration was greater than those of the other quinolones tested in a mouse model of intraperitoneally inoculated systemic infection caused by S. aureus. CFC-222 exhibited efficacy comparable to that of ciprofloxacin in the same model of infection caused by gram-negative organisms, such as E. coli and Klebsiella pneumoniae. In this infection model, CFC-222 was slightly less active than ciprofloxacin against Pseudomonas aeruginosa. These results suggest that CFC-222 may be a promising therapeutic agent in various bacterial infections.


2016 ◽  
Vol 22 (6) ◽  
pp. 444-451 ◽  
Author(s):  
Shin Morioka ◽  
Kiyomi Nigorikawa ◽  
Junko Sasaki ◽  
Kaoru Hazeki ◽  
Yoshihiro Kasuu ◽  
...  

Phosphatidylinositol 3-kinase (PI3K)/Akt signaling has been implicated in the anti-inflammatory response in a mouse model of endotoxemia and sepsis. The present study focused on the role of inositol polyphosphate-4-phosphatase type I (Inpp4a), which dephosphorylates PtdIns(3,4)P2 to PtdIns(3)P, in bacterial infections. We prepared myeloid cell-specific Inpp4a-conditional knockout mice. Macrophages from these mice showed increased Akt phosphorylation and reduced production of inflammatory cytokines in response to LPS or Escherichia coli in vitro. The Inpp4a knockout mice survived for a shorter time than wild type mice after i.p. infection with E. coli, with less production of inflammatory cytokines. Additionally, E. coli clearance from blood and lung was significantly impaired in the knockout mice. A likely mechanism is that the Inpp4a-catalyzed dephosphorylation of PtdIns(3,4)P2 down-regulates Akt pathways, which, in turn, increases the production of inflammatory mediators. This mechanism at least fits the decreased E. coli clearance and short survival in the Inpp4a knockout mice.


2012 ◽  
Vol 56 (6) ◽  
pp. 3309-3317 ◽  
Author(s):  
Sheng-An Li ◽  
Wen-Hui Lee ◽  
Yun Zhang

ABSTRACTAntimicrobial peptides (AMPs) have been considered alternatives to conventional antibiotics for drug-resistant bacterial infections. However, their comparatively high toxicity toward eukaryotic cells and poor efficacyin vivohamper their clinical application. OH-CATH30, a novel cathelicidin peptide deduced from the king cobra, possesses potent antibacterial activityin vitro. The objective of this study is to evaluate the efficacy of OH-CATH30 and its analog OH-CM6 against drug-resistant bacteriain vitroandin vivo. The MICs of OH-CATH30 and OH-CM6 ranged from 1.56 to 12.5 μg/ml against drug-resistant clinical isolates of several pathogenic species, includingEscherichia coli,Pseudomonas aeruginosa, and methicillin-resistantStaphylococcus aureus. The MICs of OH-CATH30 and OH-CM6 were slightly altered in the presence of 25% human serum. OH-CATH30 and OH-CM6 killedE. coliquickly (within 60 min) by disrupting the bacterial cytoplasmic membrane. Importantly, the 50% lethal doses (LD50) of OH-CATH30 and OH-CM6 in mice following intraperitoneal (i.p.) injection were 120 mg/kg of body weight and 100 mg/kg, respectively, and no death was observed at any dose up to 160 mg/kg following subcutaneous (s.c.) injection. Moreover, 10 mg/kg OH-CATH30 or OH-CM6 significantly decreased the bacterial counts as well as the inflammatory response in a mouse thigh infection model and rescued infected mice in a bacteremia model induced by drug-resistantE. coli. Taken together, our findings demonstrate that the natural cathelicidin peptide OH-CATH30 and its analogs exhibit relatively low toxicity and potent efficacy in mouse models, indicating that they may have therapeutic potential against the systemic infections caused by drug-resistant bacteria.


Sign in / Sign up

Export Citation Format

Share Document