Evaluación de la resistencia a los antibióticos de cepas de Escherichia coli aisladas en carne de cerdo comercializada en los mercados municipales de la ciudad de Guatemala / Evaluation of antibiotics resistance of Escherichia coli strains isolated in pork sold in municipal markets of Guatemala City

La resistencia a los antimicrobianos es un problema de salud pública a nivel mundial que va en aumento y se ve reflejada en la falta de eficacia de los tratamientos de infecciones bacterianas con antibióticos en humanos y en animales. El presente estudio tuvo como objetivo evaluar la resistencia a los antibióticos de cepas de Escherichia coli aisladas en carne de cerdo expendida en los mercados municipales de la ciudad de Guatemala. Se identificaron los antibióticos que presentaron mayor resistencia y mayor sensibilidad in vitro frente a las cepas de E. coli aisladas a partir de 76 muestras de carne de cerdo. Se realizó un muestreo aleatorio simple con afijación proporcional por mercado. Para la identificación de las cepas de E. coli se utilizó la prueba de IMViC y para evaluar la resistencia a los antimicrobianos se utilizó la prueba de Kirby Bauer empleando 9 antibióticos. Se aisló E. coli en el 55% (42/76) de las muestras. La resistencia en las 42 cepas aisladas fue: tetraciclina (83%) neomicina (50%) y sulfametoxasole + trimetoprim (50%). 83% de las cepas (35/42) fueron resistentes a 2 antibióticos y 50% (21/42) a 3 antibióticos o más. Se obtuvo mayor sensibilidad con ceftriaxona (91%), amikacina (83%), gentamicina (65%) y ácido nalidíxico (65%). Se concluye que existe resistencia a los antibióticos evaluados, lo que constituye un riesgo para la salud pública ya que se encuentra en cepas aisladas en un alimento para consumo humano.

Antimicrobial resistance is a global public health threat that is increasing and is reflected in the lack of efficacy of bacterial infection treatments with antibiotics in humans and animals. The objective of this study was to evaluate the resistance to antibiotics of Escherichia coli strains isolated from pork in the municipal markets of Guatemala City. Antibiotics with the highest resistance and those with the highest sensitivity in vitro against the strains of E. coli were evaluated. A simple random sampling was carried out with proportional allocation by market, and 76 samples were collected. IMViC test was used to identify the E. coli strains, and antibiotics resistance was evaluated using the Kirby Bauer with nine different antibiotics. E. coli was isolated in 55% (42/76) of the samples. Resistance was evaluated in the 42 isolates. Antibiotic resistance was detected to tetracycline (83%), neomycin (50%), and sulfamethoxazole + trimethoprim (50%). All isolates presented resistance to at least one antibiotic; it was determined that 83% (35/42) showed resistance to two antibiotics and 50% (21/42) showed resistance to three antibiotics or more. The sensitivity obtained was higher for ceftriaxone (91%), amikacin (83%), gentamicin (65%), and nalidixic acid (65%). In conclusion, antibiotic resistance was detected, which constitutes a risk to public health since it is found in isolated strains in food for human consumption.

Prevalence and characteristics of livestock-associated methicillin-susceptible Staphylococcus aureus in the pork production chain in Korea

The emergence and prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) in livestock animals have become a worldwide public health concern. While the prevalence and genetic profiles of MRSA strains in pigs and pork meat have been actively studied, livestock-associated MSSA strains have only been characterized in a few small-scale studies. In this investigation, we assessed the nationwide prevalence of MSSA in the Korean pig production chain, including pig farms, slaughterhouses, and retail markets. Among the 41 MSSA strains, the predominant clonal lineages were sequence type (ST) 398 (n = 15, 37%) and ST5 (n = 13, 32%). Although the overall prevalence of MSSA (2.58%) was low and mostly restricted to pig farms, ST398 MSSA strains showed higher level of multidrug resistance phenotype versus non-ST398 MSSA strains. In addition to the MDR phenotype, all of the ST398 MSSA strains exhibited resistance to tetracycline as they harbored the tet(K), tet(L), and/or tet(M) genes. However, ST398 MSSA strains did not exhibit increased resistance to zinc compared with the non-ST398 strains. This study is the first to provide evidence of ST398 MSSA emergence in livestock animals in Korea. Further studies are necessary to elucidate the potential of ST398 MSSA strains for human transmission. Our findings suggest that the MDR phenotype and high levels of tetracycline resistance may have played an important role in the emergence and prevalence of ST398 MSSA in pig farms in Korea.

Resistência de Neisseria gonorrhoeae a antimicrobianos na prática clínica: como está o Brasil? / Antimicrobials resistance of Neisseria gonorrhoeae in clinical practice: where Brazil stands?

Estima-se que um milhão de infecções sexualmente transmissíveis (IST) sejam adquiridas por dia no mundo, segundo a Organização Mundial da Saúde. Elas podem ser causadas por diversos micro-organismos pelo contato sexual. Embora tratáveis, as infecções, como a clamidiana, sífilis, tricomoníase e gonorreia, são responsáveis por 350 milhões de novos casos de IST anualmente no mundo. A gonorreia é a segunda IST bacteriana mais prevalente no planeta e tem chamado atenção nos últimos anos em decorrência da baixa eficácia em seu tratamento. O agente etiológico é a Neisseria gonorrhoeae. Na maioria das mulheres, a infecção por esse micro-organismo é assintomática, dificultando ainda mais seu diagnóstico e tratamento e, portanto, aumentando o risco de desenvolvimento de suas complicações associadas. Mesmo quando diagnosticada, essa infecção está sujeita a um alto índice de insucesso terapêutico que se deve, principalmente, à grande plasticidade genética da N. gonorrhoeae para aquisição de genes cromossômicos ou plasmidiais de resistência. O aumento da resistência desse micro-organismo a antimicrobianos comumente utilizados no tratamento, como penicilina, tetraciclina e ciprofloxacina, tem sido relatado em diversos países. No Brasil, poucos estudos estão disponíveis, mas em alguns estados já foram relatadas linhagens resistentes à ciprofloxacina. Dessa forma, deve-se ressaltar a importância de novos estudos que visem descrever o perfil da resistência da N. gonorrhoeae a antimicrobianos. Tais achados certamente nortearão a implementação de sistemas de vigilância epidemiológica no país visto que, até o momento, as infecções por N. gonorrhoeae sequer estão incluídas na lista nacional de doenças e agravos de notificação compulsória.(AU)

According to the World Health Organization, approximately one million sexually transmitted infections (STI) are acquired daily in the world. These infections can be caused by several microorganisms via contact. The treatable STI, such as chlamydia, syphilis, trichomoniasis and gonorrhea, account for 350 million new cases of STI each year worldwide. Gonorrhoea is caused by Neisseria gonorrhoeae and is the second most common bacterial STI in the world. It has drawn more attention in the last years due to the low efficacy in its treatment. Most women with this infection are asymptomatic, which makes its diagnosis and treatment troublesome increasing the risk for its associated complications. Even when diagnosed, this infection is subject to a high rate of therapeutic failure mainly due to the great genetic plasticity of N. gonorrhoeae for the acquisition of chromosomal or resistance plasmid enes. Increased resistance of this microorganism to antimicrobials commonly used in treatment such as penicillin, tetracycline and ciprofloxacin has been reported in several countries. In Brazil, few studies are available, but in some states strains resistant to ciprofloxacin were alreadyreported. The refore, it is important to highlight the importance of new studies aimed at describing the resistance profile of N. gonorrhoeae to antimicrobials in Brazil context. These findings will certainly guide the implementation of epidemiological surveillance systems in the country, since until now N. gonorrhoeae infections do not figure into the national list of compulsorily notifiable diseases.(AU)

Omadacycline, a Magic Antibiotics for Bacterial Infections

Nowadays antibiotic resistance is a worldwide serious problem that mainly affects public health. Omadacycline is a unique antibiotic which has two available dosage forms such as intravenous (IV) and oral that development for community-acquired bacterial infectious disease treatment. It is a modified form of older tetracycline at C-9 aminomethyl substituent of 6-member core ring of tetracycline. Modification form shows its activity against efflux pump and ribosomal protein protection mechanism of tetracycline resistance. Generally, omadacycline is effective against methicillin-resistant S. aureus (MRSA), Streptococcus pneumoniae, vancomycin-resistant Enterococcus (VRE), Legionella and Chlamydia spp. Efficacy, safety and tolerability profile of omadacycline those compares with recent antibiotics shows that omadacycline is less resistant than others. One derivative from tetracycline derivatives is 9-neopentylaminomethylminocycline called omadacycline was discovered and ongoing phase III clinical experiments as a therapy for acute bacterial skin and skin structure infections (ABSSSI) as well as community-acquired bacterial pneumonia (CABP). Omadacycline seems to be a strong drug candidate for future promising new antibacterial agent that is effective against ABSSSI and CABP.

Throat Carriage Rate and Antimicrobial Resistance of Streptococcus pyogenes In Rural Children in Argentina / 예방의학회지

OBJECTIVES: The aim of this study was to determine the prevalence of asymptomatic carriers of group A β-hemolytic streptococci (GAS) in children living in a rural community and to investigate the association between episodes of acute pharyngitis and carrier status. METHODS: Throat swabs were collected from September to November 2013 among children 5-13 years of age from a rural community (Maria Ignacia-Vela, Argentina). The phenotypic characterization of isolates was performed by conventional tests. Antimicrobial susceptibility was assayed for penicillin, tetracycline, chloramphenicol, erythromycin, and clindamycin (disk diffusion). The minimum inhibitory concentration was determined for penicillin, cefotaxime, tetracycline, and erythromycin. RESULTS: The carriage of β-hemolytic streptococci was detected in 18.1% of participants, with Streptococcus pyogenes in 18 participants followed by S. dysgalactiae ssp. equisimilis in 5. The highest proportion of GAS was found in 8 to 10-year-old children. No significant association between the number of episodes of acute pharyngitis suffered in the last year and the carrier state was detected (p>0.05). Tetracycline resistance (55.5%) and macrolide-resistant phenotypes (11.1%) were observed. Resistance to penicillin, cefotaxime, or chloramphenicol was not expressed in any streptococcal isolate. CONCLUSIONS: The present study demonstrated significant throat carriage of GAS and the presence of group C streptococci (S. dysgalactiae ssp. equisimilis) in an Argentinian rural population. These results point out the need for continuous surveillance of GAS and non-GAS carriage as well as of antimicrobial resistance in highly susceptible populations, such as school-aged rural children. An extended surveillance program including school-aged children from different cities should be considered to estimate the prevalence of GAS carriage in Argentina.

Caracterización de aislamientos nosocomiales de S. aureus en muestras purulentas en un hospital ortopédico en Cuba / Characterization of nosocomial isolates of S. aureus purulent samples in an orthopedic hospital in Cuba / Caractérisation des isolats nosocomiaux de S. aureus à partir des échantillons purulents dans un service d'orthopédie à Cuba

OBJETIVO: caracterizar microbiológicamente los aislamientos de Staphylococcus aureus recuperados a partir de muestras purulentas tomadas a pacientes con infecciones asociadas a la atención sanitaria en el Hospital Ortopédico Docente "Fructuoso Rodríguez" de enero a mayo de 2014. MÉTODO: estudio descriptivo realizado en el Hospital Ortopédico Docente "Fructuoso Rodríguez" de enero a mayo de 2014 en el que se analizaron 134 muestras de pacientes hospitalizados. El procesamiento de las muestras se realizó por métodos microbiológicos convencionales, y en aquellas donde se recuperó S. aureus se determinó la susceptibilidad antimicrobiana por el método de Bauer Kirby y de E-test para vancomicina. RESULTADOS: En 41,0 % de los aislamientos se identificó S. aureus. El 52,7 % de estos se obtuvieron de heridas quirúrgicas. Se encontró que 50,9 % de los aislamientos de S. aureus fueron meticillin resistentes. No se encontró ninguna cepa resistente a vancomicina. Los aislamientos de S. aureus meticillin resistentes resultaron ser significativamente más resistentes que los de S. aureus meticillin sensibles para eritromicina y las tetraciclinas (tetraciclina y doxiciclina). CONCLUSIONES: S. aureus resultó el microorganismo más encontrado en las muestras purulentas estudiadas. En los aislamientos hospitalarios S. aureus predominó en las heridas quirúrgicas lo cual está en correspondencia con la literatura revisada. La mitad de los aislamientos estudiados resultaron ser S. aureus meticillin resistentes. Todos los antimicrobianos testados, con excepción de vancomicina, mostraron mayores porcentajes de resistencia en los aislamientos meticillin resistentes que en los meticillin sensibles lo que representa un aumento en la estadía hospitalaria y en el costo de la atención médica en aquellos pacientes con S. aureus meticillin resistentes.

OBJECTIVE: microbiologically characterize isolates of Staphylococcus aureus recovered from purulent samples to patients with infections associated with health care at "Fructuoso Rodríguez" Teaching Orthopedic Hospital from January to May 2014. METHOD: a descriptive study was conducted at "Fructuoso Rodríguez" Teaching Orthopedic Hospital from January to May 2014 in which 134 samples from hospitalized patients were analyzed. Sample processing was performed by conventional microbiological methods and for those samples where S. aureus was recovered, antimicrobial susceptibility by the Kirby Bauer method and E-test was determined for vancomycin. RESULTS: 41.0 % of S. aureus isolates were identified. 52.7 % of these were obtained from surgical wounds. It was found that 50.9 % of the isolates were meticillin-resistant S. aureus. No vancomycin resistant strain was found. The isolates of meticillin-resistant S. aureus were significantly more resistant than S. aureus meticillin sensitive to erythromycin and tetracyclines (tetracycline and doxycycline). CONCLUSIONS: S. aureus was the microorganism most found in the purulent samples studied. In hospital S. aureus isolates predominated in the surgical wound which is in line with the literature reviewed. Half of the studied isolates proved meticillin-resistant S. aureus. All antimicrobials tested except vancomycin, showed higher percentages of meticillin resistance in isolates resistant to meticillin sensitive in which an increase in the hospital stay and cost of care for patients with S. aureus meticillin resistant.

OBJECTIF: le but de ce travail est de caractériser du point de vue microbiologique les isolats de Staphylococcus aureus prélevés des échantillons purulents de patients affectés par des infections associées aux soins de santé du service d'orthopédie de l'hôpital universitaire "Fructuoso Rodríguez" depuis janvier jusqu'à mai 2014. MÉTHODES: une étude descriptive de 134 échantillons de patients hospitalisés à l'hôpital universitaire "Fructuoso Rodríguez" a été réalisée depuis janvier jusqu'à mai 2014. L'analyse de ces échantillons a été effectuée par des méthodes microbiologiques conventionnelles. La susceptibilité antimicrobienne a été définie par la méthode de Kirby Bauer et le test de sensibilité à la vancomycine dans les échantillons où le S. aureus a été récupéré. RÉSULTATS: le S. aureus a été identifié dans 41 % des isolats. Une partie (52.7 %) a été obtenue des blessures chirurgicales. On a trouvé que 50.9 % des isolats de S. aureus étaient résistants à la méticilline, tandis qu'aucune souche résistante à la vancomycine n'a été trouvée. Les isolats de S. aureus résistant à la méticilline étaient significativement plus résistants que les isolats de S. aureus sensibles à la méticilline pour l'érythromycine et les tétracyclines (tétracycline et doxicilline). CONCLUSIONS: le Staphylococcus aureus a été le microorganisme le plus souvent trouvé dans les échantillons purulents étudiés. Concernant les isolats hospitaliers, le S. aureus a été en majorité surtout dans les blessures chirurgicales, ce qui est en correspondance avec la littérature révisée. La moitié des isolats analysés ont mis en évidence un Staphylococcus aureus résistant à la méticilline. Tous les antimicrobiens testés, à l'exception de la vancomycine, ont montré des pourcentages de résistance beaucoup plus hauts dans les isolats résistants à la méticilline que dans les isolats sensibles à la méticilline. Ceci a résulté en une augmentation du séjour hospitalier et du coût des soins de santé des patients touchés par S. aureus résistant à la méticilline.

Perfil de sensibilidade aos antimicrobianos e eficácia de sanitizantes frente aos isolados de Salmonella spp: oriundos de carcaças suínas no Rio Grande do Sul / Antimicrobial sensitivity and efficacy of sanitizers against the Salmonella spp: isolated from swine slaughterhouse in southern Brazil

Os objetivos do trabalho foram avaliar o perfil de sensibilidade a antimicrobianos e a eficácia de três sanitizantes frente a isolados de Salmonella spp. oriundos de carcaças na tecnologia de abate de suínos. Avaliaram-se 120 amostras, das quais 39 foram positivas para Salmonella spp. Os princípios ativos testados foram penicilina G 10 U, amoxicilina + ácido clavulânico 30mcg, ampicilina 10mcg, cloranfenicol 30mcg, tetraciclina 30mcg, estreptomicina 10mcg, neomicina 30mcg, gentamicina 10mcg, enrofloxacina 5mcg, sulfazotrim 25mcg, sulfonamida 300mcg e trimetropima 5mcg. Nos testes com sanitizantes utilizaram-se clorexidina, amônia quaternária e ácido peracético com tempos de contato de um, cinco, 10 e 15 minutos. Os índices de resistência aos antimicrobianos foram de 100 por cento para penicilina, 94,9 por cento para tetraciclina, 89,7 por cento para trimetropima e 87,2 por cento para ampicilina. Nenhum dos princípios ativos foi 100 por cento eficaz frente aos isolados testados, observando-se melhor ação para amoxicilina+ácido clavulânico (86,7 por cento), neomicina (86,7 por cento) e cloranfenicol (64,1 por cento). Nos testes de eficácia dos sanitizantes, o ácido peracético a 0.5 por cento foi efetivo a partir de 10 minutos (94,6 por cento) e 15 minutos (97,3 por cento) de contato; amônia quaternária a 1 por cento por 10 minutos (89,2 por cento) e 15 minutos (97,3 por cento) e clorexidina a 0.5 por cento por 10 minutos (70,3 por cento) e 15 minutos de contato (72,8 por cento). Todas as amostras testadas apresentaram multirresistência e seis [...] O sanitizante mais efetivo frente aos isolados testados foi o ácido peracético a 0.5 por cento por 15 minutos, reforçando a necessidade de monitorar também a efetividade de produtos sanitizantes frente aos isolados de Salmonella spp.

The aim of this study was to evaluate the antimicrobial sensitivity and efficacy of three sanitizers against Salmonella spp. isolated from carcasses in swine slaughterhouse. Thirty nine of 120 samples were positive for Salmonella spp. The antimicrobials tested included: penicillin G 10 U, amoxicillin + clavulanic acid 30mcg, ampicillin 10mcg, chloramphenicol 30mcg, tetracycline 30mcg, streptomycin 10mcg, gentamicin 10mcg, neomycin 30mcg, enrofloxacin 5mcg, sulfazotrim 25mcg, sulfonamide 300mcg and trimetropim 5mcg. In the tests with sanitizers were used chlorhexidine, quaternary ammonia and peracetic acid, which were put in contact intervals of 1, 5, 10 and 15 minutes. Antimicrobial resistance was observed using penicillin (100 percent), tetracycline (94.9 percent), trimetropim (89.7 percent), and ampicillin (87.2 percent). None of the antimicrobials was 100 percent effective against the samples tested. Amoxicillin + clavulanic acid (86.7 percent), neomycin (86.7 percent) and chloramphenicol (64.1 percent) showed better antimicrobial action. In tests of efficacy of sanitizers, 0.5 percent peracetic acid was effective at 10 minutes (94.6 percent) and 15 minutes (97.3 percent) of contact; 1 percent quaternary ammonia at 10 minutes (89.2 percent) and 15 minutes (97.3 percent) and 0.5 percent chlorhexidine at 10 minutes (70.3 percent) and 15 minutes (72.8 percent). All samples tested were multidrug resistance and six (15.3 percent) showed resistance to ampicillin, chloramphenicol, streptomycin, sulfonamide and tetracycline (ACSSuT group) indicating the need to monitor the spread of antimicrobial resistance of Salmonella spp. isolated from swine. The most effective sanitizing against the bacteria tested was 0.5 percent peracetic acid per 15 minutes, reinforcing the need to monitor the effectiveness of products sanitizers against Salmonella spp.

Infecções do trato urinário (ITU) de cães e gatos: etiologia e resistência aos antimicrobianos / Urinary tract infection (UTI) in dogs and cats: etiology and antimicrobial resistance

As infecções bacterianas do trato urinário (ITUs) são causa comum de doença em cães, gatos e humanos. Embora bactérias Gram positivas como Staphylococcus spp., Streptococcus spp. e Enterococcus spp., possam ocasionar ITUs, as bactérias Gram negativas (Escherichia coli, Proteus spp., Klebsiella spp., Pseudomonas spp. e Enterobacter spp.) respondem por 75% dos casos. Este estudo teve como objetivo determinar a frequência de diferentes gêneros de bactérias em ITUs em cães e gatos, bem como a sua sensibilidade aos antimicrobianos utilizados na rotina clínica. Portanto, amostras de urina de 100 cães e gatos com sinais de ITU foram coletadas assepticamente, sofrendo avaliação microbiológica por meio de métodos qualitativos e quantitativos, além de urinálise. Todos os isolados foram submetidos a testes de sensibilidade aos antimicrobianos. ITU foi confirmada em 74% dos animais, não havendo predominância quanto ao sexo. No que diz respeito à idade, 85% dos cães e 87% dos gatos tinham idades superiores a seis anos. Noventa e cinco cepas bacterianas foram isoladas, com maior frequência de Escherichia coli (55% do total) dos sorogrupos O6 e O2. Constatou-se níveis elevados de resistência a antimicrobianos nas cepas isoladas. Para as cepas Gram positivas, tetraciclina (46,1%), enrofloxacina, cotrimazol e estreptomicina (42,3% cada) foram as drogas com os maiores índices de resistência. Para as Gram negativas, amoxacilina e tetraciclina apresentaram percentuais acima de 50%. Multiresistência foi verificada em mais de 50% dos principais gêneros isolados. Considerando-se que as cepas de E. coli apresentam potencial zoonótico e forte participação na disseminação de resistência aos antimicrobianos, ressalta-se a importância do papel do médico veterinário na prevenção e controle das ITUs animais e sua contribuição para a saúde pública.

Bacterial urinary tract infections (UTIs) are a common cause of disease in dogs, cats and humans. Although Gram-positive bacteria such as Staphylococcus spp., Streptococcus spp. and Enterococcus spp. are linked with UTIs, Gram-negative bacteria (Escherichia coli, Proteus spp., Klebsiella spp., Pseudomonas spp. and Enterobacter spp.) account for 75% of the cases. This study aimed to determine the frequency of different genera of bacteria in UTIs of dogs and cats as well as their susceptibility to antimicrobials used in clinical routine. Therefore, urine samples from 100 dogs and cats suspected of UTI were collected aseptically. Samples underwent to microbiological evaluation through qualitative and quantitative methods, and urinalysis. All isolates were tested for antimicrobial susceptibility. UTI was confirmed in 74% of animals, with no predominance in one gender. With regard to age, 85% of dogs and 87% of cats were older than six years. Ninety-five bacterial strains were isolated with higher frequency of Escherichia coli (55% of total) of serogroups O6 and O2. High levels of antimicrobial resistance were found. Gram-positive strains had the highest resistance to tetracycline (46.1%), enrofloxacin, cotrimazol and streptomycin (42.3% each), while above 50% of Gram-negative were resistant to amoxicillin and tetracycline. Multidrug resistance has been observed in more than 50% of the major genera isolated. Considering the zoonotic potential of E. coli strains and its strong participation in antimicrobial resistance dissemination, the important role of the veterinarians in the prevention and control of animal UTIs and their contribution to public health must be emphasized.

Incidence of Tetracycline Resistance Genes, tet(M) and tet(O), in Streptococci Isolated from Dental Plaques of Koreans

Streptococci are among the normal human microflora that populate the oral cavity. However, oral streptococci are known as a major causative agent for dental caries and bacterial endocarditis. Tetracycline is a broad-spectrum antibiotic that is used for oral infections but two mechanisms of tetracycline resistance in streptococci have been reported. The tet(K) and tet(L) genes in these bacteria are related to the active efflux of tetracycline, whereas tet(M) and tet(O) confer ribosomal protection from this antibiotic. It has been reported that the tetracycline resistance of streptococci is related mainly to the activity of tet(M) and tet(O). In our present study, we examined the prevalence of tet(M) and tet(O) in oral streptococci isolated from Korean dental plaques using PCR. One hundred and forty eight of 635 isolates (23.3%) were tetracycline resistant; 68 of these strains (46%) harbored tet(M) and 3 strains (2%) were positive for tet(O). However, tet(M) and tet(O) did not co-exist in any of the resistant strains. Seventy seven of the 148 tetracycline resistant strains (52%) were negative for both the tet(M) and tet(O) genes.

Epidemiological characteristics of Salmonella in animal source foods in Hunan / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the molecular epidemiological characteristics of Salmonella in animal source foods in Hunan.</p><p><b>METHODS</b>The fair trade markets and supermarkets of ten cities were chosen to sample animal source foods for isolating Salmonella in Hunan province in 2010. A total of 692 samples were collected by aseptic sampling, included 159 livestock meats, 152 poultry meats, and 381 aquatic products.Salmonella strains isolated were subjected to stereotyping, antimicrobial susceptibility testing and pulsed field gel electrophoresis (PFGE).</p><p><b>RESULTS</b>Salmonella was detected in 93 of 692 animal food samples with the detection rate of 13.4%. The detection rates of Salmonella in poultry meats, livestock meats and aquatic products were 23.0% (35/152), 22.6% (36/159) and 5.8% (22/381) respectively. Therefore, the detection rate in aquatic products was lower than that of poultry meats and livestock meats (χ(2) = 33.86, P < 0.05; χ(2) = 33.29, P < 0.05, respectively). The serotypes of isolates showed diversity, and Salmonella Derby (33/94, 35.1%) was the predominant serotypes.79.8% (75/94) strains showed resistant to more than one antibiotic used in the test, 31.9% (30/94) strains showed resistant to more than 5 antibiotics. A significant difference was observed for multidrug resistance between Salmonella isolated from poultry (47.2%, 17/36) and livestock meats (22.2%, 8/36) (χ(2) = 4.96, P < 0.05). And the highest resistant rate was found in tetracycline, as high as 62.8% (59/94). All the strains were divided into 69 PFGE subtypes.Furthermore the dominating subtypes were type 7 (6 strains), type 15 (4 strains), type 22 (6 strains).</p><p><b>CONCLUSION</b>Inspection results showed that Salmonella contamination in animal source foods were serious in Hunan province, and the isolates expressed high level resistance to the antibiotics.Furthermore the PFGE results indicated that there were epidemic strains of Salmonella in Hunan.</p>

Stress tolerant virulent strains of Cronobacter sakazakii from food

BACKGROUND: Cronobacter sakazakii is considered as an emerging foodborne pathogen. The aim of this study was to isolate and characterize virulent strains of Cronobacter sakazakii from food samples of Bangladesh. RESULT: Six (6) Cronobacter sakazakii was isolated and identified from 54 food samples on the basis of biochemical characteristics, sugar fermentation, SDS-PAGE of whole cell protein, plasmid profile and PCR of Cronobacter spp. specific genes (esak, gluA, zpx, ompA, ERIC, BOX-AIR) and sequencing. These strains were found to have moderately high antibiotic resistance against common antibiotics and some are ESBL producer. Most of the C. sakazakii isolates were capable of producing biofilm (strong biofilm producer), extracellular protease and siderophores, curli expression, haemolysin, haemagglutinin, mannose resistant haemagglutinin, had high cell surface hydrophobicity, significant resistance to human serum, can tolerate high concentration of salt, bile and DNase production. Most of them produced enterotoxins of different molecular weight. The isolates pose significant serological cross-reactivity with other gram negative pathogens such as serotypes of Salmonella spp., Shigella boydii, Shigella sonnei, Shigella flexneri and Vibrio cholerae. They had significant tolerance to high temperature, low pH, dryness and osmotic stress. CONCLUSION: Special attention should be given in ensuring hygiene in production and post-processing to prevent contamination of food with such stress-tolerant virulent Cronobacter sakazakii.

Antimicrobial resistance in neisseria gonorrhoeae isolates from ribeirão preto, São Paulo, Brazil

Gonorrhea is sexually transmitted, with a high incidence worldwide. Occurrence of resistance and difficulties in treatment is often reported. Penicillin is not used anymore, and quinolones or cephalosporins are the remaining therapeutic options. However, there are resistance reports to these drugs as well. Objective: to evaluate the occurrence of resistance to penicillin, tetracycline, ofloxacin, ciprofloxacin, azithromycin and ceftriaxone in Neisseria gonorrhoeae (gonococcus). Methods: ninety-three endocervical and urethral secretion samples, suspected of gonorrhea, were cultured from September 2008 to May 2012. Samples were collected at the STD/Aids Reference Center and processed at Instituto Adolfo Lutz in Ribeirão Preto, SP, Brazil. Antimicrobial susceptibility tests were performed by the E-test (Oxoid). Beta-lactamase was determined by the cefinase disk method (BD BBL). The susceptibility study included a gonococcus isolated from a case of conjunctivitis. Results: gonococcus was isolated in 41.9% (35) of the cases in the study. Male patients were predominant in 92.3% of samples, with ages ranging from 14 to 62 years, and the conjunctivitis isolate was recuperated from a 1 month old patient. Isolates were resistant to penicillin (44.4%); tetracycline (55.5%); ofloxacin (36.1%) and ciprofloxacin (36.1%). All isolates were susceptible to ceftriaxone, and 80.6% were susceptible to azithromycin. The beta-lactamase test was positive for 31.0% of isolates. Conclusion: in vitro results showed that tetracycline was less effective, and ceftriaxone the most effective antibiotic against gonococcus. The resistance to different drugs limits the options of gonococcus effective treatment.

Resistência antimicrobiana em Enterococcus faecalis e Enterococcus faecium isolados de carcaças de frango / Antimicrobial Resistance of Enterococcus faecalis and Enterococcus faecium isolated from poultry carcasses

O objetivo deste trabalho foi realizar o isolamento e analisar o perfil de resistência antimicrobiana de Enterococcus de carcaças de frango resfriadas e congeladas comercializadas no Distrito Federal, detectando genes de resistência antimicrobiana e identificando as espécies Enterococcus faecalis e Enterococcus faecium por reação polimerase em cadeia. Foram analisadas 100 carcaças de frangos, das quais foram isoladas 50 cepas de Enterococcus spp., sendo 42% de E. faecalis e 2% de E. faecium. O teste de susceptibilidade antimicrobiana demonstrou que todas as cepas isoladas apresentaram resistência a pelo menos um antimicrobiano, dos quais 90,47% das cepas de E. faecalis, 100% das cepas de E. Faecium e 82,14% dos Enterococcus spp. apresentaram resistência à Tetraciclina; 80,95% das cepas de E. faecalis e 35,71% das cepas de Enterococcus spp. foram resistentes à Eritromicina; 39,28% dos Enterococcus spp. e 23,80% dos E. faecalis à Ciprofloxacina e 28,57% dos E. faecalis apresentaram resistência ao Cloranfenicol. Foram detectados os genes de resistência antimicrobiana erm(B), vanC-1, aph(3')-llla, ant(6)-la, vanB, vanA, aac(6')-le-aph(2'')-la, erm(A) e tet(M) - este último mais frequente. Estes resultados sugerem sérios problemas para a Saúde Pública, uma vez que esses microrganismos podem possuir a capacidade de transmitir genes de resistência antimicrobiana para outros microrganismos presentes na microbiota intestinal de humanos e animais, podendo inviabilizar o uso destas drogas para tratamentos clínicos.

The aim of this study was to isolate and analyze the antimicrobial profile resistance of Enterococcus from cooled and frozen poultry carcasses commercialized at the Federal District area, detecting the antimicrobial resistance genes and identifying Enterococcus faecalis and Enterococcus faecium by polymerase chain reaction. One hundred poultry carcasses were analyzed and 50 strains of Enterococcus spp. were isolated, of which 42% were E. faecalis and 2% E. faecium. The antimicrobial susceptibility test showed that all isolates were resistant to at least one antibiotic; 90,47% of E. faecalis, 100% of E. faecium and 82,14% of Enterococcus spp. were resistant to Tetracycline; 80,95% of E. faecalis and 35,71% of Enterococcus spp. strains were resistant to Erythromycin; 39,28% of Enterococcus spp. and 23,80% of E. faecalis to Ciprofloxacin, and 28,57% of E. faecalis were resistant to Chloramphenicol. There were detected erm(B), vanC-1, aph(3')-llla, ant(6)-la, vanB, vanA, aac(6')-le-aph(2'')-la, erm(A) and tet(M) resistance genes, the last one most often verified. The results might suggest problems for public health due the high resistance, since these microorganisms have ability to transmit genes for antimicrobial resistance to others in the intestinal tract of humans and animals. Thus, the use of these drugs for clinical treatment could be hindered.

Antimicrobial susceptibility of Clostridium perfringens isolated from piglets with or without diarrhea in Brazil

The minimum inhibitory concentration (MIC) was determined for 13 antibiotics against Clostridium perfringens isolated from Brazilian piglets. The collection of isolates was performed in June to October 2010. All isolates were susceptible to amoxicillin and ceftiofur, whereas most were resistant to tetracycline and lincomycin. Avilamycin and narasin were more effective against isolates from non-diarrheic than from diarrheic piglets. The other antimicrobials were less active in need of high concentrations to inhibit the growth of the C. perfringens type A. These results suggest the need for further studies evaluating molecular factors related to the antimicrobial resistance of C. perfringens.

Estado actual de la resistencia de Helicobacter pylori a tetraciclina:revisión sistemática de la literatura / Current status of Helicobacter pylori resistance to tetracycline: a systematic review of the literature / Estado atual da resistência do Helicobacter pylori à tetraciclina: uma revisão sistemática da literatura

Determinar la prevalencia de resistencia de Helicobacter pylori a tetraciclina y las posibles mutaciones que generan estaresistencia mundialmente. Materiales y método. Se realizó una búsqueda sistemática de literatura en las bases de datos: Medline,Science Direct (Elsevier), Ovid, Pubmed, Lilacs y MEDICLATINA, con el uso de palabras clave relevantes. La extracción de losdatos fue independiente y se realizaron listas de verificación para evaluar la calidad metodológica de los estudios. El análisis de lainformación fue realizado en el programa RevMan 5®. Resultados. Se evidenció resistencia a tetraciclina por Helicobacter pyloricon prevalencias de 1% para Norte América, 8% para Centro y Sur América; 5% para Asia y 2% para Europa . La alta resistencia sedebe a la triple mutación AGA(926-928)-->TTC, en el gen 16S rDNA. Conclusiones. La resistencia antibiótica es una de las causasque más se asocia a falla terapéutica en la erradicación de Helicobacter pylori, así como la poca adherencia al tratamiento y el usoindiscriminado de antibióticos. Se evidenció que la tasa de resistencia a tetraciclina aumenta después de un primer tratamiento con esteantibiótico, sin embargo la prevalencia de la resistencia global a tetraciclina es baja sin aún alcanzar límites que impidan su utilizaciónen los esquemas de tratamiento...

To determinethe prevalence of Helicobacter pylori resistance to and the possible mutations that generate this worldwide resistance. Materials andmethods. A systematic search for literature was performed in the databases Medline, Science Direct (Elsevier), Ovid, PubMed, Lilacsand MedicLatina using relevant key words. Data extraction was independent and checklists were prepared to assess the methodologicalquality of the studies. Analysis of information was done with RevMan 5®. Results. We found Helicobacter pylori resistance prevalencerates of 1% for North America, 8% for Central and South America, 5% for Asia, and 2% for Europe. The mutation associated to thisresistance is in the 16S rDNA gene at nucleotide position 967TTC to AGA965 responsible of high resistance to tetracycline. Conclusions.Antibiotic resistance is one of the causes most associated to treatment failure in the eradication of Helicobacter pylori, as well as pooradherence to treatment and indiscriminate use of antibiotics. We also evidenced that the rate of tetracycline resistance is higher whenit is used in a second treatment scheme. The distribution of resistance is variable in different areas and it is important to know theseresistances to avoid treatment failures...

Determinara prevalência da resistência do Helicobacter pylori à tetraciclina e possíveis mutações que geram esta resistência a nível mundial.Materiais e métodos. Foi realizada uma procura sistemática da literatura nas bases de dados Medline, Science Direct (Elsevier), Ovid,Pubmed, Lilacs e MEDICLATINA, usando palavras-chave relevantes. A extração dos dados foi independente e realizaram-se listas deverificação para avaliar a qualidade metodológica dos estudos. A análise dos dados foi realizada em REVMAN 5®. Resultados. Foievidenciada a resistência de Helicobacter pylori com taxas de prevalência de 1% para a América do Norte, 8% para América Central eAmérica do Sul; 5% para Ásia e 2% para Europa. A mutação associada a estas resistências no gen 16S rDNA nos nucleótidos da posiçãoAGA965 a 967TTC é responsável da alta resistência à tetraciclina. Conclusões. A resistência aos antibióticos é uma das razões maisassociadas à falha do tratamento na erradicação de Helicobacter pylori, assim como a pouca adesão ao tratamento e uso indiscriminadode antibióticos; também foi evidente que a taxa de resistência à tetraciclina é maior quando utilizado em regime de segundo tratamento;a distribuição da resistência varia em diferentes áreas e é importante saber estas resistências a fim de evitar falhas terapêuticas...

Mechanisms of action of systemic antibiotics used in periodontal treatment and mechanisms of bacterial resistance to these drugs

Antibiotics are important adjuncts in the treatment of infectious diseases, including periodontitis. The most severe criticisms to the indiscriminate use of these drugs are their side effects and, especially, the development of bacterial resistance. The knowledge of the biological mechanisms involved with the antibiotic usage would help the medical and dental communities to overcome these two problems. Therefore, the aim of this manuscript was to review the mechanisms of action of the antibiotics most commonly used in the periodontal treatment (i.e. penicillin, tetracycline, macrolide and metronidazole) and the main mechanisms of bacterial resistance to these drugs. Antimicrobial resistance can be classified into three groups: intrinsic, mutational and acquired. Penicillin, tetracycline and erythromycin are broad-spectrum drugs, effective against gram-positive and gram-negative microorganisms. Bacterial resistance to penicillin may occur due to diminished permeability of the bacterial cell to the antibiotic; alteration of the penicillin-binding proteins, or production of β-lactamases. However, a very small proportion of the subgingival microbiota is resistant to penicillins. Bacteria become resistant to tetracyclines or macrolides by limiting their access to the cell, by altering the ribosome in order to prevent effective binding of the drug, or by producing tetracycline/macrolide-inactivating enzymes. Periodontal pathogens may become resistant to these drugs. Finally, metronidazole can be considered a prodrug in the sense that it requires metabolic activation by strict anaerobe microorganisms. Acquired resistance to this drug has rarely been reported. Due to these low rates of resistance and to its high activity against the gram-negative anaerobic bacterial species, metronidazole is a promising drug for treating periodontal infections.

Genetic Classification and Antimicrobial Resistance of Ureaplasma urealyticum Isolated from Urine

Recently, polymerase chain reaction (PCR)-based methods have been used to reclassify Ureaplasma urealyticum into two independent species (spp.), designating U. parvum and U. urealyticum. In the current study, we aim to reclassify U. urealyticum and to analyze the correlation between the presence of a genetic marker and an antibiotic resistance of U. urealyticum. Susceptibility test against tetracycline, levofloxain or moxifloxacin was performed by broth microdilution method. The presence of tet(M) gene and the mutations of quinolone resistance-determining regions (QRDRs) were analyzed by PCR and sequencing. Among fourteen Ureaplasma isolates, three were identified as U. parvum and eleven were identified as U. urealyticum, and this is first report showing that two independent spp. of U. urealyticum isolated from Korean are present. The minimum inhibitory concentration (MIC) ranges for Ureaplasma isolates were as follows: tetracycline 0.25~128 microg/ml, levofloxacin 1~8 microg/ml, and moxifloxacin 0.5~4 microg/ml. The tet(M) determinant was found in 3 among 14 Ureaplasma isolates with tetracycline MIC of >16 microg/ml, suggesting that the presence of the tet(M) determinant is associated with tetracycline resistance. Mutations of gyrA, gyrB, parC, and parE genes in the QRDRs were found in 3 among 14 Ureaplasma isolates, exhibiting only parE gene mutation is associated with fluoroquinolone resistance.

Detection and sequencing of plasmid encoded tetracycline resistance determinants (tetA and tetB) from food-borne Bacillus cereus isolates

OBJECTIVE@#To investigate the detection and sequencing of plasmid encoded tetracycline resistance genes (tetA and tetB) from food-borne and standard strains of Bacillus cereus (B. cereus).@*METHODS@#A PCR was carried out to detect the tetracycline resistance genes (tetA and tetB) in food-borne B. cereus strains and the amplified products were sequenced.@*RESULTS@#The phenotypic resistance against tetracycline was observed in 39 of the 118 food-borne isolates and two reference strains (MTCC 430 and MTCC 1307) of B. cereus. Among the phenotypically resistant isolates, tetA was detected in 36 food-borne isolates and two reference strains (MTCC 430 and MTCC 1307), whereas, tetB was detected in 12 food-borne isolates and MTCC 1307 strain.@*CONCLUSIONS@#A close association was therefore found between phenotypic resistance against tetracycline and presence of tetracycline resistance genes. The tetA and tetB gene fragments were amplified, purified and sequenced. The gene sequences of the isolates studied herein were found similar to tetA and tetB gene sequences of other bacteria available in NCBI. The occurrence of tetA and tetB genes in B. cereus indicate the horizontal transfer of antibiotic resistance determinants from other bacteria into B. cereus. The transfer of these resistant determinants to other potentially pathogenic bacteria may be a matter of great concern.

Prevalência de bacilos Gram-negativos não fermentadores de pacientes internados em Porto Alegre-RS / Prevalence of non-fermenting Gram-negative bacilli among inpatients from Porto Alegre-RS

INTRODUÇÃO: Os bacilos Gram-negativos não fermentadores (BGNNF) são frequentemente associados às infecções hospitalares. Além da alta incidência, esses microrganismos possuem resistência a diversos antimicrobianos. OBJETIVO: Analisar a prevalência e o perfil de resistência de BGNNF. MÉTODOS: Foram analisados 14.971 laudos de pacientes em um hospital privado de Porto Alegre-RS, no período de maio de 2006 a março de 2008, sem distinção de sexo e idade. RESULTADOS E CONCLUSÃO: Foram isoladas 326 amostras de BGNNF. As espécies mais prevalentes foram: Pseudomonas aeruginosa (65,03 por cento), Acinetobacter baumannii (16,56 por cento) e Stenotrophomonas maltophilia (9,5 por cento). Outras espécies apresentaram índices inferiores a 5 por cento. Os microrganismos foram isolados de diversos sítios infecciosos. Os materiais biológicos que apresentaram maior positividade para esses microrganismos foram o aspirado traqueal (38,34 por cento), o escarro (18,71 por cento) e a urina (15,95 por cento). A resistência bacteriana mostrou-se mais expressiva a tetraciclinas (89,57 por cento) e sulfametoxazol/trimetoprima (79,75 por cento). Os antimicrobianos mais ativos foram polimixina B, com 100 por cento de sensibilidade, e piperaciclina/tazobactam, com 75,2 por cento de sensibilidade.

INTRODUCTION: The non-fermenting Gram-negative bacilli (NFGNB) have been widely associated with nosocomial infections. Not only are these microorganisms highly prevalent but they are also highly resistant to NFGNB. OBJECTIVE: To assess the prevalence and resistance profile of non-fermenting Gram-negative bacilli. METHODS: 14.971 patient reports from a private hospital in Porto Alegre, Rio Grande do Sul, from May/2006 to March/2008 were analyzed. RESULTS AND CONCLUSION: Three hundred twenty-six samples of non-fermenting Gram-negative bacilli were isolated. The most prevalent species were Pseudomonas aeruginosa (65.03 percent), Acinetobacter baumannii (16.56 percent), and Stenotrophomonas maltophilia (9.5 percent). Other species showed rates lower than 5 percent. The microorganisms were isolated from several infectious sites and the biological materials that showed higher positivity were the following: tracheal aspirate (38.34 percent), spittle (18.71 percent) and urine (15.95 percent). Bacterial resistance was higher with tetracyclines (89.57 percent) and sulfamethoxazole/trimethoprim (79.75 percent). The most active antimicrobials were polymyxin B and piperacillin/tazobactam with 100 percent and 75.2 percent sensibility, respectively.

Molecular characterization of tetracycline- and quinolone-resistant Aeromonas salmonicida isolated in Korea

The antibiotic resistance of 16 Aeromonas (A.) salmonicida strains isolated from diseased fish and environmental samples in Korea from 2006 to 2009 were investigated in this study. Tetracycline or quinolone resistance was observed in eight and 16 of the isolates, respectively, based on the measured minimal inhibitory concentrations. Among the tetracycline-resistant strains, seven of the isolates harbored tetA gene and one isolate harbored tetE gene. Additionally, quinolone-resistance determining regions (QRDRs) consisting of the gyrA and parC genes were amplified and sequenced. Among the quinolone-resistant A. salmonicida strains, 15 harbored point mutations in the gyrA codon 83 which were responsible for the corresponding amino acid substitutions of Ser83-->Arg83 or Ser83-->Asn83. We detected no point mutations in other QRDRs, such as gyrA codons 87 and 92, and parC codons 80 and 84. Genetic similarity was assessed via pulsed-field gel electrophoresis, and the results indicated high clonality among the Korean antibiotic-resistant strains of A. salmonicida.