Ampicillin Disks Research Articles

Ampicillin susceptibility testing of Haemophilus influenzae in the routine clinical laboratory by the EUCAST methodology compared to broth microdilution and the presence of ftsI gene mutations

ObjectivesTo investigate the prevalence of ampicillin resistance in Haemophilus influenzae and the diagnostic accuracy of the EUCAST recommended disc diffusion method to detect the increasingly prevalent ampicillin resistance due to the presence of PBP3 alterations based on mutations in the ftsI gene. MethodsDuring a 6-month period all consecutive non-duplicate H. influenzae isolates were prospectively collected and stored. MICs of ampicillin were determined by broth microdilution (BMD). PCR was performed to detect mutations in the ftsI gene. Results of routine disc diffusion susceptibility testing, including the penicillin screening test in accordance with the current EUCAST methodology, as well as additional Etest results, were compared to the BMD as the reference method. ResultsIn 102 isolates, the prevalence of ampicillin resistance was 28% (29/102) by BMD. There was a good correlation between MICs of ampicillin and the presence of a β-lactamase and/or an ftsI gene mutation. The prevalence of ampicillin resistance was overestimated using the EUCAST method (33% (34/102)) and underestimated when an additional Etest was used (24% (24/102)) (not significant). The sensitivity and specificity of the EUCAST methodology for the detection of ampicillin resistance were 97% ((28/29); 95% CI, 82–100%) and 92% ((67/73); 95% CI, 83–97%), respectively. ConclusionsThe prevalence of ampicillin resistance was 28%, as determined by BMD. Although the overall diagnostic accuracy of the EUCAST ampicillin disc diffusion was high, misclassification of ampicillin susceptibility may still occur.

The Effect of Lavender Essential Oil on Escherichia coli Growth and its Potential Applications

Escherichia coli (E. coli) infects millions worldwide annually, leading to thousands of deaths, particularly impacting those low to middle-income countries where E. coli can be found in contaminated soil, water, and surfaces (Winstead et al. 2019). In this investigation, lavender essential oil and ampicillin disks were tested against E. coli grown on an agar plate to see if they could be used as a potential antimicrobial agent in regions where E. coli infections are largely prevalent. Based on the Kirby-Bauer tests conducted in this investigation, lavender essential oil displayed a clear zone of inhibition, though it was relatively smaller than the zone of inhibition for ampicillin. Future applications to such findings could be to utilize lavender in both plant and essential oil form as a treatment for E. coli soil contaminations and a natural pest repellent, both in the agricultural industry and in regions where cost-effective, environmentally sustainable treatments may not currently exist.

Preliminary evaluation of probiotic properties and safety profile of Lactiplantibacillus plantarum isolated from spontaneously fermented milk, Amabere amaruranu

The aim of this study was to assess the probiotic potential and safety profile of a Lactiplantibacillus plantarum EGER41 strain isolated from Kenyan spontaneously fermented milk, Amabere amaruranu. The L. plantarum EGER41 isolate was tested for temperature sensitivity (at 15 °C, 30 °C, 37 °C, and 45 °C), pH tolerance (at 2.0, 2.5, 3.0, 3.5, and 6.5 as control), and 0.4% phenol tolerance to observe its survival in the gastrointestinal tract of humans. For safety evaluation of the isolate, antagonistic activity was tested against pathogenic strains of Staphylococcus aureus, Escherichia coli, Salmonella enterica serovar Typhi, and Candida albicans, while antibiotic susceptibility pattern was examined using nalidixic acid, ampicillin, azithromycin, ciprofloxacin, tetracycline, gentamicin, and chloramphenicol antibiotic discs and haemolytic activity was done using lamb blood agar. The L. plantarum isolate had an optimal growth at 37 °C, it also demonstrated low pH tolerance (2.0–3.5). It was able to maintain its viability (∼100%) after exposure to 0.4% phenol. The selected isolate showed inhibition (antagonistic activity) against the pathogens with S. typhi having the largest (ZDI = 31.0 ± 1.73 mm) zone of diameter inhibition (ZDI) and Candida albicans having the least (ZDI = 18.0 ± 0.76 mm). L. plantarum isolate was sensitive to Azithromycin, tetracycline and chloramphenicol and was intermediately sensitive to gentamycin, while it was resistant to nalidixic acid, ampicillin, and ciprofloxacin. The isolate also exhibited γ-haemolytic activity hence safe for use as a starter culture and was identified as a Lactiplantibacillus plantarum EGER 41 strain based on 16S rRNA gene sequencing. The selected isolate can potentially be used as a starter culture and a probiotic since it had excellent probiotic properties.

In-Vitro antibacterial activity of glass ionomer cements containing silver nanoparticles synthesized from leaf extract of Mentha piperita

Purpose: The aim of this study was to evaluate the antibacterial activity of glass ionomer cement incorporated with silver nanoparticles (AgNPs) synthetized using mint leaf extract (Mentha piperita, M. piperita) on some oral cavity bacteria.Materials and methods: In the present study, M. piperita leaf extract was used for the synthesis of AgNPs. A total of 60 glass ionomer cement (GIC) disk-shaped specimens were prepared and divided into two groups: conventional GIC (C-GIC), and glass ionomer cement with 2 wt% AgNPs (GIC-AGNPs). The antibacterial activity of the GIC specimens in comparison with Ampicillin disk (10 µg/ml) was investigated against Streptococcus mutans, Enterococcus faecalis, Lactobacillus acidophilus, Lactobacillus casei, and Streptococcus aureus by measuring the diameter of growth inhibition zones.Results: C-GIC specimens failed to show any antibacterial effect against the studied bacteria. However, the GIC-AgNPs had relatively significant antibacterial effects on S. mutans, L. acidophilus, L. casei and S. aureus. The highest antibacterial effect of GIC-AgNPs specimens was reported against L. acidophilus (P <0.001). GIC-AgNPs had no antibacterial effect on E. faecalis.Conclusion: Glass ionomer cement incorporated with AgNPs synthetized using M. piperita showed a promising antibacterial effect against oral cariogenic pathogens.

Phytochemical Investigation and Determination of Antibacterial Activity of Solvent Leave Extracts of Carissa spinarum.

BackgroundAmong many traditionally used medicinal plants, Carissa spinarum (Agam) is a well-known indigenous plant in Ethiopia. It is used in its raw form to treat different diseases in different parts of the country. Therefore, the aim of this study is to investigate extraction, isolation, and determination of the antibacterial properties of the solvent leaf extract of Carissa spinarum.MethodsIn this study, 800 g of powdered leaves of Carissa spinarum were macerated with 2500 mL of methanol and yielded 58 g (7.25%, w/w) of gummy material. The extract was then further partitioned by using ethyl acetate and chloroform. The extracts were subjected to phytochemical screening test. The antibacterial activity of the three solvent leaf extracts of Carissa spinarum were evaluated using disc diffusion method. The methanol extract was subjected to column chromatography silica gel (60–200 mesh) by mixing methanol:petroleum ether (4:1). Then fractions were collected and investigated by TLC and finally identified using spectroscopy.ResultsThe three extracts (methanol, ethyl acetate, and chloroform) of Carissa spinarum were presented to antimicrobial activity by disc diffusion method against four bacterial species using gentamycin and ampicillin discs as positive controls and DMSO as a negative control. All extracts had a relatively antibacterial effect with different extent zones of inhibition. However, the methanol extract showed superior antibacterial activity compared with DMSO and ethyl acetate and chloroform extracts. These could due to variation of the phytoconstituents. The most probable structure of the compound isolated was 5-(2’,3’,4’,6’-tetrahydroxy-5’-methoxycyclohexyloxy)-2,3,4 trihydroxypentanoic acid.ConclusionData obtained from this study collectively indicated that the three solvent extracts of Carissa spinarum have a promising antimicrobial activity which supports the traditional claim of the plant for treatment of infection.

Impact of antibiotic withdrawal and starvation conditions on plasmid elimination and consequent loss of resistance.

To assess resistance-loss due to plasmid elimination under experimental conditions, including withdrawal of antibiotics and administration of starvation conditions. The experimental study was conducted at the Department of Pathology, King Edward Medical University, Lahore, Pakistan, from July to December 2019. A single sensitive clinical isolate of escherichia coli, showing resistance towards ampicillin was collected and separately sub-cultured in three different culture broths: tryptic soya broth, minimal broth and control broth for a period of one month under standard laboratory conditions. Minimum inhibitory concentrations of the strains were calculated after every seven days to check antibiotic susceptibility. Minimum inhibitory concentrations of the initial escherichia coli strain measured on Day 1 was 6mg/mL and it became sensitive after continual sub-culturing in the absence of antibiotics in 21 days. Due to starvation conditions, the bacterial strain exhibited sensitivity to an even lower antibiotic concentration of 1.5mg/mL on the 28th day. Bacterial growth inhibition zones determined by disc diffusion method using an ampicillin disc of 10µg/mL showed no zone of inhibition. Provision of starvation conditions and withdrawal of antibiotic allowed the escherichia coli strain to exhibit gradual loss of resistance over a period of time.

Antagonistic, Anti-oxidant, Anti-inflammatory and Anti-diabetic Probiotic Potential of Lactobacillus agilis Isolated From the Rhizosphere of the Medicinal Plants.

Potential probiotic bacteria can be used as a biotherapeutic agent and a sustainable alternative to antibiotics, as an anti-oxidative, anti-inflammatory, and anti-diabetic agent without causing any serious side effects. Mostly human-friendly Lactic acid bacteria (LAB) have been isolated from the animal-human origin to be used as biotherapeutic agents or to produce useful metabolites (nutraceutical). However, less information is known about the role of medicinal plants associated LAB as biotherapeutic agents. The isolation of 115 human-friendly Lactobacillus strains was done from the rhizosphere of the medicinal plants Ocimum tenuiflorum, Azadirachta indica, Ficus carica. The obtained bacteria were then tested for their safe status before being using it for a beneficial purpose. Out of 115 strains, 29 (25%) were negative for blood hemolytic activities. Among these 29 isolates, three isolates did not show a breakdown of gelatin and were recognized as safe. Antibiotic resistance assay showed resistance of two of them against antibiotics discs of Streptomycin (10µg), Ciprofloxacin (20µg), Vancomycin (30µg), Metronidazole (10µg), Ampicillin (5µg), Chloramphenicol (30µg), Kanamycin (30µg), Erythromycin (15µg), Penicillin (10µg) and Tetracycline (30µg). The bacterial isolate (T-2) was found safe that was identified as Lactobacillus agilis by sequence analysis of 16s rRNA gene and processed in vitro as an anti-bacterial, anti-oxidant, anti-diabetic, and anti-inflammatory agent. Free radical scavenging activities and inhibition of α-amylase activities for Lactobacillus agilis were found relative to standard drug values as 68% and 73% and 51.3% and 65.3%, respectively. The in-vitro anti-inflammatory assay showed 61.6% (Lactobacillus agilis) while showed 69% (aspirin) activity for denaturation albumin protein. The results suggested that Lactobacillus agilis can be used as a potential probiotic strain as well as can be used to produce nutraceuticals.

Frequency of CTX-M gene isolated from E. coli in patients with suspected urinary tract infection in Semnan

Background and objectiveToday, bacterial resistance is one of the greatest medical challenges and it annually serves a huge amount of public and private investments since late or false diagnosis endangers the lives of patients. Beta-lactamase genes are a major cause of this challenge. The aim of the current study was to investigate the pattern of bacterial resistance in patients with urinary tract infection (UTI) in Semnan and to determine the frequency of CTX-M gene. Materials and methodsThroughout the study, 400 samples of urine were collected from healthcare centers and clinical laboratories in Semnan. Then, 151 E. coli positive samples were isolated through diagnostic and confirmatory tests. Antibiogram was performed using ampicillin, nalidixic acid, ceftriaxone, nitrofurantoin, co-trimoxazole, norfloxacin, amikacin, gentamicin and ciprofloxacin antibiotic discs. Ceftriaxone-resistant isolates were selected for the second stage of antibiogram. ESBL containing strains were identified and were investigated for CTX-M gene by PCR. ResultsThe sensitivity to nitrofuratoeine antibiotic was 35.76%% (n = 54) and the lowest sensitivity was to ampicillin (7.28%, n = 11). The rate of ESBL containing strains was 33, of which 60.6% contained CTX-M gene. Among the ESBL containing strains, the highest resistance was seen to be for ampicillin (n = 30). ConclusionDue to the high percentage of resistance to ampicillin in this area, prescribing by physicians must be prohibited; in addition, more attention should be paid to the use of other antibiotics, especially third generation of cephalosporins because of high prevalence of ESBL producers like blaCTX-M.

Probiotic Properties and Safety Profiling of <i>Lactobacillus plantarum</i> Isolated from Spontaneously Fermented Milk in Kenya

The aim of this study was to assess the probiotic potential and safety profile of a Lactobacillus plantarum strain isolated from Kenyan spontaneously fermented milk, Amabere amaruranu. The Lactobacillus plantarum isolate was tested for temperature sensitivity (at 15°C, 30°C, 37°C, and 45°C), pH tolerance (at 2.0, 2.5, 3.0, 3.5, and 6.5 as control), and 0.4% phenol tolerance to observe its survival in the gastrointestinal tract of humans. For safety evaluation of the isolate, antagonistic activity was tested against pathogenic strains of Staphylococcus aureus, Escherichia coli, Salmonella enterica serovar Typhi, and Candida albicans, while antibiotic susceptibility pattern was examined using nalidixic acid, ampicillin, azithromycin, ciprofloxacin, tetracycline, gentamicin, and chloramphenicol antibiotic discs and haemolytic activity was done using lamb blood agar. Lactobacillus plantarum isolate had an optimal growth at 37°C, it also demonstrated low pH tolerance (2.0–3.5). It was able to maintain its viability (~100%) after exposure to 0.4% phenol. The selected isolate showed inhibition (antagonistic activity) against the pathogens with S. typhi having the largest (ZDI = 31.0 ± 1.73 mm) zone of diameter inhibition (ZDI) and Candida albicans having the least (ZDI = 18.0 ± 0.76 mm). Lactobacillus plantarum isolate was sensitive to Azithromycin, tetracycline and chloramphenicol and was intermediately sensitive to gentamycin, while it was resistant to nalidixic acid, ampicillin, and ciprofloxacin. The isolate also exhibited γ-haemolytic activity hence safe for use as a starter culture. The selected isolate can be used as a starter culture and a probiotic since it had excellent probiotic properties.

Prevalence and antibiotic susceptibility pattern of Escherichia coli O157:H7 isolated from harvested fish at Lake Hayq and Tekeze dam, Northern Ethiopia

Fisheries play a significant role in food security, livelihood, and source of income in developing countries. Although fish are a healthy source of protein, they can also spread diseases caused by pathogenic micro-organisms they may harbor. Epidemiology of foodborne pathogens is not well studied in Ethiopia. To address this issue to some extent, a cross-sectional study with a simple random sampling approach was conducted from October 2017 to May 2018 with the objectives of to isolate and estimate the prevalence of Escherichia coli O157: H7 in fish, and to evaluate the antimicrobial susceptibility pattern of the isolates in selected Lakes of Northern Ethiopia. All the microbial identification and isolation procedures were conducted based on ISO 6887-3:2017 recommendations. Antimicrobial susceptibility test was also performed following the standard procedure of Kirby-Bauer disk diffusion protocol. From the total 410 fish samples examined, six (1.46%) of them were found contaminated with Shiga toxin-producing Escherichia coli O157: H7 strain. The organism was isolated from landing sites (5/293) and local retail markets (1/75). Besides, Escherichia coli O157: H7 was isolated from filleted fish (5/214) and whole fish (1/125); however, it was not isolated from samples of ready to eat fish and working environments of restaurants. The antibiotic susceptibility test revealed that the isolates were resistant to Ampicillin and Streptomycin disks. However, Ciprofloxacin, Gentamicin and Nalidixic acid were found effective in inhibiting the growth of all of the isolates. Since pathogenic Escherichia coli strain was detected from fish, raw and undercooked fish consumption in Ethiopia may result in contracting infections. The occurrence of such pathogenic organisms in fish indicates the need for intervention by stakeholders. Supports like freezers, generators, the establishment of fish processing plants and on job training about proper fish handling practices may play a tremendous role in decreasing the level of contamination of fish in Ethiopia.

Comparison of the Effects of Cytotoxicity and Antimicrobial Activities of Self-adhesive, Eugenol and Noneugenol Temporary and Traditional Cements on Gingiva and Pulp Living Cells

Aims and objectives: The aim of this in vitro study was to investigate the antibacterial and cytotoxic effect of cements: zinc polycarboxylate, glass ionomer, self-adhesive resin cement, eugenol-containing and eugenol-free temporary cements. Materials and methods: The agar-diffusion test was carried out on 4 types of bacteria: Streptococcus mutans ( S. mutans; ATCC 35668), Streptococcus salivarius ( S. salivarius; ATCC 13419), Streptococcus sangius ( S. sangius; ATCC 10556), and Lactobacillus casei ( L. casei; ATCC 27139). Freshly prepared cement samples were placed on a brain heart infusion medium and left at 37°C for 24 hours in a CO2 incubator. Ampicillin disks of 10 mg were used as positive controls. Antimicrobial effects were determined using the zone of inhibition measurement in millimeters at 24 and 48 hours. Cytotoxicity was assessed through a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (SERVA Electrophoresis GmbH, Heidelberg, Germany). To evaluate cell viability, an optical density microplate reader (Tecan™ Sunrise, Männedorf, Switzerland) was used at 24 and 48 hours at 570 and 630 nm, respectively. Results: Except the positive control group, the Adhesor luting cement showed a higher inhibitory effect on S. sangius and L. casei. RelyX Temp E temporary cement showed an inhibitory effect on S. sangius and L. casei, whereas the Cavex temporary cement showed an inhibitory effect on only S. sangius at 24 and 48 hours. At 100% concentration, Cavex temporary cement showed the least toxicity (23.6% pulp cell and 9.9% gingival cell) and highest cell viability (76.4% pulp cell and 90.1% gingival cell) at 24 hours. However, Meron, Adhesor, Panavia SA luting, and RelyX Temp E temporary cements showed the highest toxicity (above 94% gingival cell and 95% pulp cell) at 100% concentration. Conclusions: Meron, Adhesor, Panavia SA luting, and RelyX Temp E temporary cements may have a cytotoxic potential. None of the cements showed an inhibitory effect on S. mutan and S. salivarius, whereas Adhesor luting cement has a higher inhibitory effect than that of S. sangius and L. casei.

Prevalence of various enterococcus species and their antibiotic resistance pattern among urinary isolates in tertiary care center in South Eastern Rajasthan

Abstract Introduction: In 1899 Thiercelin first described ‘Enterococcus’. They are primarily member of gastrointestinal flora of human and animals. Enterococcus was grouped under streptococcus as group D streptococci but now it has been separated as individual genus. Clinically the most important species associated with human Infections are E. faecalis and E. faecium. They are frequently resistant to various group of antimicrobials. UTI is the most common infection among all Enterococcal infections and implicated in approximately 10 percent of all UTIs. Materials and Methods: The samples were collected from all hospitalized and OPD patients of MBS Hospital, JK Lone Hospital & NMC Hospital. Government Medical College, Kota, Rajasthan. A total of 360 isolates were collected during the period of 2 years from April 2016 to April 2018 and processed at Microbiology Laboratory, Department of Microbiology, Government Medical College, Kota, Rajasthan. Results: The present study shows a high incidence of enterococcal UTI among females (225) compare to males (135) with maximum Isolation among population between age group of 31- 40 (111) followed by 41-50 (59) and 21-30 (48). In present study the Ampicillin, Piperacillin, Ciprofloxacin, Norfloxacin, Nitrofurantoin, Gentamicin, Vancomycin and Linezolid antibiotic discs was tested and Linezolid was found to be most effective among all followed by Vancomycin, Nitrofurantoin, Ampicillin, Piperacillin, Ciprofloxacin, Norfloxacin. High level Gentamicin resistance (HLAR) was 60.27% in present study and Vancomycin resistance was 14.16 %. Conclusion: Among all species of enterococci E. faecium were most resistant species among all. Ampicillin & Piperacillin resistance was considerably higher in present study in comparison to other studies. Resistance to Nitrofurantoin was also found highest among E. faecium 77.77% in present study and other compared studies.[1] By observing the various parameters of present study it ca

Preliminary Studies on Isolation, Bile Tolerance and Antibiogram of Potential Probiotics (Probionts) from Locally Fermented Food Products at Beach Market, Nsukka Metropolis, Enugu State, Nigeria

Aims: The study aims to isolate, evaluate bile tolerance and antibiogram studies of potential probiotics (Lactobacillus spp) from locally fermented Food Products (Akamu, Aqua Rafa® Yoghurt, Ogiri, Okpeye) and Kunu at Beach Market, Nsukka.
 Study Design: A ten - fold serial dilution and spread plate method using De Man, Rogosa and Sharpe (MRS) medium was adopted for isolation of potential Probionts.
 Place and Duration of Study: Department of Pharmaceutical Microbiology and Biotechnology, Faculty of Pharmaceutical Sciences, University of Nigeria Nsukka, between March - September, 2018.
 Methodology: Only catalase negative and Gram positive isolates characteristic of lactobacilli were used. Bile tolerance test was performed by monitoring the bacterial growth at different Bile salt concentrations (0.2%, 0.3% and 2%). The antibiogram of the isolates was assessed using the Kirby-Bauer disc diffusion method against commercial antibiotic discs of ampicillin, vancomycin, gentamycin, ciprofloxacin, methicillin and erythromycin.
 Results: All the 18 screened isolates were tolerant to bile salt at 0.2 % and 0.3 % with inhibition of growth at 2 % bile concentration. All isolates were observed to be resistant to methicillin (100 %) but very sensitive to gentamycin (11%) and ciprofloxacin (22%) respectively. The isolates showed intermediate resistance to other antibiotics: vancomycin (33%), erythromycin (33%) and ampicillin (44%). The decreasing pattern of resistance was thus: methicillin > ampicillin > vancomycin and erythromycin > ciprofloxacin > gentamycin. Isolates from Yoghurt (66.67%) and Ogiri (53.33%) provided most of the resistant isolates. Methicillin would provide best antagonist potential as all the isolates exhibited very high level of resistance (100 %).
 Conclusion: These results suggest that all the eighteen potential Lactobacillus spp strain show potential for probiotic applications and the locally fermented food products are rich sources of probionts.

IN VITRO ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIES OF AQUEOUS AND ETHANOLIC LEAF EXTRACTS OF ACACIA AURICULIFORMIS

Objective: The present study focuses on in vitro antimicrobial properties of aqueous and ethanol leaf extract of Acacia auriculiformis tested on Gram-positive cocci, Gram-negative bacilli, multidrug-resistant (MDR) Gram-negative bacilli, and fungus.Methods: Ethanol and aqueous extracts of the leaves of A. auriculiformis were prepared. Agar well diffusion was the method for antimicrobial susceptibility. Freshly grown standard strains of Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumoniae (K. pneumoniae) , Escherchia coli (E.coli) and Pseudomonas aeruginosa, clinical strains of Streptococcus pneumoniae, Candida albicans (C. ailbicans), and MDR E. coli, and MDR Klebsiella pnuemoniae were used. Ampicillin disc (10 μg) was used as control.Results: The zone of inhibition was measured to determine the antimicrobial activity. Ethanolic extract of A. auriculiformis exhibited antibacterial activity against all the strains including MDR strains of K. pneumoniae and E. coli. Antifungal activity was exhibited by both aqueous and ethanol leaf extracts of A. auriculiformis.Conclusion: Ethanol extract could be used against MDR K. pneumoniae and MDR E. coli. Similarly, aqueous and ethanol extract can be the drug of choice for C. albicans infection. Further study is necessary to evaluate the accurate compound responsible for antibacterial and antifungal activity for pharmaceutical applications.

Frecuencia y Susceptibilidad Antimicrobiana de Bacterias Causantes de Mastitis en Bovinos de un Establo de Trujillo, Perú

Se determinó la frecuencia y susceptibilidad antimicrobiana de bacterias causantes de mastitis en bovinos de un establo del distrito de Conache, Trujillo, Perú, entre septiembre y diciembre de 2015. Se recolectaron muestras de leche de 140 cuartos individuales de 35 vacas que se les hizo el control de mastitis mediante observación directa y taza de fondo negro. Para el análisis microbiológico se sembraron las muestras en agar sangre y agar Mac Conkey y se incubaron a 37 °C por 24 h. Para determinar las bacterias gram positivas se realizaron pruebas de catalasa, coagulasa, fermentación de manitol y hemólisis; y para las gram negativas se realizaron pruebas de agar-hierro-triple azúcar (TSI), agar lisina-hierro (LIA), citrato de Simmons, ureasa, formación de indol, rojo metilo, Voges Proskauer y caldo glutamato. La susceptibilidad antimicrobiana se determinó mediante el método de Kirby-Bauer con discos de ampicilina, clindamicina, doxiciclina, eritromicina, estreptomicina, gentamicina, oxacilina y rifampicina. Se detectaron 31 vacas con mastitis bacteriana, donde el 76% presentó bacterias gram negativas y 24% gram positivas. Las bacterias gram negativas más frecuentes fueron E. coli (28%) y Klebsiella sp. (24%), y la bacteria gram positiva más frecuente fue Staphylococcus aureus (16%). Pseudomonas aeruginosa fue resistente a la mayoría de antibióticos, excepto a la eritromicina (susceptibilidad intermedia). E. coli presentó susceptibilidad intermedia a la eritromicina y resistencia a la oxacilina y rifampicina. Staphylococvcus aureus presentó susceptibilidad intermedia a la clindamicina y eritromicina y resistencia a la ampicilina.

Characterization of high level ampicillin- and aminoglycoside-resistant enterococci isolated from non-hospital sources.

High level ampicillin- and aminoglycoside-resistant enterococci are being increasingly reported from non-hospital sources. This study was carried out to characterize these strains from non-hospital sources in Nigeria. A collection of Enterococcus faecium isolated from vegetables, soil, farm animals and manure and observed to be resistant to ampicillin (n=63) and gentamicin (n=37) discs, were screened for resistance to high levels of ampicillin and aminoglycoside using E-test strips. Putative high level ampicillin- and aminoglycoside-resistant strains were screened for pbp5 and aminoglycoside modifying enzyme genes, respectively, by PCR. The C-terminal region of the amplified pbp5 gene was also sequenced. Five (5/63) and thirty-five (35/37) of the ampicillin- and aminoglycoside-resistant strains were identified as high level ampicillin- and aminoglycoside-resistant E. faecium strains, respectively, based on the MIC results. The amplified pbp5 gene from the high level ampicillin-resistant isolates displayed 96-99 % nucleotide sequence similarity with the reference strains and three novel insertions (500Glu→Leu, 502Asp→Arg and 614Ile→Phe) in the amino acid sequence. Aminoglycoside modifying enzyme genes aac(6')-Ie-aph(2″) (100 %), aph(2')-Ic (88.8 %), aph(3')-IIIa (90 %) and ant(4')-Ia (40 %) were detected among the high level aminoglycoside-resistant isolates. This is the first report on the characterization of high level ampicillin- and aminoglycoside-resistant Enterococcus faecium among animals and vegetables in Nigeria. The results show that non-hospital sources can constitute a reservoir for potential dissemination of these strains and genes to humans via the food chain or by direct contact.

Antibiotic Resistance, Plasmids and Integron Profile of Salmonella Species Isolated from Poultry Farm and Patients

A total of ten selected strains of Salmonella species, five from the environment of poultry farm and five from patients were included in this study. All strains were isolated and identified by using selective media, standard biochemical and serological tests. Antimicrobial susceptibility tests were performed by disc diffusion method using twelve commercial antibiotic discs of aztreonam, ceftriaxone, kanamycin, ciprofloxacin, gentamycin, chloramphenicol, ampicillin, erythromycin, cephalexin, tetracycline, cotrimoxazole and nalidixic acid. Plasmid profile and integron gene detection were conducted by Kado-Liu method and PCR, respectively. Only aztreonam, ceftriaxone, kanamycin and gentamycin were shown to be inhibitory to all strains. However, ciprofloxacin, chloramphenicol, amoxicilin, erythromycin, cephalexin, tetracycline, cotrimoxazole and nalidixic acid revealed different degrees of resistance pattern against environmental and clinical strains. Analysis of plasmid demonstrated that three environmental strains contained both plasmids of 140 Mda and 62 Mda. On the other hand, another three strains, one environmental and two clinical isolate only contained 140 Mda plasmid. All the plasmid containing strains (140 Mda and 62 Mda) exhibited same type of drug resistance pattern, whereas strains containing the 140 Mda plasmid only did not show similar type of resistance pattern. Therefore, no correlation was found between plasmid containing strains and drug resistance. Four environmental strains were also found to be positive for the class I integron and one clinical isolated was positive for class I integron gene conferring resistance to common antibiotics. However, none of the strains were found to contain class II integron. Therefore, the present study demonstrated that both environmental and clinical strains contain both large to middle size plasmids and integron I but not integron II. The plasmid and integron I containing strains experienced resistance to different antibiotics, used in the experiments.Dhaka Univ. J. Pharm. Sci. 15(2): 209-214, 2016 (December)

Beta-lactam resistance in enterobacteria isolated from animal and water

The susceptibility to β-lactam antibiotics was analysed in thirty seven strains of enterobacteria from both animals and non-chlorinated water of rural areas from Corrientes, North-eastern Argentina. Twenty nine were isolated from animals: Klebsiella pneumoniae (n=9), Klebsiella oxytoca (n=1), Proteus mirabilis (n=7), Escherichia coli (n=12), and 8 from non-chlorinated water: E. coli (n=5), K. pneumoniae (n=2), K. oxytoca (n=1). The antibiograms were performed by the Kirby-Bauer technique using antibiotic discs of ampicillin, cefotaxime, cefepime, piperacillin and with β-lactamases inhibitors: clavulanic acid-amoxicillin, sulbactam- cefoperazone and tazobactam-piperacillin. Carbapenems with an EDTA disc as metallo β-lactamases inhibitor were also used. Neither phenotypically ESBL (extended-spectrum beta-lactamases) nor carbapenemase were detected. It can be inferred that the resistance observed in this assay may be attributed to a different source.

Isolation of Bacteria From Sub-Clinical Cases in Mastitic She-Camel (Camelus Dromedaries) and Their Sensitivity to Some Antibiotics

The objective of this study was to determine the bacteria associated with mastitis in she- camel and to evaluate the sensitivity of these bacteria to antibiotics. Three hundred and thirty seven milk samples were collected from she- camel from Red Sea state and examined by WST, 40(11.87%) were positive and 297(88.13%) were negative. From the positive samples 115 organism were isolated. Isolation and identification of the bacteria is according to a standard cultures technique. It resulted in that the most predominant cause of she-camel mastitis is Staphylococcus spp. (74%). The other causes were Streptococcus spp.(15%), Corynebacterium spp.(1%), Anaerobic cocci spp.(2%), Bacillus spp.(4%),and Micrococcus spp.(4%).The Staphylococcus spp. isolated were S.aureus (58.07%), S.epidermidis(1.74%),S.hyicus (2.61%),S.simulans (0.87%), S. warnei (1.74%), S.lominis (0.87%), S.kloosii (5.22%), S.sciuri (0.27%) and S.lentus (2.61%) The sensitivity of these bacterial isolates to antibiotics was done using Oxoid discs of Ampicillin, Erthomycin, kanamycin, Streotomycin, tetracycline, chloramphenicol, Gentamycin and nalidixic acid. The organisms were considered sensitive or resistant according to zone size.The bacteriostatic and bactericidal activity of each drug was done. The results of the sensitivity test showed that the Staphylococcus spp. were highly sensitive to Ampicillin, Tetracycline and Gentamycin, while they are resistant to Erythromycin and Nalidixic acid. The Streptococcus aglactiae, Strep.dysglactiae and Strep uberis were sensitive to all tested antibiotic preparations, but resistant to Nalidixic acid antibiotic. The sensitivity of other isolates was not significant compared to the major isolates. It is concluded that the most dominant cause of mastitis in she- camels of the Red-Sea State of Sudan is Staphylococcus spp. and the most effective antibiotics against most of the isolated organisms are Tetracycline, chloramphenicol Gentamycin, Ampicillin and kanamycin.

PERBANDINGAN UJI RESISTENSI BAKTERI STAPHYLOCOCCUS AUREUS TERHADAP OBAT ANTIBIOTIK AMPISILIN DAN TETRASIKLIN

Staphylococcus aureus is one of the normal flora in the oral cavity, but these bacteria can change to be pathogen if there are predisposing factors such as changes in quantities of bacteria and decreasing of the immune response of the body. One of the ways to prevent is to inhibit the activity of these bacteria using antibiotics. Ampicillin and tetracycline are the broad-spectrum antibiotics that can inhibit the growth of positive and negative gram bacteria. This research was a laboratory experimental with Kirby-Bauer method and using CLSI standard. Total sample are 16 discs of ampicillin and 16 discs of tetracycline then placed on MHA media contain Staphylococcus aureus to see the inhibition power. The result showed that the averages of inhibition zone of ampicillin is 36,64 mm while tetracycline is 25,58 mm. Independent sample t- test showed that p<0,01 which means there is a significantly difference between ampicillin and tetracycline. Ampicillin and tetracycline can inhibit the growth of Staphylococcus aureus with sensitive categories. Ampicillin is more sensitive and effective than tetracycline to inhibit the growth of Staphylococcus aureus