scholarly journals Microdilution Antimicrobial Susceptibilities of Selected Gram-Negative Veterinary Bacterial Isolates

1993 ◽  
Vol 5 (4) ◽  
pp. 541-547 ◽  
Author(s):  
G. E. Burrows ◽  
R. J. Morton ◽  
W. H. Fales

Gram-negative bacterial isolates (63 5) obtained from routine submissions to the Oklahoma Animal Disease Diagnostic Laboratory during 1983–1987 were tested for antimicrobial susceptibility. Minimal inhibitory concentrations (MICs) were determined for the following antimicrobials using commercially prepared microdilution assay materials: ampicillin, cephalothin, chloramphenicol, erythromycin, gentamicin, kanamycin, oxytetracycline, penicillin G, spectinomycin, sulfachlorpyridazine, sulfadimethoxine, and tylosin. Results for isolates from cattle, dogs, horses, and pigs are presented. In only a few instances were differences in MICs apparent among bacterial isolates from different tissues. Aminocyclitol MICs for equine uterine isolates of Klebsiella pneumoniae differed from MICs for isolates from other tissues, and ampicillin, kanamycin, and spectinomycin MICs for bovine fecal isolates of Escherichia coli differed from MICs for isolates obtained from other tissues. In several instances, bimodal distribution of susceptibilities was apparent for ampicillin, kanamycin, and/or oxytetracycline. There was also a bimodal distribution pattern for erythromycin against Pasteurella haemolytica of bovine origin.

2015 ◽  
Vol 2 (2) ◽  
pp. 60-64 ◽  
Author(s):  
KM Shahunja ◽  
Mohammed Abdus Salam ◽  
Tahmeed Ahmed ◽  
Pradip Kumar Bardhan ◽  
Shafiqul Alam Sarker ◽  
...  

Background and Aims: Data on Bacterial isolates from tracheal aspirates in children with severe pneumonia requiring intubation and mechanical ventilation especially in developing countries are very limited. We examined the microbial spectrum of bacteria isolated from tracheal aspirate of those children. The antibiotic susceptibility profiles of those bacteria were also examined.Methods: We evaluated the data of all mechanically ventilated children aged 0-59 months admitted to Intensive Care Unit (ICU) of “Dhaka Hospital” of the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) between August 2009 and July 2013 having their tracheal aspirate culture done. Data were extracted from electronic medical records of the Dhaka Hospital.Results: Among 836 admitted pneumonia children in the ICU, we identified 35 children who fulfilled the inclusion criteria. Among them 34 (97%) had positive bacterial growths: Klebseilla species in 14 (40%), Escherichia coli in 11 (31%), Acinetobacter in 8 (23%) and Streptococcus species in 8 (23%). Additionally, Enterococcus, Staphylococcus aureus, Pseudominas and Proteus species were identified in 6 (17%), 4 (11%), and 2 (6%) of the children respectively. The susceptibility of the gram-negatives, except Klebseilla, to ampicillin, cotrimoxazole, gentamycin, ciprofloxacin, azithromycin, and ceftriaxone ranged from 0- 54%, while that for ceftazidime and amikacin ranged from 12-80%. The sensitivity of Klebseilla to these antibiotics ranged from 0-100%.Conclusions: Our data suggests that gram-negative bacteria, Klebseilla followed by Escherichia coli, and Acenetobacter are the predominant bacteria associated with severe pneumonia in ventilated children. The increased number of infections caused by Gram-negative bacteria is being accompanied by rising rates of multi-drug resistance which underscores the importance of aggressive antimicrobial therapy in the management of such children.Bangladesh Crit Care J September 2014; 2 (2): 60-64


2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Delphine Girlich ◽  
Thierry Naas ◽  
Laurent Dortet

ABSTRACT The dissemination of carbapenemase-producing Enterobacteriaceae (CPE) has led to the increased use of colistin, which has resulted in the emergence of colistin-resistant Enterobacteriaceae worldwide. One of the most threatening scenarios is the dissemination of colistin resistance in CPE, particularly the plasmid-encoded resistance element MCR. Thus, it has now become mandatory to possess reliable media to screen for colistin-resistant Gram-negative bacterial isolates, especially Enterobacteriaceae. In this study, we evaluated the performances of the Superpolymyxin medium (ELITechGroup) and the ChromID Colistin R medium (bioMérieux) to screen for colistin-resistant Enterobacteriaceae from spiked rectal swabs. Stool samples were spiked with a total of 94 enterobacterial isolates (Escherichia coli, Klebsiella pneumoniae, Salmonella enterica, Enterobacter cloacae), including 53 colistin-resistant isolates. ESwabs (Copan Diagnostics) were then inoculated with those spiked fecal suspensions, and culture proceeded as recommended by both manufacturers. The sensitivity of detection of colistin-resistant Enterobacteriaceae was 86.8% (95% confidence interval [95% CI] = 74.0% to 94.0%) using both the Superpolymyxin medium and the ChromID Colistin R plates. Surprisingly, the isolates that were not detected were not the same for both media. The specificities were high for both media, at 97.9% (95% CI = 87.3% to 99.9%) for the Superpolymyxin medium and 100% (95% CI = 90.4% to 100%) for the ChromID Colistin R medium. Both commercially available media, ChromID Colistin R and Superpolymyxin, provide useful tools to screen for colistin-resistant Enterobacteriaceae from patient samples (rectal swabs) regardless of the level and mechanism of colistin resistance.


KYAMC Journal ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 87-90
Author(s):  
Abdullah Akhtar Ahmed ◽  
Nusrat Akhtar Juyee ◽  
SM Ali Hasan

Background: Colistin-resistant Gram-negative bacteria is a rapidly emerging global threatgenerated a sense of public alarm. Objective: To combat this challenge a study was designedto evaluate the fast spreading infections by colistin-resistant pathogens in the tertiary care rural hospital of Bangladesh. Materials and Methods: To study isolation ofpathogenic gram-negative bacilli,clinical sample (n-640) of hospitalized patients of Khwaja Yunus Ali Medical College Hospital in Enayetpur, Bangladesh during the 1st quarter of the year 2019 were used. The bacterial isolates were screened for meropenem and colistin-resistance. Results: A total of 156 bacterial isolates were studied which included Escherichia coli (n-112), Klebsiella pneumoniae (n-14), Pseudomonas aeruginosa (n-27), and Salmonella typhi (n-3). Antibiotic sensitivity testing showed that 32/156(20%) and 119/156 (76%) isolates were resistant to meropenem and colistin, respectively. whereas 50/156 (32%) isolates were resistant to both antibiotics. Escherichia coli, K. pneumoniae, pseudomonas aeruginosa, and Salmonella typhi isolates respectivelywere 112/156 (72%), 14/156 (9%). 27/156 (17%), and 3/156 (2%). Conclusion: Colistin is typically used as salvage therapy, or last-line treatment, for MDR gramnegative infections.But there is worrisome therapeutic scenario in our study finding of colistin resistance is 76% in Gram-negative bacteria of the clinical isolates. The restricted and rational use of colistin drug is the need of hour. KYAMC Journal Vol. 11, No.-2, July 2020, Page 87-90


2000 ◽  
Vol 12 (3) ◽  
pp. 218-223 ◽  
Author(s):  
R. van den Hoven ◽  
J. A. Wagenaar ◽  
R. D. Walker

The in vitro activity of difloxacin against canine bacterial isolates from clinical cases was studied in the United States and The Netherlands. Minimal inhibitory concentrations (MIC), the postantibiotic effect, the effect of pH on antimicrobial activity, and the bacterial killing rate tests were determined according to standard techniques. The MICs of American and Dutch isolates agreed in general. The MICs of the American gram-negative isolates ranged from 0.06 to 2.0 μg/ml, and the MICs of the Dutch gram-negative isolates ranged from 0.016 to 8.0 μg/ml. A few European strains of Proteus mirabilis and Klebsiella pneumoniae had relatively high MICs. Bordetella bronchiseptica also was less susceptible to difloxacin. The MICs of the American gram-positive cocci ranged from 0.125 to 4.0 μg/ml, and the MICs of Dutch isolates ranged from 0.125 to 2.0 μg/ml. Difloxacin induced a concentration-dependent postantibiotic effect that lasted 0.2–3 hours in cultures with Escherichia coli, Staphylococcus intermedius, Streptococcus canis, Proteus spp., and Klebsiella pneumoniae. There was no postantibiotic effect observed against canine Pseudomonas aeruginosa. Decreasing the pH of the medium increased the MIC of Proteus mirabilis for difloxacin. The MICs of Escherichia coli and Klebsiella pneumoniae were lowest at neutral pH and were slightly increased in acid or alkaline media. At a neutral pH, most tested bacterial species were killed at a difloxacin concentration of 4 times the MIC. Similar results were obtained when these same bacteria were tested against enrofloxacin. A Klebsiella pneumoniae strain in an acidic environment was readily killed at difloxacin or enrofloxacin MIC, but at neutral pH the drug concentration had to be raised to 4 times the MIC for a bactericidal effect. After 24 hours of incubation at pH 7.1, difloxacin and enrofloxacin had similar bactericidal activity for all bacteria tested except Staphylococcus intermedius. Against S. intermedius, difloxacin was more bactericidal than enrofloxacin.


2021 ◽  
Vol 910 (1) ◽  
pp. 012027
Author(s):  
Suhair Abed Talaa Al-Sudani ◽  
Alia Saad Al-Hafiz ◽  
Labib Ahmed Kadhim

Abstract The study was conducted to obtain the alcoholic extract of the licorice roots plant and to test its effectiveness against diagnosed bacterial isolates. This research was conducted at the Food Contamination Research Center/Department of Environment and Water/Ministry of Science and Technology. The results showed the following: 1-80% ethyl alcohol was used to obtain the alcoholic extract using a saxolite device, and the activity of the extract was tested against four bacterial isolates diagnosed in the Food Contamination Research Center, which included two gram-negative isolates of Escherichia Coli and Pseudomonas aeruginosa, and two gram-positive isolates of Bacillus Cereus and Staphylococcus aeastureus by a method, in addition to yeast by Diffusion method. The study included two treatments of biscuits with alcoholic extract (A) at a concentration of 10% and compared to the control treatment (B) without any adding and for preservation periods (1, 4, 8, 15, 22) days, and microbial tests were conducted for the biscuits. The alcoholic extract showed a lethal activity to microorganisms and no bacterial cell appeared in the biscuit samples except for the incubation period (22) days for storing biscuits, which recorded the presence of fungi (2) cells/ml. Conducting sensory evaluation of the treatments (A, B) for biscuits where there were no significant differences (P<0.05) for sensory attributes except for flavor and flakes of biscuits.


2020 ◽  
Vol 6 (3) ◽  
pp. 564-569
Author(s):  
Md Habibur Rahman ◽  
Mushtaque Ahmed ◽  
Dayanidhi Sarkar ◽  
Md Asadur Rahman

Urinary tract infection (UTI) is one of the commonest infections encountered by clinicians and despite the widespread availability of antimicrobial agents UTI has become difficult to treat because of appearance pathogens with increasing resistance to antimicrobial agents. The aim and objectives of this study were to determine the pathogens causing UTI and to determine the antibiotic sensitivity status among these isolates in a diagnostic laboratory in Dhaka city. A laboratory based cross sectional survey was conducted in Popular Diagnostic Centre Ltd. Dhanmondi, Dhaka-1205, Bangladesh from July 2016 to December 2016. A total of 553 freshly voided midstream urine samples (10-20 ml) were collected in a wide mouth sterile container from patients and processed in microbiology laboratory to isolate pathogens and antibiotic susceptibility test using standard procedure. Among 553 urine sample, the culture positivity in urine samples was found to be 158 (28.57%) of which 39 (24.70%) were isolated from male patients and 119 (75.30%) from female patients. Escherichia coli (43.67%) were found to be the predominant pathogen followed by Staphylococcus spp. (16.45%), Enterococcus spp. (13.39%), Klebsiella spp. (13.29%), Candida spp. (5.70%), Acinetobacter spp. (4.43%), Psudomonas spp. (3.80%) and Proteus spp. (1.27%). Carbapenem group (Imipenem, Meropenem) were the most effective antibiotic with resistance between 0 and 5.1% of the gram negative isolates and Linezolid and Vancomycin was most effective in gram positive isolates. Nitrofurantoin was most effective both gram negative and gram positive isolates. This study finding showed That Escherichia. coli isolates were the predominant pathogens and showed increasing pattern to the commonly prescribed drugs in private practice that in turn leaves the clinicians with very few alternative options in drug for the treatment of UTIs. Asian J. Med. Biol. Res. September 2020, 6(3): 564-569


2020 ◽  
pp. 73-79

This is the first study that investigated the microbial factor as biomarker in autistic children and discuss roles of this factor in the pathogenesis of autism. The participants in current study were 145 persons, only 50 sample of stool could collected (35 autistic children and 15 healthy children). Autistic children were attended to autism unit at Disabled Hospital in Thi-Qar province, Iraq during the period from January to November 2016. The results showed males (81%) more than female (19%) with ratio 4:1 and also results explain the age group of 3-5 years recorded the highest percentage (41.05%). Distribution of autistic children according to sibling showed six were brotherly with occurrence rate 6.3%. Stool samples were subjected to examination and culture. The total aerobic count of isolated bacteria was 140 isolates. Gram-negative isolates were identified by API Enterobacteriaceae system. The results were Escherichia coli, Enterobacter cloacae, Klebsiella pneumonia, Pseudomonas aeruginosa and Proteus mirabilis with percentage 38.5%, 19.23%, 11.53%,7.69%, and 3.84% respectively. On the other hand, gram positive cocci isolates included Enterococcus faecalis, Staphylococcus aureus and Staph. epidermidis with percentage 11.53%, 4.80% and 2.88% respectively. A significant difference (P≤0.05) was recorded between bacterial isolates. Quantity and quality of isolated bacteria (colony/g *104) were done. E.coli isolates were the highest count with 261*104 colony/g while, Staphylococci epidermidis were recorded the worse colony count with 30*104 colony/g. The quality results showed Escherichia coli the most common gram negative bacterial isolates (38.46%). On the other hand, the highest gram positive cocci isolates were included Enterococcus faecalis (11.53%), with significant difference (P≤0.05) between bacterial isolates. The ability of bacterial isolates to produce histidine decarboxylase was examined on Niven medium. The positive result include colonies with purple halo around them. Only 10 isolates (25%) from all isolates were produce histidine belong to E.coli. On other hand, result of parasite examination explain no parasite in all samples. From this study can conclusion the altered gut microflora may play an essential role in the pathogenesis of autism. Despite the accurate evidence, this etiological heterogeneity is still not recognized by autism researchers, and most studies fail to take it into account.


2017 ◽  
Vol 61 (8) ◽  
Author(s):  
Nayara Helisandra Fedrigo ◽  
Josmar Mazucheli ◽  
James Albiero ◽  
Danielle Rosani Shinohara ◽  
Fernanda Gomes Lodi ◽  
...  

ABSTRACT Fosfomycin is widely used for the treatment of uncomplicated urinary tract infection (UTI), and it has recently been recommended that fosfomycin be used to treat infections caused by multidrug-resistant (MDR) Gram-negative bacilli. Whether urine acidification can improve bacterial susceptibility to fosfomycin oral dosing regimens has not been analyzed. The MIC of fosfomycin for 245 Gram-negative bacterial isolates, consisting of 158 Escherichia coli isolates and 87 Klebsiella isolates which were collected from patients with urinary tract infections, were determined at pH 6.0 and 7.0 using the agar dilution method. Monte Carlo simulation of the urinary fosfomycin area under the concentration-time curve (AUC) after a single oral dose of 3,000 mg fosfomycin and the MIC distribution were used to determine the probability of target attainment (PTA). Fosfomycin was effective against E. coli (MIC90 ≤ 16 μg/ml) but not against Klebsiella spp. (MIC90 > 512 μg/ml). Acidification of the environment increased the susceptibility of 71% of the bacterial isolates and resulted in a statistically significant decrease in bacterial survival. The use of a regimen consisting of a single oral dose of fosfomycin against an E. coli isolate with an MIC of ≤64 mg/liter was able to achieve a PTA of ≥90% for a target pharmacodynamic index (AUC/MIC) of 23 in urine; PTA was not achieved when the MIC was higher than 64 mg/liter. The cumulative fractions of the bacterial responses (CFR) were 99% and 55% against E. coli and Klebsiella spp., respectively, based on simulated drug exposure in urine with an acidic pH of 6.0. A decrease of the pH from 7.0 to 6.0 improved the PTA and CFR of the target pharmacodynamic index in both E. coli and Klebsiella isolates.


1994 ◽  
Vol 6 (3) ◽  
pp. 326-334 ◽  
Author(s):  
Rachel Y. Reams ◽  
Lawrence T. Glickman ◽  
Daniel D. Harrington ◽  
H. Leon Thacker ◽  
Terry L. Bowersock

A retrospective study of 256 cases of naturally acquired Streptococcus suis infections in swine submitted to the Indiana Animal Disease Diagnostic Laboratory from 1985 to 1989 was undertaken to describe the clinical signs, lesions, and coexisting organisms associated with S. suis serotypes 1–8 and 1/2. Infected pigs generally had clinical signs and gross lesions referable to either the respiratory system or to the central nervous system (CNS), but not both. Neurologic signs were inversely related to gross lesions in the respiratory tract ( R2 = −0.19, P = 0.003), as were respiratory signs and gross lesions in the CNS ( R2 = −0.19, P = 0.003). Suppurative bronchopneumonia was the most common gross lesion observed (55.2%, overall). Fibrinous and/or suppurative pleuritis, epicarditis, pericarditis, arthritis, peritonitis, and polyserositis were also reported. In 68% of the pigs, other bacteria in addition to S. suis were isolated. Escherichia coli (35.0%) and Pasteurella multocida (30.0%) were the most commonly recovered bacterial agents. Mycoplasma and viral agents were identified less often, and their role in the development of streptococcosis was difficult to assess. In pigs infected with serotypes 2–5, 7, 8, and 1/2, suppurative meningitis with suppurative or nonsuppurative encephalitis, suppurative bronchopneumonia, fibrinopurulent epicarditis, multifocal myocarditis, and cardiac vasculitis were the most common microscopic lesions observed, whereas pigs infected with serotype 1 generally presented with suppurative meningitis and interstitial pneumonia. Microscopic lesions were morphologically similar among serotypes and were also similar to those reported with other pyogenic bacteria. The distribution of clinical signs and the gross and microscopic lesions in pigs infected with S. suis varied among serotypes. However, these differences were not statistically significant and could not be used to distinguish between the various serotypes. These findings suggest that in pigs infected with S. suis, suppurative or fibrinopurulent inflammation in brain, heart, lungs, and serosae predominates and that bacterial culture is needed to confirm a diagnosis of streptococcosis in swine and to differentiate this disease from those caused by other pyogenic bacteria.


2021 ◽  
Vol 9 (2) ◽  
pp. 80-88
Author(s):  
Sozan M. Nerway ◽  
Muna S. Al-Delaimi

Beta-lactamase producing bacteria have a worldwide distribution with a high degree of prevalence in both community and hospital. Furthermore, multidrug resistant (MDR) and extended spectrum β-lactamases (ESBL) producing bacterial isolates from women patients may limit treatment options available. This study was designed to determine the frequency of bacterial isolates associated with genital tract infection in pregnant women and their antimicrobial resistance profile and to assess the prevalence of extended spectrum β-lactamases producing bacteria. Demonstrating the β-lactamase genes (blaTEM, blaSHV and blaCTX-M) by using polymerase chain reaction (PCR) assay with specific primers, was carried out on patients who were admitted to Maternity and Obstetric Hospital in Duhok city from November 2018 to October 2019. A total of 100 high vaginal swabs were collected from pregnant women patients between the ages 18-45 years. All clinical samples were cultured and standard microbiological methods were used to identify bacterial isolates, then confirmed by Vitek®2 compact automated system. All gram negative bacterial isolates were studied phenotypically and genotypically for extended spectrum β-lactamases-production. Out of 100 vaginal swabs, 88% confirmed positive culture; 90.9% of which were bacterial isolates. From the total bacterial isolates, 38.8% were gram negative bacteria, with a predominant 54.8% Klebsiella pneumoniae followed by Escherichia coli 35.5%. 54.8% of the isolates were characterized as multidrug resistance isolates, 29% isolates were extensive drug resistance, and no pan drug resistance were detected. Among these, the commonest extended spectrum β-lactamases producing isolates were Escherichia coli 81.8% followed by, Klebsiella pneumoniae 58.8%. Extended spectrum β-lactamases-producing isolates have showed significantly higher resistance than non- extended spectrum β-lactamases producing isolates to third and fourth generation cephalosporins. CTX-M was the most common β-lactamase gene 73.7% among extended spectrum β-lactamase producing strains, followed by blaSHV, 57.9% and blaTEM 52.6%, 21.1% had combination of all bla genes, 15.8% had CTX-M only and combination of blaCTX-M with blaSHV and blaTEM. 10.5% among extended spectrum β-lactamases producing isolates carried SHV type only and in combination with TEM type while TEM gene were observed in 5.3%. We concluded that the drug resistant isolates were common, worryingly high and it may limit treatment options available. In this study a high level of the blaCTX-M gene was demonstrated among extended spectrum β-lactamases producing isolates.


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