Antimicrobial Resistance of EntericSalmonellain Bangui, Central African Republic

Introduction. The number ofSalmonellaisolated from clinical samples that are resistant to multiple antibiotics has increased worldwide. The aim of this study was to determine the prevalence of resistantSalmonella entericaisolated in Bangui.Methods. All entericSalmonellastrains isolated from patients in 2008 were identified and serotyped, and the phenotypes of resistance were determined by using the disk diffusion method. Nine resistance-associated genes,blaTEM,blaOXA,blaSHV,tetA,aadA1,catA1,dhfrA1,sul I, andsul II, were sought by genic amplification in sevenS.e. Typhimurium strains.Results. The 94 strains isolated consisted of 47S.e.Typhimurium (50%), 21S.e.Stanleyville (22%), 18S.e.Enteritidis (19%), 4S.e.Dublin (4%), 4S.e.Hadar (4%), and 1S.e.Papuana (1%). Twenty-five (28%) were multiresistant, including 20 of the Typhimurium serovar (80%). Two main phenotypes of resistance were found: four antibiotics (56%) and to five antibiotics (40%). OneS.e.Typhimurium isolate produced an extended-spectrumβ-lactamase (ESBL). Only seven strains ofS.e.Typhimurium could be amplified genically. Only phenotypic resistance to tetracycline and aminosides was found.Conclusion.S.Typhimurium is the predominant serovar of entericS. entericaand is the most widely resistant. The search for resistance genes showed heterogeneity of the circulating strains.

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Serotypes and antimicrobial resistance profiles of Salmonella enterica recovered from clinical swine samples

Veterinary World ◽

10.14202/vetworld.2020.2312-2318 ◽

2020 ◽

Vol 13 (11) ◽

pp. 2312-2318

Author(s):

Siriporn Kongsoi ◽

Suksun Chumsing ◽

Darunee Satorn ◽

Panisa Noourai

Keyword(s):

Public Health ◽

Antimicrobial Resistance ◽

High Resistance ◽

Salmonella Enterica ◽

Foodborne Pathogen ◽

Diffusion Method ◽

Clinical Samples ◽

Public Health Issue ◽

Diagnostic Laboratory ◽

Disk Diffusion Method

Background and Aim: Salmonella enterica is an important foodborne pathogen and is recognized as a major public health issue. The emergence of multidrug-resistant (MDR) S. enterica represents a major challenge for national public health authorities. We investigated the distribution of serovars and antimicrobial resistance of S. enterica isolates from clinical swine samples stored at the Veterinary Diagnostic Laboratory, Faculty of Veterinary Medicine, Kasetsart University from 2016 to 2017. Materials and Methods: Clinical samples were collected and subjected to standard microbiological techniques outlined in the Manual of Clinical Microbiology to identify Salmonella serovars. Susceptibility to antimicrobials was tested by the Kirby–Bauer disk diffusion method using a panel of 14 antimicrobials. Results: A total of 144 Salmonella isolates were identified and the dominant serovar was Salmonella Choleraesuis (66.67%), followed by monophasic Salmonella Typhimurium (18.75%), S. Typhimurium (9.03%), and Rissen (5.56%). The isolates displayed high resistance rates to ampicillin (AMP [100%]), amoxicillin (AX [100%]), tetracycline (TE [100%]), cefotaxime (CTX [89.58%]), ceftriaxone (CRO [87.50%]), chloramphenicol (C [82.64%]), gentamicin (CN [79.17%]), nalidixic acid (NA [72.92%]), and ceftazidime (CAZ [71.53%]). All isolates were MDR, with 29 distinct resistance patterns. The dominant MDR pattern among serovars Choleraesuis and Rissen exhibited resistance to 9 antimicrobials: ( R7-14 AMP-AX-CAZ-CRO-CTX-NA-C-CN-TE). However, all tested isolates were susceptible to AX/ clavulanic acid and fosfomycin. Conclusion: High resistance levels to the third generation of cephalosporins such as CAZ, CRO, and CTX highlight the need for careful and reasonable usage of antimicrobials in animals and humans, especially for S. Choleraesuis infections.

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Antimicrobial Resistance Profile of Citrobacter freundii Isolated from the First Bethune Hospital

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.268-270.1951 ◽

2011 ◽

Vol 268-270 ◽

pp. 1951-1953

Author(s):

Jian Cheng Xu ◽

Li Qiang Wang ◽

Jun Wang ◽

Qi Zhou

Keyword(s):

Antibiotic Resistance ◽

Antimicrobial Resistance ◽

Nosocomial Infections ◽

Disk Diffusion ◽

Diffusion Method ◽

Citrobacter Freundii ◽

Disk Diffusion Method ◽

Resistance Profile ◽

Antimicrobial Resistance Profile ◽

Multiple Antibiotics

Citrobacter freundii is important causes of nosocomial infections.The present study aimed to evaluate the antibiotic resistance profiles of Citrobacter freundii isolated from the First Bethune Hospital. Disk diffusion method was used to study the antimicrobial resistance. The data were analyzed by WHONET 5 software according to Clinical and Laboratory Standards Institute (CLSI). The majority of 432 strains of Citrobacter freundii were collected from sputum (240, 55.6%), secretions and pus (85, 19.7%), blood (58, 13.4%). All the Citrobacter freundii isolates were sensitive to imipenem and meropenem. Citrobacter freundii strains were frequently resistant to multiple antibiotics. The results suggest that surveillance of antimicrobial resistance in Citrobacter freundii is necessary.

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Antimicrobial Resistance Surveillance of Klebsiella Spp. Isolated from the First Bethune Hospital

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.268-270.1954 ◽

2011 ◽

Vol 268-270 ◽

pp. 1954-1956

Author(s):

Jian Cheng Xu ◽

Jun Han ◽

Yan Ling Yang ◽

Qi Zhou

Keyword(s):

Antibiotic Resistance ◽

Antimicrobial Resistance ◽

Nosocomial Infections ◽

Disk Diffusion ◽

Diffusion Method ◽

Opportunistic Pathogens ◽

Disk Diffusion Method ◽

Antimicrobial Resistance Surveillance ◽

Extended Spectrum ◽

Multiple Antibiotics

Klebsiella spp.are opportunistic pathogens which frequently cause community and nosocomial infections.The present study aimed to evaluate the antibiotic resistance profiles of Klebsiella spp. isolated from the First Bethune Hospital. Disk diffusion method was used to study the antimicrobial resistance. The data were analyzed by WHONET 5 software according to Clinical and Laboratory Standards Institute (CLSI). The majority of 3149 strains of Klebsiella spp. were collected from sputum（1890, 60.0%），blood（378, 12.0%） and secretions（315, 10.0%）. The percentage of extended-spectrum β-lactamases (ESBLs) in Klebsiellaspp. was 53.8% (1694/3149). Klebsiella spp. strains were frequently resistant to multiple antibiotics. Antimicrobial resistance of ESBL-producing Klebsiella spp. was more serious than that of non-ESBL-producing isolates. The results suggest that surveillance of antimicrobial resistance in Klebsiella spp. is necessary.

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Preliminary Results on the Prevalence of Salmonella Spp. in Marine Animals Stranded in Sicilian Coasts: Antibiotic Susceptibility Profile and ARGs Detection in the Isolated Strains

Pathogens ◽

10.3390/pathogens10080930 ◽

2021 ◽

Vol 10 (8) ◽

pp. 930

Author(s):

Delia Gambino ◽

Sonia Sciortino ◽

Sergio Migliore ◽

Lucia Galuppo ◽

Roberto Puleio ◽

...

Keyword(s):

Antibiotic Resistance ◽

Resistance Genes ◽

Antibiotic Susceptibility ◽

Antibiotic Resistance Genes ◽

Diffusion Method ◽

Salmonella Spp ◽

Marine Animals ◽

Disk Diffusion Method ◽

Phenotypic Resistance ◽

Low Prevalence

The presence of Salmonella spp. in marine animals is a consequence of contamination from terrestrial sources (human activities and animals). Bacteria present in marine environments, including Salmonella spp., can be antibiotic resistant or harbor resistance genes. In this study, Salmonella spp. detection was performed on 176 marine animals stranded in the Sicilian coasts (south Italy). Antibiotic susceptibility, by disk diffusion method and MIC determination, and antibiotic resistance genes, by molecular methods (PCR) of the Salmonella spp. strains, were evaluated. We isolated Salmonella spp. in three animals, though no pathological signs were detected. Our results showed a low prevalence of Salmonella spp. (1.7%) and a low incidence of phenotypic resistance in three Salmonella spp. strains isolated. Indeed, of the three strains, only Salmonella subsp. enterica serovar Typhimurium from S. coeruleoalba and M. mobular showed phenotypic resistance: the first to ampicillin, tetracycline, and sulphamethoxazole, while the latter only to sulphamethoxazole. However, all strains harbored resistance genes (blaTEM, blaOXA, tet(A), tet(D), tet(E), sulI, and sulII). Although the low prevalence of Salmonella spp. found in this study does not represent a relevant health issue, our data contribute to the collection of information on the spread of ARGs, elements involved in antibiotic resistance, now considered a zoonosis in a One Health approach.

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Staphylococci among Wild European Rabbits from the Azores: A Potential Zoonotic Issue?

Journal of Food Protection ◽

10.4315/0362-028x.jfp-19-423 ◽

2020 ◽

Vol 83 (7) ◽

pp. 1110-1114 ◽

Cited By ~ 1

Author(s):

MARGARIDA SOUSA ◽

VANESSA SILVA ◽

ADRIANA SILVA ◽

NUNO SILVA ◽

JESSICA RIBEIRO ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Resistance Genes ◽

Meca Gene ◽

Diffusion Method ◽

Coagulase Negative Staphylococci ◽

Spa Typing ◽

Disk Diffusion Method ◽

Genetic Lineages ◽

Antimicrobial Resistance Genes ◽

European Rabbits

ABSTRACT The prevalence and diversity of Staphylococcus species from wild European rabbits (Oryctolagus cuniculus) in the Azores were investigated, and the antibiotic resistance phenotype and genotype of the isolates were determined. Nasal samples from 77 wild European rabbits from São Jorge and São Miguel islands in Azores were examined. Antibiotic susceptibility of the isolates was determined using the Kirby-Bauer disk diffusion method, and the presence of antimicrobial resistance genes and virulence factors was determined by PCR. The genetic lineages of S. aureus isolates were characterized by spa typing and multilocus sequence typing. A total of 49 staphylococci were obtained from 35 of the 77 wild rabbits. Both coagulase-positive (8.2%) and coagulase-negative (91.8%) staphylococci were detected: 4 S. aureus, 17 S. fleurettii, 13 S. sciuri, 7 S. xylosus, 4 S. epidermidis, and 1 each of S. simulans, S. saprophyticus, S. succinus, and S. equorum. The four S. aureus isolates showed methicillin susceptibility and were characterized as spa type t272/CC121, Panton-Valentine leukocidin negative, and hlB positive. Most of the coagulase-negative staphylococci showed resistance to fusidic acid and beta-lactams, and multidrug resistance was identified especially among S. epidermidis isolates. The mecA gene was detected in 20 isolates of the species S. fleurettii and S. epidermidis, associated with the blaZ gene in one S. epidermidis isolate. Five antimicrobial resistance genes were detected in one S. epidermidis isolate (mecA,dfrA,dfrG,aac6′-aph2′′, and ant4). Our results highlight that wild rabbits are reservoirs or “temporary hosts” of Staphylococcus species with zoonotic potential, some of them carrying relevant antimicrobial resistances. HIGHLIGHTS

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Antimicrobial resistance in Salmonella enterica serovar Enteritidis in Morocco

The Journal of Infection in Developing Countries ◽

10.3855/jidc.806 ◽

2010 ◽

Vol 4 (12) ◽

pp. 804-809 ◽

Cited By ~ 4

Author(s):

Farida Ohmani ◽

Khadija Khedid ◽

Saad Britel ◽

Aicha Qasmaoui ◽

Reda Charof ◽

...

Keyword(s):

Antimicrobial Resistance ◽

Nalidixic Acid ◽

Salmonella Enterica ◽

Inhibitory Concentration ◽

Diffusion Method ◽

Salmonella Enterica Serovar Enteritidis ◽

Gastrointestinal Infections ◽

Disk Diffusion Method ◽

Resistance Patterns ◽

Resistance Rates

Introduction: Salmonella enterica is recognised worldwide as one of the major agents of human gastrointestinal infections. The aim of the present work is to ascertain the antimicrobial susceptibilities of 150 Salmonella enterica serovar Enteritidis isolates from humans in Morocco during the period from 2000 to 2008. Methodology: Antimicrobial resistance determination was performed by disk diffusion method using seven antibiotics. The minimal inhibitory concentration (MIC) of ciprofloxacin was determined for nalidixic acid-resistant (NAR) isolates using E-test strips. Results: Sixty-one (42%) isolates were resistant to at least one class of antimicrobial agent. The largest numbers of resistant isolates were observed for nalidixic acid with 53 isolates (36%) followed by ampicillin with 7 isolates (5%), tetracycline with 6 isolates (4%), and trimethoprim/sulfamethoxazole with 2 isolates (1%).The resistant isolates were grouped in seven different resistance patterns of which two isolates were resistant to three antibiotics. Among the 53 (36%) NAR isolates, 37 (76%) had a reduced susceptibility to ciprofloxacin. Conclusion: Resistance rates of Salmonella enterica serovar Enteritidis from Morocco are generally low but the resistance to nalidixic acid is worryingly common. Continual surveillance of antibiotic resistance is of primary importance.

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Antimicrobial Resistance and Virulence Determination of Enterococcus spp. Obtained from Hospital Environment in Iran

10.21203/rs.3.rs-123398/v1 ◽

2020 ◽

Author(s):

Saba Asgharzadeh Marghmalek ◽

Reza Valadan ◽

Mehrdad Gholami ◽

Mohtaram Nasrolahei ◽

Hamid Reza Goli

Keyword(s):

Antimicrobial Resistance ◽

Resistance Genes ◽

Pathogenic Bacteria ◽

Antibiotic Resistance Genes ◽

Hospital Environment ◽

Diffusion Method ◽

Virulence Determinants ◽

Environmental Isolates ◽

Disk Diffusion Method ◽

Antimicrobial Resistance Genes

Abstract Background: The role of the hospital environment as a source of pathogenic bacteria in recent studies has been poorly investigated. This study investigated the distribution of antimicrobial resistance genes and virulence determinants in Enterococcus species isolated from hospital environment in Sari, Iran. Method: Overall, 90 enterococci strains were obtained from high touch surfaces of four hospitals in Sari, Iran. These environmental samples were obtained from bathroom, beds, tables, doorknobs, room keys, wheelchair and walls in the patient and staff’s rooms. The resistance profile of the isolates was determined by disk diffusion method. Seven resistance genes and two virulence associated genes were evaluated molecularly by multiplex PCR. Results: According to the PCR, 42 (46.66%) of them were E. faecalis and 48 (53.33%) others were detected as E. faecium. Also, 28 (66.6%) E. faecalis and 18 (37.5%) E. faecium isolates were multidrug-resistant (MDR). Among all 90 environmental isolates 54 (60%), 54 (60%), 8 (8.8%), 8 (8.8%), 60 (66.6%), 26 (28.8%), and 24 (26.6%) isolates contained tetM, tetL, vanA, vanB, ermB, aac(6´)-Ie-aph(2´´)-Ia, and aph (3´)-IIIa, respectively. Moreover, all isolates were investigated for the presence of virulence genes and 88 (97.7%) of isolates had esp gene, and 16 (17.7%) had ace.Conclusions: This report showed that the environmental isolates of Enterococcus are the major sources of antibiotic resistance genes that can transfer them to the clinical isolates of bacteria in hospital settings. An effective following strategy should be organized to clearance and stop emergence of these pathogenic bacteria.

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Surveillance of antimicrobial resistance of maltose negative Staphylococcus aureus in South African dairy herds

10.21203/rs.2.18013/v3 ◽

2020 ◽

Author(s):

Joanne Karzis ◽

Inge-Marié Petzer ◽

Edward F. Donkin ◽

Vinny Naidoo ◽

Eric M. C. Etter

Keyword(s):

South Africa ◽

Staphylococcus Aureus ◽

Antimicrobial Resistance ◽

Disk Diffusion ◽

Diffusion Method ◽

Dairy Herds ◽

Disk Diffusion Method ◽

Milk Samples ◽

Kwazulu Natal ◽

Over Time

Abstract Background The discovery of antimicrobials in the 1930s was one of the greatest achievements in medicine. However, bacterial resistance to antimicrobials was already observed in the 1940s and has been reported since then in both human and veterinary medicine, including in dairy cows. Many years of monitoring milk samples in South Africa, has led to the identification of a new strain of Staphylococcus aureus (S. aureus), which is maltose negative and appears to be an emerging pathogen. In this study the differences in susceptibility to antimicrobials of this strain were evaluated over time, over different seasons, in different provinces, and according to somatic cell count (SCC) categories. Results A data set of 271 maltose negative S. aureus isolates, cultured from milk samples from 117 herds out of the estimated 2000 commercial dairy herds in South Africa between 2010 and 2017, was studied using the disk diffusion method. This analysis was done using the Clinical Laboratory Standards Institute (CLSI) breakpoints in order to compare using both the previous (Intermediate category grouped with Resistant) and current definitions, (Intermediate category grouped with Susceptible). The results of the analysis between the previous and the current definitions differed for tylosin, cefalonium, oxy-tetracycline and cloxacillin. Neither the analysis using the previous nor the current systems showed an effect of province for the maltose negative S. aureus. This was in contrast to the results for maltose positive S. aureus where differences between provinces were shown in a previous study, with the lowest prevalence of resistance shown in KwaZulu-Natal during spring. For the susceptibility testing of 57 maltose negative and 57 maltose positive S. aureus isolates from 38 farms, from KwaZulu Natal, Eastern Cape and Western Cape. The minimum inhibitory concentration (MIC) results for the maltose negative S. aureus isolates confirmed the results of the disk diffusion method. Conclusions The maltose negative strains of S. aureus differed in general, in their antimicrobial resistance patterns over time, in comparison to maltose-positive S. aureus strains. MIC testing also indicated that more multidrug -resistant isolates were seen with the maltose negative S. aureus than in the maltose positive strains.

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Comparative analysis of Bacillus cereus group isolates' resistance using disk diffusion and broth microdilution and the correlation between resistance phenotypes and genotypes

10.1101/2021.11.22.469644 ◽

2021 ◽

Author(s):

Emma Mills ◽

Erin Sullivan ◽

Jasna Kovac

Keyword(s):

Antimicrobial Resistance ◽

Bacillus Cereus ◽

Resistance Genes ◽

Disk Diffusion ◽

Broth Microdilution ◽

Beta Lactam ◽

Phenotypic Resistance ◽

Antimicrobial Resistance Genes ◽

Antimicrobial Resistance Gene ◽

Disk Diffusion Assay

A collection of 85 Bacillus cereus group isolates were screened for phenotypic resistance to nine antibiotics using disk diffusion and broth microdilution. The broth microdilution antimicrobial results were interpreted using the CLSI M45 breakpoints for Bacillus spp. Due to the lack of Bacillus spp. disk diffusion breakpoints, the results obtained with the disk diffusion assay were interpreted using the CLSI M100 breakpoints for Staphylococcus spp. We identified significant (p < 0.05) discrepancies in resistance interpretation between the two methods for ampicillin, gentamicin, rifampicin, tetracycline, and trimethoprim/sulfamethoxazole. Antimicrobial resistance genes were detected using unassembled and assembled whole-genome sequences with Ariba and Abricate, respectively, to assess the sensitivity and specificity for predicting phenotypic resistance based on the presence of antimicrobial resistance genes. We found antimicrobial resistance gene presence to be a poor indicator for phenotypic resistance, calling for further investigation of mechanisms underlying antimicrobial resistance in the B. cereusgroup. Genes with poor sensitivity and/or specificity, as determined based on broth microdilution results included rph(rifampicin, 0%, 95%), mphgenes (erythromycin, 0%, 96%), and all vangenes (vancomycin, 100%, 35%). However, Bc(ampicillin, 64%, 100%) andtet genes (tetracycline, 67%, 100%) were highly specific, albeit moderately sensitive indicators of phenotypic resistance based on broth microdilution results. Only beta-lactam resistance genes (Bc, BcII, and blaTEM) were highly sensitive (94%) and specific (100%) markers of resistance to ceftriaxone based on the disk diffusion results, providing further evidence of these beta-lactams' role in nonsusceptibility of Bacillus cereus group isolates to ceftriaxone.

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Campylobacteriosis Agents in Meat Carcasses Collected from Two District Municipalities in the Eastern Cape Province, South Africa

Foods ◽

10.3390/foods9020203 ◽

2020 ◽

Vol 9 (2) ◽

pp. 203 ◽

Cited By ~ 3

Author(s):

Aboi Igwaran ◽

Anthony I. Okoh

Keyword(s):

Resistance Genes ◽

Virulence Genes ◽

Diffusion Method ◽

Eastern Cape ◽

Disk Diffusion Method ◽

Potential Health ◽

Phenotypic Resistance ◽

Virulence Markers ◽

Campylobacter Species ◽

Meat Samples

Raw meats are sometimes contaminated with Campylobacter species from animal faeces, and meats have repeatedly been implicated in foodborne infections. This study evaluated the prevalence, virulence genes, antimicrobial susceptibility patterns, and resistance gene determinants in Campylobacter species isolated from retailed meat carcasses. A total of 248 raw meat samples were collected from butcheries, supermarkets, and open markets; processed for enrichment in Bolton broth; and incubated at 42 °C for 48 h in 10% CO2. Thereafter, the broths were streaked on modified charcoal cefoperazone deoxycholate agar (mCCDA) plates and incubated at the same conditions and for the same amount of time. After incubation, colonies were isolated and confirmed by Polymerase chain reaction using specific oligonucleotide sequences used for the identification of the genus Campylobacter, species, and their virulence markers. The patterns of antimicrobial resistance profiles of the identified isolates were studied by disk diffusion method against 12 antibiotics, and relevant resistance genes were assessed by PCR. From culture, 845 presumptive Campylobacter isolates were obtained, of which 240 (28.4%) were identified as genus Campylobacter. These were then characterised into four species, of which C. coli had the highest prevalence rate (22.08%), followed by C. jejuni (16.66%) and C. fetus (3.73%). The virulence genes detected included iam (43.14%), cadF (37.25%), cdtB (23.53%), flgR (18.63%), and flaA (1.96%), and some of the isolates co-harboured two to four virulence genes. Of the 12 antibiotics tested, the highest phenotypic resistance displayed by Campylobacter isolates was against clindamycin (100%), and the lowest level of resistance was observed against imipenem (23.33%). The frequency of resistance genes detected included catll (91.78%), tetA (68.82%), gyra (61.76%), ampC (55%), aac(3)-IIa (aacC2)a (40.98%), tetM (38.71%), ermB (18.29%), tetB (12.90%), and tetK (2.15%). There is a high incidence of Campylobacter species in meat carcasses, suggesting these to be a reservoir of campylobacteriosis agents in this community, and as such, consumption of undercooked meats in this community is a potential health risk to consumers.

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