Antimicrobial Susceptibility of Multidrug-Resistant <i>Acinetobacter baumanii</i>in a Teaching Hospital: A Two-Year Observation

Multidrug-resistant (MDR) Acinetobacter baumanii (A. baumanii) caused hospital acquired infection, typically in critical-ill patients with medical devices. This is a retrospective descriptive study on epidemiology and microbiology data to determine the antimicrobial susceptibility pattern of MDR-Acinetobacter baumanii isolates from a teaching hospital in Tangerang, Indonesia from Januari 2013 to December 2014. A total of 84 A. baumanii were collected. Patients suffering from respiratory tract infection had the highest number (41.7%) of A. baumanii isolate. There were 39 (46.6%) patients admitted in critical care. A. baumanii isolates in this study mostly were multidrug-resistant organisms with low susceptibility level to 11 antibiotic tested, 44% - 69% in 2013 and 26% - 67% in 2014. A high susceptibility level was observed to amikacin (80% and 79% in 2013, 2014 consecutively) and trimethoprim-sulfamethoxazole (73% and 72% in 2013, 2014 consecutively). A. baumanii is a hospital acquired pathogen in critically-ill patients. The susceptibility pattern of this study result showed MDR organism. There was a sharp decrease of susceptibility in all antibiotics studied from 2013 to 2014 except amikacin and trimethoprim-sulfamethoxazole.

Importance of antimicrobial susceptibility testing for the management of eradication in Helicobacter pylori infection

The management of Helicobacter pylori(H. pylori) infection treatment differs from the common treatment protocol for other infectious diseases. Because culture-or molecular-guided approaches face several practical issues, such as the invasive procedures required to obtain gastric biopsy specimens and the lack of availability of routine laboratory testing in some places, H. pylori treatment includes the administration of two or three empirically selected antibiotics combined with a proton pump inhibitor rather than evidence-based eradication treatment. The efficacy of empirical therapy is decreasing, mostly due to increasing multiple resistance. Multiresistance to levofloxacin, clarithromycin, and metronidazole, which are commonly used in empirical treatments, appears to have increased in many countries. Mutations play a primary role in the antimicrobial resistance of H. pylori, but many different mechanisms can be involved in the development of antibiotic resistance. Determining and understanding these possible mechanisms might allow the development of new methods for the detection of H. pylori and the determination of antimicrobial resistance. A treatment based on the detection of antimicrobial resistance is usually more effective than empirical treatment. Nevertheless, such an approach before treatment is still not recommended in the Maastricht guidelines due to the difficulty associated with the routine application of available cultureor molecular-based susceptibility tests, which are usually administered in cases of treatment failure. The management of first and rescue treatments requires further research due to the steadily increase in antimicrobial resistance.

Threefold Increase in the Number of Drug Resistant TB Cases after Introduction of Universal Drug Susceptibility Testing: Experiences from Two South India Districts

Background: In India, tuberculosis (TB) is a major public health problem, and the advent of drug resistance TB (DR-TB) has worsened the situation. The Revised National TB Control Programme (RNTCP) has introduced universal drug susceptibility testing (UDST) for all diagnosed TB cases in 2018. We conducted this study to know the advantage of implementing UDST when compared to selective testing existent in 2017 on key diagnostic cascade parameters and to identify the challenges in the implementation of UDST. Methods: The study was conducted in two districts of Karnataka, India during January 2017-December 2018. The quantitative part consisted of before-and-after design and the qualitative part consisted of descriptive design. Results: In 2017 (during selective testing/“before” period) out of the 2440 TB patients, 80 (3%) were diagnosed with Isoniazid and Rifampicin resistance patients;in contrast in 2018 (during UDST/“after” period) of the 5129 TB patients 258 (5%) were diagnosed with Isoniazid and Rifampicin resistance. However, the proportion of eligible patients tested for rifampicin resistance during the “after” period was 60% when compared to 100% during the “before” period and median turnaround time for testing was also longer during the “after” period when compared to the “before” period (32.5 days vs 27.5 days). Major reasons for these two gaps were found to be difficulties in collecting sputum specimens and transportation. Conclusion: The rollout of UDST has led to a three-fold increase in a number of DR-TB cases detected in the region. There is a need for the programme to increase the proportion tested for DST by increasing the laboratory capacity and address the challenges in sputum collection and transportation.

Susceptibility of Mixed Infection of Ureaplasma Urealyticum and Mycoplasma Hominis to Seven Antimicrobial Agents and Comparison with that of Ureaplasma Urealyticum Infection

In order to investigate the susceptibility of mixed infection of Ureaplasma Urealyticum (UU) and Mycoplasma Hominis (MH) to 7 kinds of antimicrobial agents and comparison with that of UU infection in NGU patients, the in vitro susceptibility was determined by using microdilution method. The positive results were analyzed. The results showed that the sequence of susceptibility to 7 kinds of antimicrobial agents for both UU infection group and UU-MH mixed infection group was almost the same from the highest susceptibility to the lowest accordingly: Josamycin, Doxycycline, Minocycline, Sparfloxacin, Roxithromycin, Ofloxacin and Azithromycin. The total drug resistance rate for UU-MH mixed infection group (97. 67 %) was significantly higher than that for UU infection group (44. 67 %, P<.0. 01). The highest drug resistance rate in UU group and UU-MH mixed infection group was 31. 33 % (Ofloxacin) and 90. 48 % (Azithromycin) respectively. UU-MH mixed infection showed an increased drug resistance and changes of drug resistance spectrum.

Antimicrobial susceptibility patterns of Streptococcus pneumoniae over 6 years at Gondar University Hospital, Northwest Ethiopia

Objective:To assess the magnitude and antimicrobial susceptibility patterns ofStreptococcus pneumoniaeisolates from various clinical specimens.Methods:A record based on retrospectivestudy was conducted at Gondar University Teaching Hospital from September 2007 to January 2012.All patients who visited Gondar University Hospital and provided clinical specimens(body fluids,discharge,swab and blood)for routine bacteriological culturing and antimicrobial susceptibilitytesting were taken for analysis.Clinical specimens were processed for bacterial culture accordingto the standard procedures.Antimicrobial susceptibility test for isolated organisms was doneusing agar disk diffusion method.The data were entered and analyzed using SPSS software version16 package.Results:One hundred and fifty threeStreptococcus pneumoniaewere isolated frompatients who visited Gondar University Teaching Hospital bacteriology laboratory for culture.Majority of the pneumococcal isolates were from inpatients[111(72.5%)],and 74(48.4%)were frombody fluids.Out of the total isolates,93(61%)were found to be resistant to at least one antibioticused for susceptibility testing.Forty eight(43.2%)of the isolates were multi-drug resistant(resistantto two or more drugs).The resistance rate noted for both ciprofloxacin 17(11.1%)and ceftriaxone15(9.8%)were alarming.Conclusions:High proportions of the isolates tend to be increasinglyresistant to the commonly prescribed drugs.The recommended drug of choice like ciprofloxacinand ceftriaxone were found to be less susceptible in the study area.Based on the findings,wetherefore recommend that antimicrobial agents should be inspected for acceptable activity beforethey are prescribed and administered empirically.Further study with a better design and surveyof antimicrobial susceptibility at large scale shoule be performed to draw advanced information.

Prevalence and antimicrobial susceptibility patterns of bacteria in ICU patients with lower respiratory tract infection: A cross-sectional study

Objective: To investigate the prevalence of isolated organisms in patients with lower respiratory tract infections and the antibiotic susceptibilities at a tertiary care center. Methods: In this observational and cross-sectional analysis, 114 patients admitted in the intensive care unit were enrolled. The endotracheal aspirates and bronchoalveolar lavage were collected. The bacteria were isolated and identified, and finally, antimicrobial sensitive pattern of the isolated bacteria was examined. Results: The prevalence of infection was 72.72% in male patients and 27.28% in females. The predominant bacteria were Klebsiella pneumoniae (37.50%) followed by Acinetobacter spp. (36.36%), Pseudomonas aeruginosa (7.95%),Escherichia coli (6.81%), Proteus mirabilis (2.27%), atypical Escherichia coli (1.13%), Enterococcus spp. (1.13%),Elizabethkingia meningoseptica (1.13%),Staphylococcus aureus (1.13%),Proteus vulgaris (1.13%), Citrobacter freundii (1.13%), and Citrobacter koseri (1.13%). High resistance to cephalosporins (82.18%) was demonstrated in all Gram-negative bacteria. Bacteria showed susceptibility to colistin (88.75%) followed by tigecycline (83.11%), gentamycin (36.18%), and amikacin (49.23%). Conclusions: As the most frequent respiratory organisms, Klebsiella pneumoniae and Acinetobacter spp. have increased resistance to cephalosporins and susceptibility to colistin followed by tigecycline.

External Bacterial Flora and Antimicrobial Susceptibility Patterns of Staphylococcus spp. and Pseudomonas spp. Isolated from Two Household Cockroaches, Blattella germanica and Blatta orientalis

A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches （Blattella germanica and Blatta orientalis） collected from households in Tebessa （northeast AIgeria）.Three major bacterial groups were cultured （total aerobic, enterobacteria, and staphylococci） from 14 specimens of cockroaches, and antibiotic susceptibility was tested for both Staphylococcus and Pseudomonas isolates. Culturing showed that the total bacterial load of cockroaches from different households were comparable （P〈0.001） and enterobacteria were the predominant colonizers of the insect surface, with a bacterial load of （2.1×10^5 CFU/insect）, whereas the staphylococci group was the minority. Twenty-eight bacterial species were isolated, and susceptibility patterns showed that most of the staphylococci isolates were highly susceptible to chloramphenicol, gentamycin, pristinamycin, ofloxacin, clindamycin, and vancomycin; however, Pseudomonas strains exhibited resistance to amoxicillin/clavulanic acid, imipenem, and the second-generation antibiotic cephalosporin cefuroxime.

Streptococcus agalactiae:Identification methods,antimicrobial susceptibility, and resistance genes in pregnant women

BACKGROUND Group B Streptococcus(GBS)is a normal component of the gastrointestinal and genital microbiota in humans and can lead to important infections in newborns.AIM To compare GBS isolation and identification methods as well as to assess the antibiotic susceptibility and to identify resistance genes in GBS strains from pregnant women attended in healthcare services from the city of Vitória da Conquista,in Bahia State,Brazil.METHODS From January 2017 to February 2018,vaginorectal swabs were obtained from 186 participants and the samples were seeded onto chromogenic agar for GBS before and after inoculation in selective broth.Confirmatory identification using 3 CAMP and latex tests was performed in samples with GBS-suggestive colonies.Then,disk diffusion antibiograms were performed in GBS-positive samples,and the detection of the resistance genes ermB,ermTR,mefA,and linB in the clindamycin and/or erythromycin-resistant samples was carried out.RESULTS Thirty-two samples(17.2%)were GBS-positive.The culture in chromogenic agar after sample incubation in selective broth was the most sensitive method(96.9%)for GBS detection.All isolates were susceptible to penicillin,ampicillin,cefotaxime,and vancomycin.Clindamycin resistance was observed in 6 samples(18.8%),while 8 samples(25%)were erythromycin-resistant.All erythromycin and/or clindamycin-resistant GBS strains had negative D-tests.Two strains(25%)presented an M phenotype and 6 isolates(75%)presented a cMLSB phenotype.The ermB gene was identified in 4 samples(44.4%),the mefA gene was also found in 4 samples(44.4%),the ermTR gene was identified in 1 isolate(11.1%),and the linB gene was not found in any isolate.CONCLUSION This study evidenced that the screening for SGB can be performed by means of various methods,including chromogenic media,and that the chemoprophylaxis for pregnant women who cannot use penicillin must be susceptibility-guided.

Genetic Characteristics and Antimicrobial Susceptibility of Arcobacter butzleri Isolates from Raw Chicken Meat and Patients with Diarrhea in China

Arcobacter is an emerging foodborne pathogen worldwide.In this study,the prevalence,antimicrobial susceptibility and genetic characteristics of Arcobacter from different sources were investigated.Eighteen A.butzleri isolates were obtained from 60 raw chicken meat samples(16/60,27%)and 150 patients with diarrhea(2/150,1.3%).The resistance ratios to nalidixic acid,ciprofloxacin,clindamycin,chloramphenicol,and florfenicol were 83.33%(15/18),38.89%(7/18),38.89%(7/18),33.33%(6/18)and 33.33%(6/18),respectively.We performed whole genome sequencing of the 18 isolates,and we predicted antibiotic resistance genes and virulence factors by using assembled genomes through blastx analysis.Two resistance genes,blaOXA-464 and tet(H),and the C254T mutation in gyrA,were identified in the genomes of some resistant isolates.Furthermore,virulence genes,such as flgG,flhA,flhB,fliI,fliP,motA,cadF,cjl349,ciaB,mviN,pldA and tlyA,were found in all strains,whereas hecA,hecB and iroE were found in only some strains.Phylogenetic tree analysis of A.butzleri isolates on the basis of the core-genome single nucleotide polymorphisms showed that two isolates from patients with diarrhea clustered together,separately from the isolates from raw chicken and the chicken strains.This study is the first comprehensive analysis of Arcobacter isolated in Beijing.

Expert Consensus on Polymyxin Antimicrobial Susceptibility Testing and Clinical Interpretation

The polymyxins are important antimicrobial agents against antibiotic-resistant gram-negative bacilli.In 2020,the Clinical and Laboratory Standards Institute modified the clinical breakpoints for polymyxin susceptibility test by eliminating the"susceptible"interpretive category,only reporting intermediate(≤2 mg/L)and resistant(≥4 mg/L).However,the European Committee on Antimicrobial Susceptibility Testing recommended the use of clinical breakpoints of W2 mg/L as susceptible and>2 mg/L as resistant.The first-line laboratorians and clinicians in China have been perplexed by the inconsistence of international polymyxin clinical breakpoints and discouraged by the difficulty of conducting polymyxin susceptibility testing.Therefore,it is urgently needed to make it clear for the laboratorians in China to know how to accurately carry out polymyxin susceptibility testing and standardize the interpretation of susceptibility testing results.To this end,the experts from relevant fields were convened to formulate this consensus statement on the testing and clinical interpretation of polymyxin susceptibility.Relevant recommendations are proposed accordingly for laboratorians and clinicians to streamline their daily work.

Drug Susceptibility Test of Volatile Oil of Artemisiaargyi to Avian Pathogenic Escherichia coli

The volatile oil of Artemisia argyi was extracted by ultrasonic assisted extraction, and the extraction rate of volatile oil was 0.68%. Thevolatile oil of A. argyi was emulsified with 1% Tween-80, and drug susceptibility test was conducted with avian Escherichia coli. The results showedthat the volatile oil of A. argyi had antibacterial effect against avian E. coli, and the minimal inhibitory concentration was 50 mg/mL. Taking sixcommon antibiotics as the control, drug susceptibility test was conducted with volatile oil of A. argyi. The results showed that 10 strains of E. coliwere sensitive to the volatile oil of A. argyi, three of which had different degrees of resistance and one had the tendency of resistance.

Antimicrobial Susceptibility Patterns of Staphylococcus aureus Strains Isolated at the Namibia Institute of Pathology from 2012 to 2014

Staphylococcus aureus (S. aureus) is known to acquire resistance to new drugs and continues to defy at-tempts to control it. Infections caused by antibiotic resistant strains of S. aureus have reached epidemic proportions globally and the increasing rates of antimicrobial resistance are resulting in fewer treatment options. Methicillin resistant S. aureus (MRSA) has also emerged as a serious therapeutic problem worldwide. However, data on the antimicrobial susceptibility patterns of this bacterium over a period of time in Namibia are not available. A descriptive retrospective study was therefore conducted to investigate the antimicrobial susceptibility patterns of 600 Staphylococcus aureus strains isolated at the Namibia Institute of Pathology (NIP) from January 2012 to December 2014. The results showed that a high proportion of isolates were resistant to penicillin (92.4%) and cotrimoxazole (44.9%), while the antibiotics to which the isolates were least resistant included vancomycin (0%), fusidic acid (0.3%) and ciprofloxacin (4.4%). Methicillin resistance was observed in 13.5% of the staphylococcal isolates. Apart from clindamycin (P value = 0.039) and cotrimoxazole (P value = 0.030), the susceptibility patterns of the antibiotics did not differ significantly over the three years. Moreover, wound swabs and sputum were the clinical samples from which S. aureus was most commonly isolated at NIP. The results from this study suggest that continuous local surveillance on the resistance patterns of S. aureus should be performed on regular basis in Namibia, in order to have adequate information for the empirical treatment of S. aureus infections.

Antimicrobial susceptibility profile of community acquired and nosocomial isolates of Escherichia coli from clinical blood culture specimens at a Nigerian university teaching hospital

Objective:To ascertain the antibiotic susceptibility patterns of Escherichia coli recovered from blood culture specimens in Calabar.Nigeria.Methods:The study was retrospective in nature and was carried out at University of Calabar Teaching Hospital(UCTH) Calabar.Data generated from blood culture specimens over a five year period(Feb.2004-Feb.2009) was compiled, relevant information such as age,sex,organism recovered and antibiotic susceptibility patterns were obtained from patients records.Samples were collected,transported,stored and processed using standard laboratory procedures.Data obtained was analysed using Epi Info 6 statistical software.Results:Escherichia coli was responsible for 15.3%(31/203) of the blood infections being the third most common microorganism encountered.The community acquired(CA) isolates of the organism were significantly less resistant(P【0.05),compared to the nosocomial(NC) isolates against ampicillin.cloxacillin,amoxicillin,tetracycline,co-trimoxazole.chloramphenicol and erythromycin.The sensitivity of both the NC and CA isolates of Escherichia coli to amikacin, augmentin,ofloxacin,ciprofloxacin,ceftazidime,cefuroxime,ceftriaxone and rifampicin was generally high(80-100%) with no significant difference(P】0.05).Majority(】95.0%) of the NC isolates of Escherichia coli were resistant to six of the antibiotics tested.Conclusions:Control mechanisms for hospital acquired infections should be stepped up so as lo limit the spread of the highly resistant bacterial strains.Also the sale and consumption of antibiotics by the public need to be regulated.

Comparative drug susceptibility study of five clonal strains of Trichomonas vaginalis in vitro

Objective:To produce comparative data on a group of Trichomonas vaginalis clonal strains with varied drug responses using identical methods and materials.Methods:Five clonal strains of Trichomonas vaginalis were isolated from reference strain using agar plate technique.The variability of growth kinetic and susceptibility of clonal strain to metronidazole,tinidazole, satranidazole and nitazoxanide were observed in 96 well microlilre plate.Results:Among these clonal strains there was a good correlation between rates of growth with the relative susceptibility of the strains to drugs in vitro.Regarding metronidazole,tinidazole and satranidazole susceptibility,different degrees of susceptibility were determined.However,no difference in nitazoxanide susceptibility was found between the clonal strain tested and a reference strain. Conclusions:This is the first description of biological variability in clonal stock of Trichomonas vaginalis.Different degrees of drug susceptibility were determined among clonal strains tested. Further studies will be necessary to ascertain the importance of this variability in clinical infection.

Change in molecular weight due to important pfatp6 and pfmdr1 polymorphisms and susceptibility to antimalarial drug:Possible role of epigenetic phenomenon

Malaria is an important tropical mosquito borne infection. It is still the present global public health issue. The management of malaria requires antimalarial drugs. The resistance to antimalarial drugs is a very big problem. The genetic variant is proposed to be an important factor affecting susceptibility to antimalarial drug. Here, the authors studied the change in molecular weight due to important pfatp6 and pfmdr1 polymorphisms and further implied the interrelationship with susceptibility to antimalarial drug. The greatest change can be seen in case of G639D(of pfatp6 polymorphism) while the least change can be seen in the case of N1042D(of pfmdr1 polymorphism). The results from some studies imply that there must be other factors that affect the susceptibility to antimalarial drugs. Those factors might be protein conformation factors, epigenetic factors or environmental factors. Further studies on these aspects should be carried out. It is concluded for possible role of epigenetic phenomenon.

Genomic characterization and antimicrobial susceptibility of bovine intrauterine Escherichia coli and its relationship with postpartum uterine infections

To investigate the roles of Escherichia coli in the pathogenesis of postpartum uterine diseases in dairy cows, a total of 145 E. coli isolates were recovered from 18 healthy cows （61 isolates） and 25 cows with clinical endometritis （84 isolates） at 25-35 days after parturition. Genomic characteristics including phylogenetic grouping, genetic diversity and virulence genes of E. coli isolates were screened to profile the characteristics related to uterine infections. The susceptibility of the bacteria against 23 antibiotics was also evaluated to support prevention and treatment of clinical cases. Genetic diversity of E. coli identified by random amplification of polymorphic DNA （RAPD） revealed 103 clonal types, including 3 common types to unaffected cows and endometritis cows, 39 types specific to healthy cows and 61 types in endometritis subjects. In addition, the isolates from endometritis uteri showed more genetic variability compared with that of healthy cows. Ac- cording to the findings of phylogenetic grouping, the E. coil isolates were assigned to group A （35.9%）, B1 （59.3%） and D （4.8%）. The expression of 10 of 20 virulence gens were detected positively, and only fimH gene was revealed significantly （P〈0.05） associated with endometritis. From antimicrobial susceptibility test, E. coli was found highly resistant to tetracy- cline, ampicillin, carbenicillin and amoxicillin, but sensitive to amikacin, netilmicin, tobramycin, cefepime and ceftazidime. In conclusion, E. cofiwere extensively observed in both healthy and endometritis cows, and presented a large clonal types, however, fimH was the only gene observed associated with clinical endometritis. Our results suggest that the drugs like amikacin, netilmicin, tobramycin and cefepime could be considered for preventing and treating clinical endometritis in the practical management of dairy cow.

Prevalence and Antimicrobial Susceptibility Pattern of Streptococcus pneumoniae at General Hospital in the Central Region of Japan from December 2013 to February 2014

Streptococcus pneumonia infection is important cause of morbidity and mortality. This study was conducted to find out the prevalence and antimicrobial susceptibility pattern of Streptococcus pneumoniae isolates at general hospitalin the central region of Japan from December 2013 to February 2014. Streptococcus pneumoniae was identified by standard laboratory procedure. Antimicrobial susceptibility testing was performed by micro dilution assay according to CLSI recommendation. One hundred fifty-three Streptococcus pneumoniae were isolated among which 80 (52.2%) were males and 73 (47.8%) were females. Nasal discharge (134%/87.6%) contributed more than other biological materials. The age incidence of (0 - 1) years, (1 - 10) years, (11 - 40) years, (41 - 60) years and >60 years age groups were 26 (17.0%), 110 (71.9%), 3 (2.0%), 10 (6.5%), and 4 (2.6%) respectively. Positive samples were received mostly from the pediatrics (137%/89.5%), respiratory medicine (12%/7.8%) and lowest from gastroenterology (1%/0.6%) and neurology (1/ 0.6%) department. Vancomycin and rifampicin were the most active antibiotics with 100% susceptibility rates. The next best were levofloxacin, penicillin G and ceftriaxone. Our study revealed that 82 Streptococcus pneumonia isolates had multidrug resistant ability (53.6%). Streptococcus pneumoniae infection spreads among community easily and inappropriate use of antibiotics contributes to their resistance. Continuous antimicrobial susceptible surveys are essential to guide policy on the adequate use of antibiotics to reduce the morbidity and mortality and reduce the emergency of antimicrobial resistance.

Isolation and Identification of Four Strains of Salmonella and Drug Susceptibility Test

In order to isolate and identify the pathogenic bacteria causing dead chickens in a chicken farm in Qinhuangdao area, the liver, heart and other organs of dead chickens suspected of salmonella disease were collected aseptically, and streaked on SS agar medium and chromagar medium. Transparent colonies were observed on SS agar medium, and purple and transparent colonies on CAS medium. The isolate was conducted purification, staining microscopy, biochemical tests, and 16 S rRNA sequence analysis, and the results showed that four strains of the isolated bacte-ria were salmonella. The 16 S rRNA sequence analysis of four strains of salmonella showed that the isolates shared more than 99% homology. Drug susceptibility test was performed using paper method, and the results showed that most of the strains were resistant to tilmicosin, cefradine and sul-famethoxazole, but were sensitive to ceftriaxone.

Isolation, Identification and Drug Susceptibility Test of a Strain of Escherichia coli Causing Fox Pneumonia

[Objective] The paper was to determine the pathogen causing fox pneumonia in a breeding factory in Changli County.[Method]Through autopsy, a dominant strain was isolated from the lung of dead foxes, which was then performed Gram staining, 16 S rRNA sequence analysis and biochemical identification.[Result] The strain was negative in Gram staining, and was identified as E. coli through 16 S rRNA sequence analysis and biochemical identification. Drug susceptibility test was conducted using 15 kinds of drug susceptibility papers. The E. coli was sensitive to florfenicol, enrofloxacin, ceftriaxone, norfloxacin;intermediately sensitive to amikacin, gentamicin;and strongly resistant to penicillin, ampicillin,cefradine, sulfamethoxazole, lincomycin, streptomycin and amoxicillin.[Conclusion] It is difficult to treat E. coli causing fox pneumonia with traditional antibiotics clinically.

Antimicrobial Susceptibility Profiles among <i>Escherichia coli</i>Strains Isolated from Athi River Water in Machakos County, Kenya

Antimicrobial use in agriculture, livestock and human health has increased over the years leading to the increase in antimicrobial resistance that can also find its way to the aquatic environment. Rivers can act as reservoirs of highly resistant strains and facilitate the dissemination of multidrug resistant (MDR) strains to animals and humans using water. A total of 318 water samples were collected from six different sampling points along Athi River and E. coli isolates were subjected to Kirby-Bauer diffusion method for antimicrobial susceptibility testing. The total mean coliform count of the sampled sites was 2.7 × 104 (cfu/mL). E. coli isolates were most resistant to ampicillin (63.8%) and most susceptible to gentamicin (99.4%). MDR strains (resistance to ≥3 classes of antibiotics) accounted for 65.4% of all the isolates. The site recorded to have human industrial and agricultural zone activities had strains that were significantly more resistant to ampicillin, cefoxitin, amoxicillin/clavulanic acid (P ≤ 0.05) than isolates from the section of the river traversing virgin land and land with minimum human activities. This study indicates that E. coli strains isolated from Athi River were highly MDR and most resistant to some antimicrobial classes (ampicillin and cefoxitin) which constitute a potential risk to human and animal health.