Antimicrobial-ResistantStreptococcus pneumoniaein Canadian Hospitals: Results from the 2007 CANWARD Study

BACKGROUND: The Canadian Ward Surveillance Study (CANWARD 2007) tested isolates collected from January to December 2007 from 12 Canadian hospitals to a range of antimicrobial agents. The present paper focuses on antimicrobial resistance inStreptococcus pneumoniaein Canadian hospitals, with an emphasis on macrolide resistance. MEtHODS: Minimum inhibitory concentrations of antimicrobial agents were determined using the broth microdilution method and interpreted according to Clinical and Laboratory Standards Institute breakpoints. Macrolide-nonsusceptible strains (clarithromycin minimum inhibitory concentrations 0.5 μg/mL or greater) were analyzed by multiplex polymerase chain reaction for the presence ofmefA andermB genes. RESULTS:S pneumoniaerepresented 9.0% (706 of 7881) of all isolates collected in CANWARD 2007. Of the 706S pneumoniaeisolates collected, 33.1% (234) were from blood and 66.9% (472) were from respiratory specimens. The overall resistance (resistant and intermediate) rates forS pneumoniaeisolated from respiratory and blood specimens, respectively, were: penicillin (23.9%, 14.4%), clarithromycin (22.1%, 12.6%), trimethoprim-sulfamethoxazole (14.7%, 11.5%), doxycycline (7.8%, 5.1%) and clindamycin (7.1%, 3.3%). Multidrug resistance (resistance to penicillin, clarithromycin and trimethoprimsulfamethoxazole) accounted for 2% (n=9) and 0.5% (n=1) of respiratory and blood isolates, respectively. Susceptibility of 95% or greater was found with amoxicillin-clavulanic acid (99.5%, 99.3%), ceftriaxone (99.5%, 100%), cefuroxime (95.0%, 96.8%), ertapenem (99.8%, 100%), meropenem (96.1%, 99.5%) and levofloxacin (99.1%, 100%) for respiratory and blood specimens, respectively. No resistance to vancomycin, tigecycline, cethromycin or telithromycin was found. mefA was present in 53.6% (52 of 97) of respiratory and 59.3% (16 of 27) of blood macrolide-nonsusceptibleS pneumoniae, while ermB was present in 38.1% (37 of 97) of respiratory and 37% (10 of 27) of blood isolates. Eight of 97 (8.2%) respiratory and one of 27 (3.7%) blood isolates contained both mefA and ermB genes. CONCLUSIONS:S pneumoniaeis a common organism isolated from clinical specimens in Canadian hospitals. Resistance was highest to penicillin and clarithromycin, while ceftriaxone and levofloxacin susceptibility were both greater than 99%. No isolates resistant to vancomycin, tigecycline, linezolid or the ketolides were found. Resistance rates were higher among respiratory tract isolates ofS pneumoniaethan among blood isolates. Macrolide efflux,mefA, was the predominant mechanism of macrolide resistance among both respiratory and blood clarithromycin-nonsusceptible isolates.

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Minimum inhibitory concentrations of commonly used antibiotics against Helicobacter Pylori: A multicenter study in South China

PLoS ONE ◽

10.1371/journal.pone.0256225 ◽

2021 ◽

Vol 16 (9) ◽

pp. e0256225

Author(s):

Xueping Huang ◽

Yuan Liu ◽

Zhihui Lin ◽

Baihe Wu ◽

Gaohui Nong ◽

...

Keyword(s):

Helicobacter Pylori ◽

South China ◽

Resistance Rate ◽

Minimum Inhibitory Concentrations ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Gastric Biopsies ◽

Overall Resistance ◽

Resistance Rates

Aim To determine the minimum inhibitory concentrations (MICs) of commonly used antibiotics against Helicobacter Pylori (H. pylori) in South China and compare their resistance rates by using EUCAST breakpoints and other breakpoints. Methods Patients who had not previously received H. pylori treatment in clinical centers in South China were enrolled in this study from 2017 to 2020. Gastric biopsies were obtained for H. pylori culture. The MICs of amoxicillin (AMX), clarithromycin (CLA), metronidazole (MTZ), levofloxacin (LEV), tetracycline (TET) and furazolidone (FZD) were tested by broth microdilution method and assessed by two different breakpoints. ATCC43504 standard strain served as a control. Results A total of 208 H. pylori strains were isolated from patients’ biopsy samples. The MICs of AMX, CLA, MTZ, LEV, TET and FZD for H. pylori were 0.0156-256mg/L (MIC50 0.125mg/L, MIC90 4mg/L), 0.0156- >256 mg/L (MIC50 0.0312mg/L, MIC90 64mg/L), 0.0156- >256mg/L (MIC50 8mg/L, MIC90 256mg/L), 0.0156-256mg/L (MIC50 0.25mg/L, MIC90 16mg/L), 0.0156-256mg/L (MIC50 0.0625mg/L, MIC90 4mg/L), and 0.0156- >256mg/L (MIC50 0.0312mg/L, MIC90 2mg/L), respectively. The MICs of AMX, CLA, MTZ, LEV, TET and FZD for ATCC43504 strain were 0.25mg/L, 0.0625mg/L, 64mg/L, 0.5mg/L, 1mg/L and 0.25mg/L, respectively. The resistance rate of FZD was 11.05%. The overall resistance rates according to EUCAST breakpoints and other breakpoints were 57.21% and 14.90% for AMX (p<0.001), 38.94% and 38.94% for CLA (p = 1), 39.42% and 50.96% for MTZ (p<0.001), 12.98% and 10.58% for TET (p = 0.025), 35.10% and 35.10% for LEV (p = 1), respectively. Conclusions Our results demonstrate that AMX, FZD, and TET, but not MTZ, CLR or LEV, showed good anti-H. pylori activity in vitro in South China. When different breakpoints were used, similar results were found with CLA, and LEV, but not with AMX, MTZ, or TET.

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Antimicrobial susceptibility of Pasteurella multocida and Haemophilus parasuis isolates associated with porcine pneumonia

Acta Veterinaria Brno ◽

10.2754/avb201382010003 ◽

2013 ◽

Vol 82 (1) ◽

pp. 3-7 ◽

Cited By ~ 18

Author(s):

Kateřina Nedbalcová ◽

Zdeňka Kučerová

Keyword(s):

Czech Republic ◽

Pasteurella Multocida ◽

Antimicrobial Agents ◽

Haemophilus Parasuis ◽

The Czech Republic ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Amoxicillin Clavulanic Acid ◽

High Level ◽

Resistance Rates

Pasteurella multocidaandHaemophilus parasuispig isolates obtained in the Czech Republic were tested for their susceptibility against selected antimicrobial agents by broth microdilution method between 2008 and 2011. A low degree of resistance was observed for ampicillin, amoxicillin/clavulanic acid, ceftiofur, tulathromycin, tilmicosin, florfenicol and enrofloxacin in 20 (6.0%), 15 (4.5 %), 2 (0.6%), 8 (2.4%), 13 (3.9%), 5 (1.5%) and 5 (1.5%)P. multocidaisolates as well as for tiamulin, gentamicin, tulathromycin, tilmicosin and ampicillin in 2 (2.4%), 2 (2.4%), 3 (3.6%), 3 (3.6%) and 6 (7.2%)H. parasuisisolates. In addition, moderate level of resistance to tiamulin was found in 60 (18.1%)P. multocidaisolates and high level of resistance for tetracycline was detected in 107 (32.2 %)P. multocidaisolates and in 23 (27.7 %)H. parasuisisolates. Differences between resistance rates ofP. multocidaandH. parasuiswere significant (P≤ 0.5) only for tiamulin. These data confirmed that antimicrobial resistance is not very widespread among current porcineP. multocidaandH. parasuisisolates in the Czech Republic.

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Prevalence of Antimicrobial Resistance among Clinical Isolates of Bacteroides fragilis Group in Canada in 2010-2011: CANWARD Surveillance Study

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.05823-11 ◽

2011 ◽

Vol 56 (3) ◽

pp. 1247-1252 ◽

Cited By ~ 58

Author(s):

James A. Karlowsky ◽

Andrew J. Walkty ◽

Heather J. Adam ◽

Melanie R. Baxter ◽

Daryl J. Hoban ◽

...

Keyword(s):

Antimicrobial Agents ◽

Bacteroides Fragilis ◽

Clinical Isolates ◽

Surveillance Study ◽

Content Type ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Amoxicillin Clavulanate ◽

Bacteroides Fragilis Group ◽

Bacteroides Ovatus

ABSTRACTClinical isolates of theBacteroides fragilisgroup (n= 387) were collected from patients attending nine Canadian hospitals in 2010-2011 and tested for susceptibility to 10 antimicrobial agents using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method.B. fragilis(59.9%),Bacteroides ovatus(16.3%), andBacteroides thetaiotaomicron(12.7%) accounted for ∼90% of isolates collected. Overall rates of percent susceptibility were as follows: 99.7%, metronidazole; 99.5%, piperacillin-tazobactam; 99.2%, imipenem; 97.7%, ertapenem; 92.0%, doripenem; 87.3%, amoxicillin-clavulanate; 80.9%, tigecycline; 65.9%, cefoxitin; 55.6%, moxifloxacin; and 52.2%, clindamycin. Percent susceptibility to cefoxitin, clindamycin, and moxifloxacin was lowest forB. thetaiotaomicron(n= 49, 24.5%),Parabacteroides distasonis/P. merdae(n= 11, 9.1%), andB. ovatus(n= 63, 31.8%), respectively. One isolate (B. thetaiotaomicron) was resistant to metronidazole, and two isolates (bothB. fragilis) were resistant to both piperacillin-tazobactam and imipenem. Since the last published surveillance study describing Canadian isolates ofB. fragilisgroup almost 20 years ago (A.-M. Bourgault et al., Antimicrob. Agents Chemother. 36:343–347, 1992), rates of resistance have increased for amoxicillin-clavulanate, from 0.8% (1992) to 6.2% (2010-2011), and for clindamycin, from 9% (1992) to 34.1% (2010-2011).

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In vitro activity of antimicrobial agents with and without sulbactam, EDTA and sulbactam-EDTA on ESBLs-producing Escherichia coli isolated from healthy Tibetan yaks

10.21203/rs.3.rs-39215/v1 ◽

2020 ◽

Author(s):

Baoguang Liu ◽

Xiaoling Yuan ◽

Yiheng Chen ◽

Xiaoshen Li ◽

Ming Bai ◽

...

Keyword(s):

Escherichia Coli ◽

Nasal Swab ◽

Antimicrobial Agents ◽

Synergistic Effects ◽

E Coli ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Third Generation Cephalosporins ◽

Enhance Activity

Abstract Background The spread of ESBLs-producing bacteria has been strikingly rapid in many regions of the world and it causes therapeutic difficulties in everyday practice. The aims of this study were to investigate the prevalence and susceptibilities of ESBLs-producing Escherichia coli isolates from healthy Tibetan yaks in China, to evaluate the activity of drug combinations on ESBLs-producing E. coli isolates. Methods From July 2018 to August 2019, a total of 750 nasal swab samples were tested for the presence of E. coli and ESBLs-producing strains. The MICs of 11 antimicrobial agents alone and combinations with sulbactam, EDTA or sulbactam-EDTA against 240 ESBLs-producing E.coli strains were determined by the broth microdilution method. Results Overall, 59.87% (n = 449) of the samples were positive for E. coli, 240 (53.45%) of 449 E. coli isolates were confirmed to be ESBLs-producing. The addition of sulbactam to the third generation cephalosporins, amikacin and fosfomycin for all isolates resulted in low MICs, increasing the level of susceptibility from 0, 0 and 0% to 50 ~ 87.5, 4.2 and 100% respectively. The addition of EDTA to fluoroquinolones, doxycycline, florfenicol, amikacin and fosfomycin, showed improved activities and resulted in low MICs, increasing the level of susceptibility from 0, 0, 8.3, 0 and 0% to 4.2 ~ 29.2, 33.3, 33.3, 66.7 and 45.8%, respectively. All other antibacterials (except fluoroquinolones, doxycycline and florfenicol), when combined with sulbactam-EDTA, were found to be more active than combinations only with sulbactam or with EDTA against most of isolates, with lower MIC50s and MIC90s. Conclusion In conclusion, ESBLs-producing E. coli isolates were widespread in healthy Tibetan yaks in China. ESBLs-producing E. coli isolates exhibited varying degrees of multidrug resistance. This study these findings suggested that sulbactam can enhance activity of β-lactams and some non-β-lactams of antimicrobial agents and had a synergistic effects with EDTA in improving activities of some families of antimicrobials.

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Antimicrobial Resistance in Campylobacter jejuni from Broilers and Broiler House Environments in Norway

Journal of Food Protection ◽

10.4315/0362-028x-70.3.736 ◽

2007 ◽

Vol 70 (3) ◽

pp. 736-738 ◽

Cited By ~ 16

Author(s):

M. NORSTRÖM ◽

G. JOHNSEN ◽

M. HOFSHAGEN ◽

H. THARALDSEN ◽

H. KRUSE

Keyword(s):

Antimicrobial Resistance ◽

Campylobacter Jejuni ◽

Antimicrobial Susceptibility ◽

Antimicrobial Agents ◽

Monitoring Program ◽

Outdoor Environment ◽

Susceptibility Data ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Broiler House

Antimicrobial susceptibility in Campylobacter jejuni collected from the environment outside four broiler houses (n = 63) and from the environment inside these broiler houses (including broiler droppings) (n = 36) from May to September 2004 was studied and compared with isolates from Norwegian broilers analyzed within the frame of the Norwegian monitoring program of antimicrobial resistance in feed, food, and animals (NORM-VET) in 2004 (n = 75). The MICs of oxytetracycline, ampicillin, erythromycin, gentamicin, enrofloxacin, and nalidixic acid were obtained by the broth microdilution method VetMIC. The present study, which to our knowledge is the first Norwegian study on the occurrence of antimicrobial resistance in Campylobacter spp. from the environment of broiler houses, revealed a very low occurrence of antimicrobial resistance in C. jejuni from the broilers and broiler house environments studied. All isolates originating from the four broiler houses studied were susceptible to all the antimicrobial agents tested, except for one isolate from the outdoor environment (courtyard soil), which was resistant to oxytetracycline (MIC, 8 mg/liter). For the isolates from broilers (NORM-VET), low prevalences of resistance to oxytetracycline (1.3%) and ampicillin (4%) were observed. No quinolone resistance was observed. The results for the broiler isolates are in agreement with the earlier findings of a very low prevalence of resistance in Campylobacter from broilers in Norway, which reflects the low usage of antimicrobials in Norwegian broiler production. Furthermore, the present data are in accordance with antimicrobial susceptibility data for C. jejuni from domestically acquired human cases.

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Susceptibility trends of ceftolozane/tazobactam and comparators when tested against European Gram-negative bacterial surveillance isolates collected during 2012–18

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkaa278 ◽

2020 ◽

Vol 75 (10) ◽

pp. 2907-2913 ◽

Cited By ~ 1

Author(s):

Helio S Sader ◽

Cecilia G Carvalhaes ◽

Leonard R Duncan ◽

Robert K Flamm ◽

Dee Shortridge

Keyword(s):

Eastern Europe ◽

Active Compound ◽

Western Europe ◽

Antimicrobial Agents ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Microdilution Method ◽

Broth Microdilution Method ◽

Systemic Infections

Abstract Background The Program to Assess Ceftolozane/Tazobactam Susceptibility (PACTS) monitors the in vitro activity of ceftolozane/tazobactam and numerous antimicrobial agents against Gram-negative bacteria worldwide. Objectives To evaluate the activity of ceftolozane/tazobactam and resistance trends among Pseudomonas aeruginosa and Enterobacterales isolates in Europe between 2012 and 2018. Methods P. aeruginosa (7503) and Enterobacterales (30 582) isolates were collected from 53 medical centres in 26 countries in Europe and the Mediterranean region and tested for susceptibility by reference broth microdilution method in a central laboratory. MIC results were interpreted using EUCAST criteria. Results Ceftolozane/tazobactam was the most active compound tested against P. aeruginosa isolates after colistin, with overall susceptibility rates of 94.1% in Western Europe and 80.9% in Eastern Europe. Moreover, ceftolozane/tazobactam retained activity against 75.2% and 59.2% of meropenem-non-susceptible P. aeruginosa isolates in Western and Eastern Europe, respectively. Tobramycin was the third most active compound tested against P. aeruginosa, with susceptibility rates of 88.6% and 70.9% in Western and Eastern Europe, respectively. Ceftolozane/tazobactam was active against 94.5% of all Enterobacterales and 96.1% of meropenem-susceptible isolates from Western Europe. In Eastern Europe, ceftolozane/tazobactam was active against 79.4% of Enterobacterales overall and 86.2% of meropenem-susceptible isolates. Discussion Antimicrobial susceptibility rates for agents commonly used to treat serious systemic infections varied widely among nations and geographic regions and were generally lower in Eastern Europe compared with Western Europe. Ceftolozane/tazobactam demonstrated potent activity against P. aeruginosa, including MDR strains, and retained activity against most meropenem-susceptible Enterobacterales causing infection in European medical centres.

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Antimicrobial susceptibility of Pasteurella multocida isolated from sheep and pigs in Spain – Short communication

Acta Veterinaria Hungarica ◽

10.1556/004.2019.048 ◽

2019 ◽

Vol 67 (4) ◽

pp. 489-498

Author(s):

Dolores Cid ◽

José Francisco Fernández-Garayzábal ◽

Chris Pinto ◽

Lucas Domínguez ◽

Ana Isabel Vela

Keyword(s):

High Resistance ◽

Antimicrobial Susceptibility ◽

Pasteurella Multocida ◽

Antimicrobial Agents ◽

Empirical Therapy ◽

Microdilution Method ◽

Low Levels ◽

Resistance Rates ◽

Farming Industry ◽

Susceptibility Patterns

Pasteurella multocida is responsible for economically important diseases in sheep and pigs. Antimicrobial susceptibility studies are essential for initiating rational and effective empirical therapy of P. multocida infections. In this study we investigated the antimicrobial susceptibility to 18 antimicrobial agents of 156 clinical isolates of P. multocida from sheep (n = 87) and pigs (n = 69) using the microdilution method. Both sheep and pig isolates exhibited low levels of resistance (≤ 15%) to ceftiofur, gentamicin, neomycin, spectinomycin, chlortetracycline, tulathromycin, florfenicol, danofloxacin, and enrofloxacin and trimethoprim/sulphamethoxazole, high resistance rates (> 15% up to 50%) to oxytetracycline, tilmicosin, and tiamulin, and very high resistance rates (> 50%) to tylosin tartrate, clindamycin, and sulphadimethoxine. However, sheep isolates exhibited significantly lower percentages of resistance and lower MIC90 values (P < 0.05) than pig isolates for most of the antimicrobials tested. In addition, sheep isolates exhibited also significantly lower phenotypic antimicrobial resistance diversity (8 resistotypes vs. 30 resistotypes). LAC-LIN-SUL-MAC was the resistotype most frequently detected in sheep (39.1%) and LIN-SUL-MAC in pig isolates (26.1%). The differences in susceptibility patterns could be influenced by the lower use of antimicrobials in the small ruminant industry compared with the pig farming industry.

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In Vitro Activity of Eravacycline against Gram-Positive Bacteria Isolated in Clinical Laboratories Worldwide from 2013 to 2017

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01715-19 ◽

2019 ◽

Vol 64 (3) ◽

Cited By ~ 1

Author(s):

Ian Morrissey ◽

Stephen Hawser ◽

Sibylle H. Lob ◽

James A. Karlowsky ◽

Matteo Bassetti ◽

...

Keyword(s):

Antimicrobial Agents ◽

Clinical Isolates ◽

Gram Positive ◽

Content Type ◽

Gram Positive Bacteria ◽

Microdilution Method ◽

Clinical Laboratories ◽

Broth Microdilution Method ◽

Doubling Dilution

ABSTRACT Eravacycline is a novel, fully synthetic fluorocycline antibiotic being developed for the treatment of serious infections, including those caused by resistant Gram-positive pathogens. Here, we evaluated the in vitro activities of eravacycline and comparator antimicrobial agents against a recent global collection of frequently encountered clinical isolates of Gram-positive bacteria. The CLSI broth microdilution method was used to determine in vitro MIC data for isolates of Enterococcus spp. (n = 2,807), Staphylococcus spp. (n = 4,331), and Streptococcus spp. (n = 3,373) isolated primarily from respiratory, intra-abdominal, urinary, and skin specimens by clinical laboratories in 37 countries on three continents from 2013 to 2017. Susceptibilities were interpreted using both CLSI and EUCAST breakpoints. There were no substantive differences (a >1-doubling-dilution increase or decrease) in eravacycline MIC90 values for different species/organism groups over time or by region. Eravacycline showed MIC50 and MIC90 results of 0.06 and 0.12 μg/ml, respectively, when tested against Staphylococcus aureus, regardless of methicillin susceptibility. The MIC90 values of eravacycline for Staphylococcus epidermidis and Staphylococcus haemolyticus were equal (0.5 μg/ml). The eravacycline MIC90s for Enterococcus faecalis and Enterococcus faecium were 0.06 μg/ml and were within 1 doubling dilution regardless of the vancomycin susceptibility profile. Eravacycline exhibited MIC90 results of ≤0.06 μg/ml when tested against Streptococcus pneumoniae and beta-hemolytic and viridans group streptococcal isolates. In this surveillance study, eravacycline demonstrated potent in vitro activity against frequently isolated clinical isolates of Gram-positive bacteria (Enterococcus, Staphylococcus, and Streptococcus spp.), including isolates collected over a 5-year period (2013 to 2017), underscoring its potential benefit in the treatment of infections caused by common Gram-positive pathogens.

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Generation Times of E. coli Prolong with Increasing Tannin Concentration while the Lag Phase Extends Exponentially

Plants ◽

10.3390/plants9121680 ◽

2020 ◽

Vol 9 (12) ◽

pp. 1680

Author(s):

Sara Štumpf ◽

Gregor Hostnik ◽

Mateja Primožič ◽

Maja Leitgeb ◽

Urban Bren

Keyword(s):

Antimicrobial Agents ◽

Direct Consequence ◽

Lag Phase ◽

Exponential Relationship ◽

Phase Duration ◽

E Coli ◽

Microdilution Method ◽

Generation Times ◽

Broth Microdilution Method ◽

Tannin Concentration

The current study examines the effect of tannins and tannin extracts on the lag phase duration, growth rate, and generation time of Escherichia coli. Effects of castalagin, vescalagin, gallic acid, Colistizer, tannic acid as well as chestnut, mimosa, and quebracho extracts were determined on E. coli’s growth phases using the broth microdilution method and obtained by turbidimetric measurements. E. coli responds to the stress caused by the investigated antimicrobial agents with reduced growth rates, longer generation times, and extended lag phases. Prolongation of the lag phase was relatively small at low tannin concentrations, while it became more pronounced at concentrations above half the MIC. Moreover, for the first time, it was observed that lag time extensions follow a strict exponential relationship with increasing tannin concentrations. This feature is very likely a direct consequence of the tannin complexation of certain essential ions from the growth medium, making them unavailable to E. coli for its growth.

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Incidence of Antibiotic Resistant Escherichia Coli in Iraqi Milk Products

Journal of Food Protection ◽

10.4315/0362-028x-53.10.846 ◽

1990 ◽

Vol 53 (10) ◽

pp. 846-848

Author(s):

F. M. ABBAR ◽

H. KH. KADDER

Keyword(s):

Escherichia Coli ◽

Antimicrobial Agents ◽

Resistance Pattern ◽

Antibiotic Resistant ◽

Milk Products ◽

E Coli ◽

Antimicrobial Sensitivity ◽

Significant Difference ◽

Resistance To Penicillin ◽

Overall Resistance

The antimicrobial sensitivity of 430 Escherichia coli strains isolated from three types of locally processed Iraqi milk products was determined. Four hundred and one (93.2%) isolates were resistant to one or more antimicrobial agents, and only 29 (6.7%) isolates were sensitive to all 12 agents tested. The incidence of resistant E. coli was 95.5%, 90.4% and 84.4% in isolates from cheese, kishfa, and gaymer, respectively. There was no significant difference in resistance among E. coli strains from various milk products. Overall, resistance to penicillin (92.3%), erythromycin (75.8%), cephaloridine (71.9%), ampicillin (57.7%), and tetracycline (37%) was most frequent, whereas isolates were least resistant to kanamycin (7.2%), chloramphenicol (8.1%), nalidixic acid (8.6%), gentamycin (9%), streptomycin (12.5%), trimethoprim (14%), and colistin (18%). The predominant antimicrobial resistance pattern was penicillin, ampicillin, cephaloridine, and erythromycin detected in 77 (18%). The high resistance of E. coli strains isolated from product samples was suggestive of misuse of these drugs in Iraq.

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