Antimicrobial resistance of Enterobacteriaceae and Staphylococcus spp. isolated from raw cow's milk from healthy, clinical and subclinical mastitis udders.

Mastitis is the most common disease of dairy cattle and can be manifested in clinical and subclinical forms. The overuse of antimicrobials in the treatment and prevention of mastitis favours antimicrobial resistance and milk can be a potential route of dissemination. This study aimed to evaluate the biological quality of bulk tank milk (BTM) and the microbiological quality and signs of mastitis of freshly milked raw milk. In addition, to evaluate antimicrobial resistance in Enterobacteriaceae and Staphylococcus spp. isolated from freshly milked raw milk. None of the farms were within the official Brazilian biological quality limits for BTM. Freshly milked raw milk with signs of clinical (CMM), subclinical (SCMM) and no signs (MFM) of mastitis were detected in 6.67%, 27.62% and 65.71% samples, respectively. Most samples of freshly milked raw milk showed acceptable microbiological quality, when evaluating the indicators total coliforms (78.10%), Escherichia coli (88.57%) and Staphylococcus aureus (100%). Klebsiella oxytoca and S. aureus were the most prevalent microorganisms in SCMM and MFM samples. Antimicrobial resistance and multidrug resistance (MDR) were observed in 65.12% and 13.95% of Enterobacteriaceae and 84.31% and 5.88% of Staphylococcus spp., respectively, isolated from both SCMM and MFM samples. Enterobacteriaceae resistant to third-generation cephalosporin (3GCR) (6.98%) and carbapenems (CRE) (6.98%) and methicillin-resistant S. aureus (MRSA) (4.88%) were observed. Antimicrobial-resistant bacteria can spread resistance genes to previously susceptible bacteria. This is a problem that affects animal, human and environmental health and should be evaluated within the one-health concept.

Genomic epidemiology of third-generation cephalosporin-resistant Escherichia coli from Argentinian pig and dairy farms reveals animal-specific patterns of co-resistance and resistance mechanisms.

Control measures are being introduced globally to reduce the prevalence of antibiotic resistance (ABR) in bacteria on farms. However, little is known about the current prevalence and molecular ecology of ABR in bacterial species with the potential to be key opportunistic human pathogens, such as Escherichia coli, on South American farms. Working with 30 dairy cattle farms and 40 pig farms across two provinces in central-eastern Argentina, we report a comprehensive genomic analysis of third-generation cephalosporin-resistant (3GC-R) E. coli, which were recovered from 34.8% (cattle) and 47.8% (pigs) of samples from fecally contaminated sites. Phylogenetic analysis revealed substantial diversity suggestive of long-term horizontal and vertical transmission of 3GC-R mechanisms. CTX-M-15 and CTX-M-2 were more often produced by isolates from dairy farms, while CTX-M-8 and CMY-2 and co-carriage of amoxicillin/clavulanate resistance and florfenicol resistance were more common in isolates from pig farms. This suggests different selective pressures for antibiotic use in these two animal types. We identified the ß-lactamase gene blaROB, which has previously only been reported in the family Pasteurellaceae, in 3GC-R E. coli. blaROB was found alongside a novel florfenicol resistance gene, ydhC, also mobilized from a pig pathogen as part of a new composite transposon. As the first comprehensive genomic survey of 3GC-R E. coli in Argentina, these data set a baseline from which to measure the effects of interventions aimed at reducing on-farm ABR and provide an opportunity to investigate the zoonotic transmission of resistant bacteria in this region. IMPORTANCE: Little is known about the ecology of critically important antibiotic resistance among bacteria with the potential to be opportunistic human pathogens (e.g., Escherichia coli) on South American farms. By studying 70 pig and dairy cattle farms in central-eastern Argentina, we identified that third-generation cephalosporin resistance (3GC-R) in E. coli was mediated by mechanisms seen more often in certain species and that 3GC-R pig E. coli were more likely to be co-resistant to florfenicol and amoxicillin/clavulanate. This suggests that on-farm antibiotic usage is key to selecting the types of E. coli present on these farms. 3GC-R E. coli and 3GC-R plasmids were diverse, suggestive of long-term circulation in this region. We identified the de novo mobilization of the resistance gene blaROB from pig pathogens into E. coli on a novel mobile genetic element, which shows the importance of surveying poorly studied regions for antibiotic resistance that might impact human health.

Molecular characterization of Escherichia coli producing extended-spectrum ß-lactamase CTX-M-14 and CTX-M-28 in Mexico.

The spread of ESBL-producing Escherichia coli has constantly increased in both clinical and community infections. Actually, the main ESBL reported is the CTX-M family, which is widely disseminated between the Enterobacteriaceae family. The epidemiology of the CTX-M family shows the CTX-M-15 variant dominating worldwide, followed by CTX-M-14 and CTX-M-27. The specific ESBL-producing E. coli clones included mainly the sequence types ST131, ST405, and ST648. In this report, we present the molecular characterization of ESBL-producing E. coli clinical isolates from eight hospitals in Mexico. From a collection of 66 isolates, 39 (59%) were identified as blaCTX-M-14 and blaCTX-M-27 belonging to the group CTX-M-9. We identified 25 (38%) isolates, producing blaCTX-M-28 belonging to the group CTX-M-1. blaCTX-M-2 and blaTEM-55 were identified in one isolate, respectively. Fourteen isolates (21%) were positive for blaCTX-M-14 (13%) and blaCTX-M-28 (7.3%) that were selected for further analyses; the antimicrobial susceptibility showed resistance to ampicillin (> 256 µg/mL), cefotaxime (> 256 µg/mL), cefepime (> 64 µg/mL), and ceftazidime (16 µg/mL). The ResFinder analysis showed the presence of the antimicrobial resistance genes aacA4, aadA5, aac(3)lla, sul1, dfrA17, tet(A), cmlA1, and blaTEM-1B. PlasmidFinder analysis identified in all the isolates the replicons IncFIB, which were confirmed by PCR replicon typing. The MLST analysis identified isolates belonging to ST131, ST167, ST405, and ST648. The ISEcp1B genetic element was found at 250 pb upstream of blaCTX-M-14 and flanked by the IS903 genetic element at 35 pb downstream. The IS1380-like element ISEc9 family transposase was identified at 250 pb upstream of blaCTX-M-14 and flanked downstream by the IS5/IS1182 at 80 pb. Our study highlights the significant prevalence of CTX-M-14 and CTX-M-28 enzymes as the second-most common ESBL-producing E. coli among isolates in Mexican hospitals. The identification of specific sequence types in different regions provides valuable insights into the correlation between ESBL and E. coli strains. This contribution to understanding their epidemiology and potential transmission routes is crucial for developing effective strategies to mitigate the spread of ESBL-producing E. coli in healthcare settings.

Genome sequence of an Acinetobacter pittii strain obtained from a red-lored parrot with pneumonia.

Acinetobacter pittii 978-A_19 was obtained from a parrot with pneumonia. It is resistant to ampicillin, carbenicillin, cephalosporins, clindamycin, and trimethoprim + sulfamethoxazole. The genome encodes a new blaADC allele, a blaOXA-502 gene, possesses several virulence genes related to adherence and biofilm formation, and has types I, II, and IV secretion systems.

Distribution of blaCTX-M-gene variants in E. coli from different origins in Ecuador.

The increasing abundance of extended spectrum (ß-lactamase (ESBL) genes in E. coli, and other commensal and pathogenic bacteria, endangers the utility of third or more recent generation cephalosporins, which are major tools for fighting deadly infections. The role of domestic animals in the transmission of ESBL carrying bacteria has been recognized, especially in low- and middle-income countries, however the horizontal gene transfer of these genes is difficult to assess. Here we investigate blaCTX-M gene diversity (and flanking nucleotide sequences) in E. coli from chicken and humans, in an Ecuadorian rural community and from chickens in another location in Ecuador. The blaCTX-M associated sequences in isolates from humans and chickens in the same remote community showed greater similarity than those found in E. coli in a chicken industrial operation 200 km away. Our study may provide evidence of blaCTX-M transfer between chickens and humans in the community.

Characterization of third generation cephalosporin-resistant Escherichia coli clinical isolates from Ushuaia, Argentina / Caracterización de aislamientos clínicos de Escherichia coli resistente a cefalosporinas de tercera generación de Ushuaia, Argentina

Abstract Escherichia coli is one of the main human pathogens causing different hospital- and community-acquired infections. During the period from January 2013 to March 2015, 1.96% (32/1632) of E. coli isolates recovered at the Hospital Regional de Ushuaia, Tierra del Fuego province, were resistant to third-generation cephalosporins (TGCs). These isolates were resistant to cefotaxime (91%) and/or ceftazidime (28%). No resistance to carbapenems was detected. Twenty-six isolates were positive for blaCTX-M gene, grouped as CTX-M-1/15 (54%); CTX-M-9/14 (25%); CTX-M-2 (17%); and CTX-M-1/15 plus CTX-M-9/14 (4%). Five TGC-resistant strains were positive for blaCMY gene, while one strain harbored TEM-19 ESBL. Twelve isolates were identified as ST131 E. coli hyperepidemic clone, and one as ST69. Genome sequence analysis of seven blaCTX-M-15 E. coli selected isolates confirm the circulation of ST131, ST617 and ST405 international high-risk clones in the city of Ushuaia.

Resumen Escherichia coli es uno de los principales patógenos humanos causantes de diferentes infecciones de inicio hospitalario y comunitario. Se determinó que el 1,96% (32/1.632) de los aislamientos de E. coli recuperados entre enero de 2013 y marzo de 2015 en el Hospital Regional de Ushuaia, provincia de Tierra del Fuego, fueron resistentes a cefalosporinas de tercera generación (CTG). Estos aislamientos fueron resistentes a cefotaxima (91%) y/o a ceftazidima (28%). No se detectó resistencia a los carbapenemes. Veintiséis aislamientos fueron positivos para el gen blaCTX-M, agrupados como CTX-M-1/15 (54%), CTX-M-9/14 (25%), CTX-M-2 (17%) y CTX-M-1/15 más CTX-M-9/14 (4%). Cinco cepas resistentes a CTG dieron positivo para el gen blaCMY, mientras que un aislamiento presentó la BLEE TEM-19. Doce aislamientos se identificaron como clon hiperepidémico E. coli ST131 y uno como ST69. El análisis de las secuencias del genoma de siete aislamientos seleccionados de E. coli blaCTX-M-15 confirmó la circulación de los clones internacionales de alto riesgo ST131, ST617 y ST405 en la ciudad de Ushuaia.

Characterization of third generation cephalosporin-resistant Escherichia coli clinical isolates from Ushuaia, Argentina.

Escherichia coli is one of the main human pathogens causing different hospital- and community-acquired infections. During the period from January 2013 to March 2015, 1.96% (32/1632) of E. coli isolates recovered at the Hospital Regional de Ushuaia, Tierra del Fuego province, were resistant to third-generation cephalosporins (TGCs). These isolates were resistant to cefotaxime (91%) and/or ceftazidime (28%). No resistance to carbapenems was detected. Twenty-six isolates were positive for blaCTX-M gene, grouped as CTX-M-1/15 (54%); CTX-M-9/14 (25%); CTX-M-2 (17%); and CTX-M-1/15 plus CTX-M-9/14 (4%). Five TGC-resistant strains were positive for blaCMY gene, while one strain harbored TEM-19 ESBL. Twelve isolates were identified as ST131 E. coli hyperepidemic clone, and one as ST69. Genome sequence analysis of seven blaCTX-M-15E. coli selected isolates confirm the circulation of ST131, ST617 and ST405 international high-risk clones in the city of Ushuaia.

Pharmaceutical nanotechnology: Antimicrobial peptides as potential new drugs against WHO list of critical, high, and medium priority bacteria.

Nanobiotechnology is a relatively unexplored area that has, nevertheless, shown relevant results in the fight against some diseases. Antimicrobial peptides (AMPs) are biomacromolecules with potential activity against multi/extensively drug-resistant bacteria, with a lower risk of generating bacterial resistance. They can be considered an excellent biotechnological alternative to conventional drugs. However, the application of several AMPs to biological systems is hampered by their poor stability and lifetime, inactivating them completely. Therefore, nanotechnology plays an important role in the development of new AMP-based drugs, protecting and carrying the bioactive to the target. This is the first review article on the different reported nanosystems using AMPs against bacteria listed on the WHO priority list. The current shortage of information implies a nanobiotechnological potential to obtain new drugs or repurpose drugs based on the AMP-drug synergistic effect.

Antibiotic resistance profile in intrahospital pediatric services at third level centers in Dominican Republic / Perfil de resistencia a antibióticos en servicios pediátricos intrahospitalarios en centros de tercer nivel en República Dominicana

Objectives: The Dominican Republic lacks reliable information on antimicrobial resistance (AMR), which would allow physicians to prescribe the best treatment for common infectious diseases. This study aimed to define the antimicrobial resistance profiles of the more common pathogens from pediatric services, where data is even more important due to the vulnerability of the population. Methods: We collected data from patients admitted in the pediatric unit of three third level hospitals in the city of Santiago de los Caballeros, Dominican Republic, showing positive bacterial cultures, during a period of two years. Results: Half of the Gram negative pathogens exhibited third generation cephalosporins (3GC) resistance, 17% were resistant to carbapenems. Serratia marcescens presented an exceptionally high proportion of resistance to 3GC (95.9%). Staphylococcus aureus showed elevated resistance to methicillin (58.4%) and even to clindamycin (35.8%). Conclusion: There are elevated levels of antimicrobial resistance among the Enterobacteriaceae family and the Staphylococcus genus isolated from the pediatric population. Necessary measures should be taken to tackle AMR in the country.

Objetivos: La República Dominicana carece de información confiable sobre las resistencias antimicrobianas en el país, lo que permitiría al personal médico prescribir los mejores tratamientos para infecciones comunes. El objetivo de este estudio es definir los perfiles de resistencia antimicrobiana de los patógenos más comunes en servicios pediátricos, donde esta información es esencial, debido a la vulnerabilidad de la población. Métodos: Se tomaron los datos de reportes microbiológicos con cultivo bacteriano positivo procedentes de pacientes admitidos en la unidad pediátrica de tres hospitales de tercer nivel en la ciudad de Santiago de los Caballeros, República Dominicana, durante un periodo de dos años. Resultados: La mitad de los patógenos Gram negativos mostraron resistencia a cefalosporinas de tercera generación (3GC), 17% eran resistentes a carbapenémicos. Serratia marcescens presentó una resistencia excepcionalmente elevada a 3GC (95.9%). Staphylococcus aureus mostró alta resistencia a meticilina (58.4%) e incluso a clindamicina (35.8%). Conclusión: Existen elevados niveles de resistencia antimicrobiana entre las enterobacterias y los estafilococos en la población pediátrica dominicana. Es necesario tomar medidas para abordar este problema en el país.

Penicillin and cephalosporin biosyntheses are also regulated by reactive oxygen species.

In an earlier work on lovastatin production by Aspergillus terreus, we found that reactive oxygen species (ROS) concentration increased to high levels precisely at the start of the production phase (idiophase) and that these levels were sustained during all idiophase. Moreover, it was shown that ROS regulate lovastatin biosynthesis. ROS regulation has also been reported for aflatoxins. It has been suggested that, due to their antioxidant activity, aflatoxins are regulated and synthesized like a second line of defense against oxidative stress. To study the possible ROS regulation of other industrially important secondary metabolites, we analyzed the relationship between ROS and penicillin biosynthesis by Penicillium chrysogenum and cephalosporin biosynthesis by Acremonium chrysogenum. Results revealed a similar ROS accumulation in idiophase in penicillin and cephalosporin fermentations. Moreover, when intracellular ROS concentrations were decreased by the addition of antioxidants to the cultures, penicillin and cephalosporin production were drastically reduced. When intracellular ROS were increased by the addition of exogenous ROS (H2O2) to the cultures, proportional increments in penicillin and cephalosporin biosyntheses were obtained. It was also shown that lovastatin, penicillin, and cephalosporin are not antioxidants. Taken together, our results provide evidence that ROS regulation is a general mechanism controlling secondary metabolism in fungi.

Stability of Ceftazidime Pentahydrate Investigated by Thermal Analysis Techniques.

Cephalosporins are among the most frequently used broad-spectrum antimicrobial agents. Ceftazidime is a semisynthetic ß-lactam antibiotic for parenteral administration widely used in the clinical practice, which has been categorized as a third-generation cephalosporin antibiotic. This drug crystallizes as a pentahydrate and, as all cephalosporins, it is unstable and subject to hydrolytic degradation. Taking this into account, this study investigates the stability under 2 different conditions (high temperature and exposition to vacuum) by using various techniques, as thermal analysis, Raman spectroscopy, and X-ray powder diffraction supported by multivariate curve resolution. It was proved that ceftazidime pentahydrate is unstable under the studied variables, exhibiting several transformation processes, which were discussed in terms of the crystalline structure.

High Levels of Resistance to Cephalosporins Associated with the Presence of Extended-Spectrum and AmpC ß-Lactamases in Escherichia coli from Broilers in Southern Brazil.

The clinical importance of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli has increased steadily over the years. The presence of the blaTEM, blaSHV, and blaCTX-M genes in the environment has been recently recognized as an important issue in the dissemination of resistance to cephalosporins. Food animals are considered important vectors for transfer of ESBL genes from the environment to humans. The objective of this study was to characterize the ESBL genes (blaTEM, blaSHV, and blaCTX-M types) that were most prevalent among 343 ceftazidime-resistant E. coli isolates (17 batches from 12 different farms) obtained from cloacal swabs of broiler chicken in southern Brazil. The blaSHV, blaCTX-M, blaTEM, blaIMP-type, blaVIM-type, blaNDM-1, blaKPC-type, blaGES-type, blaOXA-48, and mcr-1 genes were evaluated by polymerase chain reaction. A total of 27 (7.9%) E. coli isolates were positive for ESBL genes as follows: 24 for blaCTX-M (23 blaCTX-M-2 Group and 1 blaCTX-M-8) and 3 for blaSHV (2 blaSHV-2a and 1 blaSHV-18). A random sample of 32 ceftazidime/cefotaxime-resistant isolates that were negative for ESBL genes were evaluated for the presence of blaCMY-2 and 24 (75%) tested positive. We detected the blaCMY-2 gene in isolates from all farms. All isolates positive for ESBL or blaCMY-2 are considered multidrug resistant (resistant to at least three antibiotic classes). Our results suggest that broiler chickens are an important reservoir of blaCMY-2 and ESBL genes, including blaSHV-2a, described for the first time in animals originating from Brazil in this study, and blaSHV-18, which has never been described in Brazil before. This fact highlights the importance of controlling the use of antibiotics in animal production to reduce environmental sources of resistance genes.

Detection of CTX-M-1 extended-spectrum beta-lactamase among ceftiofur-resistant Salmonella enterica clinical isolates of poultry.

Salmonella enterica resistance to extended-spectrum cephalosporins (ESC) conferred by cefotaximases (blaCTX-M) is a growing concern in the United States. Among food-producing animals, poultry are a major reservoir of ESC-resistant Salmonella. A retrospective study was carried out to further characterize 38 ceftiofur-resistant clinical Salmonella enterica isolates obtained from poultry during 2007-2018. Of the isolates tested, 31 displayed resistance to ceftriaxone and harbored blaCMY-2, whereas 7 isolates demonstrated resistance or reduced susceptibility to cefepime in addition to ceftriaxone resistance. These 7 isolates displayed extended-spectrum ß-lactamase activity, harbored blaCTX-M-1, and were recovered only from recent poultry diagnostic submissions made in 2011-2018 as opposed to the 31 isolates that were recovered in 2007-2018. Further characterization of the blaCTX-M-1 gene determined that it was located on conjugative IncN/ST1 and IncI1/ST87 plasmids in the isolates from commercial turkeys and broilers, respectively. These plasmids have been responsible for extensive spread of blaCTX-M-1 in livestock, poultry, and humans in Europe. Potential transfer of IncN and IncI1 plasmids and/or nontyphoidal Salmonella carrying these plasmids through the food chain, or by other means to humans, may result in treatment failures. Our study demonstrates the importance of further characterization of ceftiofur-resistant S. enterica isolates detected by veterinary diagnostic laboratories to identify the sources of blaCTX-M-1 and to mitigate the spread of ESC-resistant Salmonella in the poultry production pyramid.

Dissemination of Multidrug-Resistant Commensal Escherichia coli in Feedlot Lambs in Southeastern Brazil.

Antimicrobial resistance (AR) is a public health issue since it limits the choices to treat infections by Escherichia coli in humans and animals. In Brazil, the ovine meat market has grown in recent years, but studies about AR in sheep are still scarce. Thus, this study aims to investigate the presence of AR in E. coli isolated from lambs during feedlot. To this end, feces from 112 lambs with 2 months of age, after weaning, were collected on the first day of the animals in the feedlot (day 0), and on the last day before slaughtering (day 42). Isolates were selected in MacConkey agar supplemented with 4 mg/L of ceftiofur and identified by biochemical methods. Isolates were submitted to an antimicrobial susceptibility test by disc-diffusion and PCR to investigate genes for phylogenetic group, virulence determinants and resistance to the several antimicrobial classes tested. The genetic localization of the bla genes detected was elucidated by S1-PFGE followed by Southern blot-hybridizations. The isolates were typed by XbaI-PFGE and MLST methods. Seventy-eight E. coli were isolated from 8/112 (7.1%) animals on day 0, and from 55/112 (49.1%) animals on day 42. Since only fimH was present in almost all E. coli (97.4%) as a virulence gene, and also 88.5% belonged to phylogroups B1 or A, we consider that isolates represent intestinal commensal bacteria. The dendrogram separated the 78 non-virulent isolates in seven clusters, two of which comprised 50 E. coli belonging to ST/CC 1727/446 or ST 3994 recovered on day 42 commonly harboring the genotype bla CMY -2-aac(3)-IIa -tetA-sul1-sul2-floR-cmlA. Special attention should be given to the presence of bla CTX-M-15, a worldwide gene spread, and bla CTX-M-14, a hitherto undetected gene in Enterobacteriaceae from food-producing animals in Brazil. Importantly, E. coli lineages and plasmids carrying bla genes detected here have already been reported as sources of infection in humans either from animals, food, or the environment, which raises public health concerns. Hence, two types of commensal E. coli carrying important AR genes clearly prevailed during feedlot, but lambs are also reservoirs of bacteria carrying important AR genes such as bla CTX-M-14 and bla CTX-M-15, mostly related to antimicrobial treatment failure.

Resistencia de Staphylococcus aureus frente a cefalosporinas en la sepsis neonatal y puerperal / Staphylococcus Aureus Resistance against Cephalosporins in Neonatal and Puerperal Sepsis

Introducción: El mecanismo más común de actividad antibiótica es la interferencia en la síntesis de la pared celular bacteriana. Las cefalosporinas tienen el mismo mecanismo de acción que las penicilinas; sin embargo, tienen un espectro antibacteriano más amplio, son resistentes a muchas b-lactamasas y tienen propiedades farmacocinéticas mejoradas. Objetivos: Identificar por servicios los gérmenes aislados y determinar la resistencia del Staphylococcus aureus a las cefalosporinas. Método: Se realizó un estudio retrospectivo, transversal y descriptivo en hospital Ginecobstétrico de Guanabacoa desde enero de 2014 hasta diciembre de 2016. Se seleccionaron como variables los gérmenes aislados y el patrón de resistencia del germen que predominó frente a todas las generaciones de cefalosporinas. Resultados: En el servicio de neonatología el mayor aislamiento fue en el hemocultivo seguido del catéter venoso (19 pacientes) y tubo endotraqueal. En el servicio de Obstetricia, los loquios y el sitio quirúrgico fue donde se aisló mayor número (69 y 31 pacientes, respectivamente). Conclusiones: El germen más frecuente aislado en ambos servicios fue el Staphylococcus aureus y la resistencia a las cefalosporinas fue muy elevado(AU)

Introduction: The synthesis interference of bacterial cell wall is the most common antibiotic mechanism. Cephalosporins have the same mechanism of action as penicillin. However, they have wider antibacterial spectrum, they are more resistant to B-lactamases and better pharmacokinetics properties. Additionally, cephalosporins have higher activity in front of gram-negative bacteria than penicillin. Objective: To identify isolated germs in these services and to determine the Staphylococcus aureus resistance to cephalosporins. Method: A retrospective, transversal and descriptive study was conducted in Guanabacoa Gynecobstetric hospital from January 2014 to December 2016. selected variables as isolated microorganism, and resistance pattern in front of cephalosporin generations. The isolated germs and the resistance pattern of the germ that prevailed against all generations of cephalosporins were selected as variables. In the Obstetrics Service, the largest number of germs was isolated in the lochia and surgical sites. (69 and 31, respectively). Results: In neonatology service, the most frequent isolation occurred in blood culture (35), venous catheter (19) and endotracheal tube (10). In Obstetric service, the most frequent isolation occurred in liquors (69) and the surgical site isolated (31). Conclusions: Staphylococcus Aureus was the main microorganism isolated in hospital and its cephalosporin resistance was very high(AU)

Review for Analytical Methods for the Determination of Sodium Cephalothin.

Infections are the second leading cause of global morbidity and mortality, therefore it is highly important to study the antimicrobial agents such as cephalosporins. Cephalothin, an antimicrobial agent that belongs to the class of cephalosporins, has bactericidal activity and it is widely used in the Brazilian health system. In literature, some analytical methods are found for the identification and quantification of this drug, which are essential for its quality control, which ensures maintaining the product characteristics, therapeutic efficacy and patient's safety. The aim of this article is to review the available information on analytical methods for cephalothin. Thus, this study presents a literature review on cephalothin and the analytical methods developed for the analysis of this drug in official and scientific papers. It is essential to note that most of the developed methods used toxic and hazardous solvents, which makes necessary industries and researchers choose to develop environmental-friendly techniques, which will contribute to the harmonization of science, human, and environmental health.

Phenotypic and molecular characterization of Klebsiella spp. isolates causing community-acquired infections.

Klebsiella spp. isolates from community-acquired infections were characterized. A total of 39 Klebsiella spp. isolates were obtained from outpatients at four rural hospitals in Mexico (2013-2014). The biochemical tests identified all as being K. pneumoniae. The molecular multiplex-PCR test identified 36 (92.4%) K. pneumoniae isolates and one (2.5%) K. variicola isolate, and phylogenetic analysis of the rpoB gene identified two isolates (5.1%) belonging to K. quasipneumoniae subsp. quasipneumoniae and K. quasivariicola. The last one was confirmed by phylogenetic analysis of six-loci concatenated genes. Mostly the isolates were multidrug resistant; however, a minority were extended-spectrum ß-lactamase producing (10.2%). The extended-spectrum ß-lactamase CTX-M-15 gene was identified in these isolates. Analysis of biofilm production and the hypermucoviscosity phenotype showed a total of 35 (92.3%) and seven (17.9%) of the isolates were positive for these phenotypes respectively. The K2 (4/39, 10.2%), K5 (2/39, 5.1%) and K54 (1/39, 2.5%) serotypes were identified in seven (17.9%) of the isolates, and only 28.5% (2/7) hypermucoviscous isolates were positive for the K2 and K5 serotypes. In general, the sequence type (ST) analysis and phylogenetic analysis of seven multilocus sequence typing loci were heterogeneous; however, ST29 was the most prevalent ST in the analysed isolates, accounting for 19% (4/21) of the total isolates. Two of the four ST29 isolates had the hypermucoviscosity phenotype. The virulence factors for fimbriae were the most prevalent, followed by siderophores. Community-acquired infections are caused by various species from Klebsiella genus, with different profiles of antibiotic resistance and heterogeneous virulence factors.

High Prevalence of CTX-M-1-Like Enzymes in Urinary Isolates of Escherichia coli in Guayaquil, Ecuador.

Escherichia coli is one of the major causes of urinary tract infections in primary healthcare, and treatment is more complicated due to the increase in antibiotic resistance. Extended-spectrum ß-lactamases are the most common mechanism of resistance against third-generation cephalosporin, and CTX-M-like are among the most prevalent. The aim of our work is to investigate the prevalence of blaCTX-M in isolates of E. coli obtained from samples of patients without previous known contact with the hospital. Ninety-four E. coli isolates with resistance to third-generation cephalosporin were collected between 2008 and 2013 in Guayaquil, Ecuador. Polymerase chain reaction, followed by sequencing, was performed to identify the type of blaCTX-M-Like. Enterobacterial repetitive intergenic consensus (ERIC)-PCR was carried out to determine the clonal relationship between isolates. These results show an increase in resistance to third-generation cephalosporin from 10.58% to 23.96%. CTX-M-15 was the most prevalent mechanism of resistance being that the isolates were not clonal. Overall, these results show an increase in antibiotic resistance in the community over time, suggesting that more precise antibiotic stewardship needs to be implemented to control the dissemination of antibiotic-resistant bacteria in this region.

Pharmacological aspects and spectrum of action of ceftazidime-avibactam: a systematic review.

PURPOSE: Ceftazidime-avibactam is an antimicrobial association active against several Enterobacteriaceae species, including those resistant to carbapenem. Considering the importance of this drug in the current panorama of multidrug-resistant bacteria, we performed a systematic review about ceftazidime-avibactam with emphasis on clinical and pharmacological published data. METHODS: A systematic search of the medical literature was performed. The databases searched included MEDLINE, EMBASE and Web of Science (until September 2017). The search terms used were 'avibactam', 'NXL104' and 'AVE1330A'. Bibliographies from those studies were also reviewed. Ceftazidime was not included as a search term, once relevant studies about avibactam in association with other drugs could be excluded. Only articles in English were selected. No statistical analysis or quality validation was included in this review. RESULTS: A total of 151 manuscripts were included. Ceftazidime-avibactam has limited action against anaerobic bacteria. Avibactam is a potent inhibitor of class A, class C, and some class D enzymes, which includes KPC-2. The best pharmacodynamic profile of ceftazidime-avibactam is ƒT > MIC, validated in an animal model of soft tissue infection. Three clinical trials showed the efficacy of ceftazidime-avibactam in patients with intra-abdominal and urinary infections. Ceftazidime-avibactam has been evaluated versus meropenem/doripenem in hospitalized adults with nosocomial pneumonia, neutropenic patients and pediatric patients. CONCLUSION: Ceftazidime-avibactam has a favorable pharmacokinetic profile for severe infections and highly active against carbapenemases of KPC-2 type.

Radiolytic studies of cefozopran hydrochloride in the solid state

Background: The radiation sterilization is one of the best methods for sterilizing vulnerable degradation drugs like cefozopran hydrochloride. Results: Chemical stability of radiosterylized cefozopran hydrochloride, was confirmed by spectrophotometric and chromatographic methods. EPR studies showed that radiation has created some radical defects whose concentration was no more than several dozen ppm. The antibacterial activity of cefozopran hydrochloride irradiated with a dose of 25 kGy was unaltered for Gram-positive bacteria but changed for two Gram-negative strains. The radiation sterilized cefozopran hydrochloride was not in vitro cytotoxic against human CCD39Lu normal lung fibroblast cell line. Conclusions: Cefozopran hydrochloride in solid state is not resistant to radiation sterilization and this method cannot be used for sterilization of this compound.