[Simulation of an outbreak of Acinetobacter baumannii in hospitals]

OBJECTIVE

Acinetobacter baumannii infections have increased over time becoming a significant issue. Consequently, those applications that allow to predict the evolution of an outbreak and the relevance of the different control methods, are very important. The design of mathematical models plays a central role in this topic.

METHODS

Development of a deterministic mathematical model based on ordinary differential equations whose variables and parameters are defined upon the basis of knowledge of the epidemiology and characteristics of A. baumannii. This model is analyzed from a qualitative point of view and, also, its computational implementation is derived.

RESULTS

Several simulations were obtained developed from different initial conditions. The qualitative analysis of these simulations provides formal evidence of most effective control measures.

CONCLUSIONS

The implementation of the computational model is an extremely useful tool in terms of managing A. baumannii outbreaks. There is mathematical proof of the fact that the observance of efficient hygiene and screening rules reduces the number of infected patients.

The clinical microbiologist before the taxonomic changes in the genus Clostridium

The various species included in the genus Clostridium are very heterogeneous, both from a phenotypic and a phylogenetic point of view. The advances in polyphasic taxonomy, particularly in phylogeny, are allowing to resolve this dysfunction reclassifying several species in other genres, although there is still work to be done. Changes in generic denominations are quite normal in taxonomy, but can turn into a problem when they affect species with strong clinical impact and that have been recognised for a long time, as in the case of some traditional Clostridium species. After knowing these changes clinical microbiologists, in whose work taxonomy is an essential tool, should evaluate what matters most, if the communication with other health professionals or the phylogeny, and think about the possibility of combining both things. This paper reviews some of the taxonomic changes that have took place in well-known Clostridium species that can be clinically interesting and evaluates, as far as possible, their significance in the scientific and medical communication.

[Changes in the epidemiology of Clostridium difficile infection during 2005-2014 in Salamanca, Spain]

OBJECTIVE

To know the most relevant epidemiological features of Clostridium difficile infection (CDI) between 2005- 2014 in the province of Salamanca (Spain).

METHODS

Descriptive cross-sectional study carried out through review of the clinical microbiologic records at Complejo Asistencial Universitario de Salamanca. Detection was performed according to standard methodology.

RESULTS

2.6% of stool samples analyzed for detection of C. difficile toxins (9,103) were positive. The average prevalence was 6.8 cases per 100,000 people per year. The mean age was 65 ± 21.4 years and the median 70 years. 59% of cases occurred in patients over 64 years, with an average prevalence of 16.5 (4 times higher than the 15-64 group). Most cases (86.4%) occurred in hospitalized patients, and the group of over 64 had the highest percentage of hospital CDI, with 55%.

CONCLUSIONS

A significant increase in the number of requests and in the prevalence of CDI over the decade studied is observed, and prevalence rates were significantly lower than those of other studies. The percentage of CDI increased significantly in both inpatient and community. Age and hospitaliza-tion were risk factors for developing CDI. After the introduc-ion of a molecular detection technique in 2014, the prevalence increased, being 2.5 times higher than 2013.

Comparative study of bacterial translocation control with nitric oxide donors and COX2 inhibitor

OBJECTIVE AND DESIGN

To evaluate the beneficial effects of exogenous NO and an inhibitor of the COX2, and their action levels in a model of SIRS/bacterial translocation (BT) induced by Zymosan A(®).

MATERIAL AND METHODS

Ninety Wistar rats were submitted to different treatments, and after 12h and 24h they were anaesthetized in order to collect blood, mesenteric lymph nodes, and kidney for subsequent biochemical analyses and microbiological examinations.

TREATMENTS

A nitric oxide donor, Molsidomine(®), was compared with a COX2 inhibitor, Celecoxib(®).

METHODS

Zymosan A(®) was administered to Wistar rats. The animals were divided into 6 groups: one group for survival study, Group (1) No manipulation (BASAL); Group (2) vehicle of Zymosan A(®) given intraperitoneally (SHAM); Group I (control), with Zymosan A(®) (0.6g/kg) intraperitoneally; Group II (Molsidomine), with Molsidomine(®) (4mg/kg) through the penis dorsal vein, 30min prior to administration of the Zy(®) (0.6g/kg); Group III (Celecoxib), with Celecoxib(®) (400mg/kg) orally through a stomach tube, 6h prior to administration of the Zy (0.6g/kg).

DETERMINATIONS

The parameters survival, bacterial translocation, renal function, neutrophil accumulation, oxygen free radicals (OFR), detoxifying enzymes, and cytokines were measured at different times after Zymosan administration.

RESULTS

The model established induced a mortality rate of 100% and generated BT and systemic inflammatory response syndrome (SIRS) in all samples. It also significantly increased all variables, with p<.001 for MPO and all pro-inflammatory cytokines, and p<.01 for all OFR. Treatment with Molsidomine reduced mortality to 0%, decreased BT, MPO, pro-inflammatory cytokines and OFR (p<.001) significantly and increased IL-10 and IL-6 production. Moreover, the Celecoxib(®) showed a lower capacity for SIRS regulation.

CONCLUSIONS

The exogenous administration of NO prevented BT and controlled SIRS. Therefore these results suggest that Molsidomine could be used as a therapeutic strategy to protect against BT.

[Noma/Cancrum oris: a neglected disease]

Noma is an aggressive orofacial gangrenous pathology that damages hard and soft tissues of the mouth and the face. Throughout the centuries it has been present around the globe, but nowadays it has practically disappeared from developed countries and mainly affects children from the most disadvantaged places, especially in Africa. Noma disease is a multifactorial process; malnutrition, debilitating diseases (bacterial or viral systemic diseases, HIV-associated immunosuppression, etc.) and intraoral infections are some of the factors implied. The characteristic tissue necrosis is produced by a polymicrobial infection. Fusobacterium necrophorum, Prevotella intermedia, Prevotella melaninogenica, Fusobacterium nucleatum, Bacteroides fragilis, Bacillus cereus, Trueperella pyogenes, spyrochetes, etc, are some of the species that have been isolated from the affected areas. Without treatment, noma is lethal in a short period of time, and the patients that survive show severe sequelae that hinder their life and interpersonal relationships. The aim of this paper is to unify the existing information and to promote wider knowledge and awareness among the population.

[Prevention of an outbreak of Acinetobacter baumannii in intensive care units: study of the efficacy of different mathematical methods]

INTRODUCTION

Although in past decades, Acinetobacter baumanni infections have been sporadically identified in hospitals, nowadays the nosocomial infections due to this pathogen have notably increased. Its importance is due to its multidrug- resistance, morbidity and mortatility in healthcare settings. Consequently, it is important to predict the evolution of these outbreaks in order to stablish the most efficient control measures. There are several experimental studies shown that the compliance with hand and environmental hygiene and the efficient management of the healthcare work help to control the evolution of these outbreaks. The goal of this work is to formally proof these experimental results by means of the analysis of the results provided by the model.

METHODS

A stochastic mathematical model based on cellular automata was developed. The variables and parameters involved in it have been identified from the knowledge of the epidemiology and main characteristics of Acinetobacter infections.

RESULTS

The model provides several simulations from different initial conditions. The analysis of these results proofs in a formal way that the compliance with hand and environmental hygiene and an efficient plannification of the work of healtcare workers yield a decrease in the colonized patients. Moreover, this is the unique model proposed studying the dynamics of an outbreak of A. baumanni.

CONCLUSIONS

The computational implementation of the model provides us an efficient tool in the management of outbreaks due to A. baumanni. The analysis of the simulations obtained allows us to obtain a formal proof of the behaviour of the measures for control and prevention.

[Polio, the long walk to the endgame]

Although the WHO original target date for the global eradication of poliomyelitis was the year 2000 -thanks to vaccination and institutional, public and private, resources for that purpose-, in 2013 the disease remained endemic in three countries, Afghanistan, Pakistan and Nigeria, and some cases were described in five others. The circulation of wild type 1 poliovirus in Israel, Gaza and the West Bank and the cases in Syria were a wakeup call, as at that time there were polioviruses derived from the oral vaccine that are still circulating among the human population and can cause the development of the disease. Travelling "from" and "to" endemic areas are factors to consider in poliovirus exportation and in its spread when it reaches areas with poor immunogenicity. Wars, terrorism, intolerance, lack of culture and proliferation of anti-vaccine groups and the rise of the anti-vaccination movement are important factors in the maintenance and expansion of the virus and in the "non-vaccination" against it. Based on the international situation to date, the Emergency Committee of WHO met in May 2014 to address the problem. It is still necessary to enhance the knowledge of the disease and its agent. In the first case to perform a differential diagnosis of flaccid paralysis and to continue vaccination programs, and in the second case to keep studying and looking for the poliovirus in environmental samples, which is a model for the study of many other viruses.

[Epidemiology of Clostridium difficile-associated disease (CDAD) in Salamanca]

INTRODUCTION

Clostridium difficile infection is considered a major cause of nosocomial diarrhoea in developed countries and is increasingly becoming more important as an etiologic agent of community diarrhoea, also in patients without risk factors.

METHOD

Beginning in May 2011, the aim of our study is to know the characteristics of patients suffering from C. difficile Associated Disease in Salamanca University Hospital, collecting their data in a survey conducted for this purpose. A case was defined as a patient with compatible clinical and positive microbiological diagnosis.

RESULTS

After 18 months of study, 41 cases had been documented representing an incidence of 1.15 cases per 10,000 patient-days. Patients were hospitalized (37) or health care associated (4), females (54%), age ≥ 65 years (56%) with prior antibiotic treatment (80%), most had diarrhea after the third day of admission, less than three weeks and without blood. Most were treated with metronidazole alone (78%), 19% with metronidazole and vancomycin, and the remaining percentage was resolved without treatment. Recurrences were about 20% and 7 (17%) died.

CONCLUSIONS

The characteristics of our patients with C. difficile - associated disease are the same as those reported by other authors. Local surveillance is important in order to study the endemic and epidemic C. difficile infection. According to published epidemiological changes, we should be able to develop strategies from the Microbiology laboratories that will improve diagnosis of the disease.

[Mathematical modelling of the propagation of infectious diseases: where we came from, and where we are going]

This work deals with the study of the use of mathematical models to simulate the spreading of infectious diseases. There is no doubt about the importance of the use of computational tools that allow the health staff to model and predict the spreading of an infectious disease. Using such tools one can establish and simulate disease control strategies. The development of such technologies is a multidisciplinary issue; in this sense, the mathematical algorithms -that must be computationally implemented- play a central role. The main goal of this work is to highlight among health community the increasing importance of the use of mathematical models for epidemic disease spreading. Consequently, the main features of such models are introduced and their classification is stated taking into account the behavior, the basic population unit or the mathematical objects used. An exhaustive search of related papers through the most important databases (Medline and Web of Science) are performed. The main conclusion obtained from this work is the central role that mathematical models can play in the simulation of epidemic spreading; moreover,some ideas about the future research are stated.

[Anaerobic bacteria 150 years after their discovery by Pasteur]

In 2011 we celebrated the 150th anniversary of the discovery of anaerobic bacteria by Louis Pasteur. The interest of the biomedical community on such bacteria is still maintained, and is particularly focused on Clostridium difficile. In the past few years important advances in taxonomy have been made due to the genetic, technological and computing developments. Thus, a significant number of new species related to human infections have been characterised, and some already known have been reclassified. At pathogenic level some specimens of anaerobic microflora, that had not been isolated from human infections, have been now isolated in some clinical conditions. There was emergence (or re-emergence) of some species and clinical conditions. Certain anaerobic bacteria have been associated with established infectious syndromes. The virulence of certain strains has increased, and some hypotheses on their participation in certain diseases have been given. In terms of diagnosis, the routine use of MALDI-TOF has led to a shortening of time and a cost reduction in the identification, with an improvement directly related to the improvement of data bases. The application of real-time PCR has been another major progress, and the sequencing of 16srRNA gene and others is currently a reality for several laboratories. Anaerobes have increased their resistance to antimicrobial agents, and the emergence of resistance to carbapenems and metronidazole, and multi-resistance is a current reality. In this situation, linezolid could be an effective alternative for Bacteroides. Fidaxomicin is the only anti-anaerobic agent introduced in the recent years, specifically for the diarrhoea caused by C.difficile. Moreover, some mathematical models have also been proposed in relation with this species.

[Matematical modeling of antibiotic resistance: perspectives from a meta-analysys]

The antibiotic resistance is one of the greatest challenges of the international health community. The study of antibiotic resistance must be a multidisciplinary task and, in this sense, the main goal of this work is to analyze the role that Mathematical Modeling can play in this scenario. A qualitative and cuantitative analysis of the works published in the scientific literature is done by means of a search in the most important databases: MEDLINE, SCOPUS and ISI Web of Science. Consequently, there are few papers related to our topic but the existing works have been published in high-quality and impact international journals. Moreover, we can state that mathematical models are a very important and useful tool to analyze and study both the treatments protocols for resistance prevention and the assesment of control strategies in hospital environtment, or the prediction of the evolution of diseases due to resistant strains.

[Antibiotheraphy in the 21st century, antibacterials for the second decade. Posibilities or realities in the future?]

A review of some antibacterial products is done motivated by the serious situation arisen by the antimicrobial resistance in bacteria. The attention is focus on those drugs with suitable antimicrobial properties that have prospects to be commercialized in the next years because of they are undergoing a clinical development phase (I, II, III). The search for these antibacterial products has been done by an exhaustive study of conference proceedings and web pages of international congresses on chemotherapy, infectious diseases and new antimicrobial drugs. Some of the new antibacterial products acts on known targets, and they belong to already used families. Furthermore, the great majority acts against the gram-positive bacterium. There is also some limited-spectrum antimicrobial drug whose use would minimize the adverse biological effects.

[Reliability of MALDI-TOF mass spectrometry in the identification of anaerobic bacteria]

AIM OF THE STUDY

MALDI-TOF mass spectrometry (MS) is becoming a major resource in the Clinical Microbiology laboratory. Results on some groups of microorganisms are still controversial. We have studied the reliability of MALDI-TOF MS for the identification of anaerobic clinical isolates was studied compared to conventional biochemical methods, with rRNA 16S sequencing being used as a reference when discrepancies arose.

MATERIAL AND METHODS

A total of 126 anaerobic bacteria clinical isolates were studied by using API20A kits (bioMérieux, Marcy l'Étoile, France) and MALDI-TOF MS (Autoflex II, Bruker Daltonics, Germany), and using the data library BioTyper 2.0 (Bruker Daltonics, Germany). When discrepancies arose, or MALDI-TOF MS was not able to identify any microorganism, rRNA 16S sequencing was used as the reference standard.

RESULTS

The biochemical method and MALDI-TOF MS agreed in identifying 60.9% of isolates at species level, and 20.3% of isolates at genus level. Among the 48 discrepancies observed, rRNA 16S sequencing supported MALDI-TOF MS identification, at species level, in 32 isolates (66.7%), and in 8 isolates (16.7%) at genus level. rRNA 16S sequencing supported biochemical identification in only two isolates (4.2%) at species level, and in 26 isolates (54.2%) at genus level. The eight isolates for which MALDI-TOF MS did not manage to identify, or the identification obtained was rejected by sequencing, belonged to species that are still not added to the BioTyper II data library.

CONCLUSIONS

Results obtained in this study show that, overall, MALDI-TOF MS identification of anaerobic bacteria is more reliable than identification obtained by conventional biochemical methods (24% more correct identifications at species level). The number of major errors (incorrect identification at the genus level) is also 2.5-times lower. Moreover, all the major errors obtained by MALDI-TOF MS were due to the absence of some species in the data library. Thus, when data libraries are more complete, reliability differences between both methods will probably be even higher.

[Microbiological diagnosis of intra-abdominal infections]

Intra-abdominal infections represent a large and wide group of diseases which include intra- and retro-peritoneal infections. Some of them could be defined as uncomplicated, where the infectious process is limited to the organ or tissue of origin (appendicitis, diverticulitis, cholecystitis…). Complications occur when the infection spreads to the peritoneum, triggering localised peritonitis and abdominal abscesses. Most intra-abdominal infections are due to perforation or inflammation of the intestinal wall. The microorganisms that cause these infections come from the gastrointestinal flora, and therefore produce polymicrobial infections mixed with a predominance of anaerobic bacteria. Microbiological diagnosis is essential to determine the aetiology and the susceptibility of antimicrobial agents of the microorganism involved, especially in nosocomial infections or in community infections in predisposed patients due to increasing bacterial resistance to antimicrobial agents, multidrug resistance and fungal involvement. Despite the advances in microbiological diagnosis, in the case of intra-abdominal infections it still remains direct, being based on stains and cultures, the most notable progress is the introduction of mass spectrometry (MALDI-TOF) for the rapid identification of the pathogens involved. This review will provide recommendations on the collection, transport and microbiological processing of clinical specimens. Comments on the pathogenesis, clinical and microbiological diagnosis of peritonitis primary, secondary, tertiary and peritonitis (and other infections) associated with peritoneal dialysis, intra-abdominal abscesses (intraperitoneal, retroperitoneal and visceral), biliary tract infections, appendicitis and diverticulitis are also presented.

Update on pathogenesis and diagnosis of intravascular catheter-related infections

Infections associated with the use of intravascular catheters cause a substantial morbidity and mortality. New knowledge in the pathogenesis of catheter related bloodstream infections has led to advances in the prevention and management of these infections. The purpose of the present chapter is to review the most relevant data published recently on pathogenesis and diagnosis of intravascular catheter-related infections. It is focus in four different aspects: a) pathogenesis of catheter-related infections and particularly factors affecting biofilm formation and modulation; b) pathogenesis of intravascular catheter-related infections caused by Staphylococcus lugdunensis; c) news on microbiological diagnosis of catheter-related bacteremia; and d) evaluation of current use of blood cultures in the era of continuous monitoring blood cultures systems.

Microorganisms direct identification from blood culture by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) allows a fast and reliable bacterial identification from culture plates. Direct analysis of clinical samples may increase its usefulness in samples in which a fast identification of microorganisms can guide empirical treatment, such as blood cultures (BC). Three hundred and thirty BC, reported as positive by the automated BC incubation device, were processed by conventional methods for BC processing, and by a fast method based on direct MALDI-TOF MS. Three hundred and eighteen of them yield growth on culture plates, and 12 were false positive. The MALDI-TOF MS-based method reported that no peaks were found, or the absence of a reliable identification profile, in all these false positive BC. No mixed cultures were found. Among these 318 BC, we isolated 61 Gram-negatives (GN), 239 Gram-positives (GP) and 18 fungi. Microorganism identifications in GN were coincident with conventional identification, at the species level, in 83.3% of BC and, at the genus level, in 96.6%. In GP, identifications were coincident with conventional identification in 31.8% of BC at the species level, and in 64.8% at the genus level. Fungaemia was not reliably detected by MALDI-TOF. In 18 BC positive for Candida species (eight C. albicans, nine C. parapsilosis and one C. tropicalis), no microorganisms were identified at the species level, and only one (5.6%) was detected at the genus level. The results of the present study show that this fast, MALDI-TOF MS-based method allows bacterial identification directly from presumptively positive BC in a short time (<30 min), with a high accuracy, especially when GN bacteria are involved.

[New anaerobic bacterial species in human infections]

This review offers succinct, precise, and complete information based on the available data concerning new anaerobic bacterial species involved in infectious diseases in humans. All hitherto undescribed species, those not previously implicated in clinical conditions, those with confirmed implication in human disease that have not been characterized, and those that have undergone taxonomic changes are considered to be "new".

Study of the efficacy of Coated VICRYL Plus® Antibacterial suture (coated Polyglactin 910 suture with Triclosan) in two animal models of general surgery

OBJECTIVES

To evaluate the efficacy in vitro and in vivo of a new antibacterial suture (PGAB) compared with a traditional braided suture (PG). Our primary goals were to study microbiological effectiveness and impact on wound healing of PGAB vs PG. Secondary goal was to analyze influence on inflammatory response.

METHODS

In vitro study: clinical samples of Staphylococcus epidermidis, Staphylococcus aureus, S. hominis, Staphylococcus haemolyticus, Staphylococcus auricularis, Enterococcus faecalis, Corynebacterium spp. and Escherichia coli were studied. We also implanted a flat mesh in 10 minipigs, four incisions each (two PG and two PGAB) two contaminated with S. epidermidis and two not contaminated. Finally, we performed four colic anastomosis in each of 10 minipigs, two contaminated with E. coli and two not contaminated (two PG and two PGAB). We studied the inflammatory and wound healing processes in both models.

RESULTS

We observed a bactericidal efficacy of PGAB against grampositive, and bacteriostatic effect against E. coli. Mesh study: recovered CFU were lower in the group PGAB vs PG. In the group PGAB, inflammatory mediators' concentrations were lower. In the group PGAB, concentrations of wound healing mediators were normal. Colic anastomosis: recovered CFU were lower in the group PGAB vs the group PG. In the group PGAB we observed a reduction of inflammatory mediators. In the group PGAB we observed normalized concentrations of wound healing mediators.

CONCLUSIONS

This study demonstrates microbiological efficacy of PGAB, that normalizes wound healing process, and an anti-inflammatory effect.

[Movies as a teaching resource for infectious diseases and clinical microbiology]

Since its inception, the cinema has constantly provided a reflection of infectious diseases because of their omnipresence in life and their importance to individuals and society. Few infectious diseases escape its eye, to the extent that the cinema constitutes an authentic treatise on these phenomena. The cinema is a very valuable educational resource, able to supplement classical teaching methods and to encourage critical thinking among students. The enormous flow of information, images, sounds, consequences, situations, and points of view that it provides should not be wasted and can be of great use, both in the spread of ideas and in training in infectious diseases and clinical microbiology.

[Clinical and analytic diagnostic evaluation of deep venous thrombosis of the lower limbs]

BACKGROUND

Diagnosis of deep-vein thrombosis (DVT) of lower limbs has changed in recent years. The objective of our study was to analyze the diagnostic accuracy of a combination of clinical and epidemiological data and the D-Dimer plasma levels in this entity.

PATIENTS AND METHODS

Clinical (symptoms and signs) and epidemiological data, personal and family history, and D-dimer plasma levels or positivity were reviewed, on the admittance, in 108 patients to whom a phlebography was performed due to a suspected DVT.

RESULTS

Phlebography was positive in 76 cases (70.37%). Logistic regression analysis determined a prediction model of the diagnostic of DVI including a combination of both D-dimer plasma levels or positivity and pain along the deep venous involved area.

CONCLUSION

Combination of D-dimer testing and pain along the distribution of the deep venous area is useful as an initial diagnostic approach to the DVI of the lower limbs.

In vitro activities of six new fluoroquinolones against Brucella melitensis

We have tested the in vitro activities of eight fluoroquinolones against 160 Brucella melitensis strains. The most active was sitafloxacin (MIC at which 90% of the isolates are inhibited [MIC90], 0.12 microg/ml). In decreasing order, the activities (MIC90s) of the rest of the tested fluoroquinolones were as follows: levofloxacin, 0.5 microg/ml; ciprofloxacin, trovafloxacin, and moxifloxacin, 1 microg/ml; and ofloxacin, grepafloxacin, and gatifloxacin, 2 microg/ml.

In vitro activity of BAY y 3118, and nine other antimicrobial agents against anaerobic bacteria

The antibacterial activity of BAY y 3118, a new chlorofluoroquinolone, was determined against 257 strains of anaerobic bacteria and compared with the activities of ofloxacin, ciprofloxacin, sparfloxacin, imipenem, cefoxitin, clindamycin, chloramphenicol, metronidazole, and ornidazole. Overall, BAY y 3118 was the most active agent tested against the Bacteroides fragilis group. Its activity (MIC90, 0.5 mg/L) was 16-fold lower than that of sparfloxacin (MIC90, 8 mg/L), and more than 100-fold lower than that of ofloxacin (MIC90, 64 mg/L) and ciprofloxacin (MIC90, 128 mg/L) against the group. No strains belonging to this group were resistant to metronidazole (MICs range, 0.12-2 mg/L) and ornidazole (MICs range, 0.12-4 mg/L). BAY y 3118 was more active than those quinolones against Prevotella and Porphyromonas spp., Fusobacterium spp., Clostridium perfringens and C. difficile (MIC90, 0.12, 0.06, 0.12 and 0.25 mg/L, respectively). The activity of BAY y 3118 against Peptostreptococcus spp. (MIC90, 1 mg/L) was slightly lower than that of the other Gram-positive bacteria tested. In general, BAY y 3118 was more active than cefoxitin, and it was superior to antianaerobic chemical agents like metronidazole, ornidazole and clindamycin. Pharmacokinetic and clinical trials are required to define the role of BAY y 3118 in the treatment of anaerobic infections.

Multicenter Spanish study of ciprofloxacin susceptibility in gram-negative bacteria. The Spanish Study Group on Quinolone Resistance

The susceptibility of 2,426 gram-negative bacteria obtained from 18 Spanish hospitals to ciprofloxacin was evaluated. Among different medical centers, susceptibility to ciprofloxacin ranged from 83 to 100% for Enterobacteriaceae, from 35 to 100% for Pseudomonas aeruginosa, from 0 to 100% for Xanthomonas maltophilia, Acinetobacter spp. and other gram-negative non-fermenting bacilli, and from 33 to 100% for Campylobacter spp. All clinical isolates of Haemophilus influenzae, Moraxella catarrhalis and Neisseria gonorrhoeae were susceptible to ciprofloxacin.

Esophageal brucellosis: a new location of Brucella infection

The case of a patient with acute brucellosis presenting as lower dysphagia from a paracardial esophageal mass is described. Brucella melitensis biotype 3 was isolated from cultured esophageal biopsy material. This is the first case of esophageal brucellosis described in the literature.

Activity of BAY y 3118, a novel 4-quinolone, against Brucella melitensis

We have tested the in-vitro activities of BAY y 3118, a new chlorofluoroquinolone, ciprofloxacin, sparfloxacin, streptomycin, tetracycline and rifampin against 59 strains of Brucella melitensis. BAY y 3118 (MIC90 0.12 mg/L) was twice as active as sparfloxacin and tetracycline (MIC90 0.25 mg/L). The activity of ciprofloxacin, rifampin and streptomycin (MIC90 0.5, 2, and 8 mg/L, respectively) was, respectively, four-, sixteen-, and more than sixty-fold lower than that of BAY y 3118.

[Focal salmonellosis in Spain. Presentation of 14 cases and review of the literature]

A study of the 14 focal salmonelloses diagnosed in the Hospital Clínico Universitario from Salamanca during the last years is presented, along with a review of the major series reported in Spain. The most common focal salmonelloses were osteoarticular, representing one third of cases. The most common underlying condition was diabetes mellitus, which involved more than 40% of patients. The pathogenetical peculiarities of salmonellosis in these patients and their relation with the higher prevalence of focal salmonellosis in particular diseases are discussed.

Evolution of antimicrobial susceptibility in isolates of the Bacteroides fragilis group in Spain

The species included in the Bacteroides fragilis group are the most frequent nontoxigenic anaerobic bacteria pathogenic to humans. The emergence and increase of resistance to antibiotics among this group make surveillance and state-of-the-art knowledge important. We studied the evolution of resistance to antibiotics in B. fragilis group organisms isolated at the University Clinical Hospital at Salamanca, Spain, from 1975 to 1987. No resistance to imipenem, chloramphenicol, or metronidazole was detected. The frequency of resistance to clindamycin was in the range of 6%-7%. Resistance to moxalactam, cefoxitin, mezlocillin, and piperacillin has increased steadily and is currently approximately 20%-25%.

[In vitro activity of 16 antimicrobial agents against Helicobacter (Campylobacter) pylori]

Campylobacter pylori has been associated with the etiology of gastritis and duodenal ulcer. It has been shown that several drugs, among them a variety of antimicrobials, eliminate C. pylori from gastric mucosa at least for a time, resulting in an improvement of the patients' symptoms. The activity of 16 antimicrobials (ampicillin, cefazolin, cefuroxime, cefotaxime, imipenem, aztreonam, tigemonam, erythromycin, vancomycin, nalidixic acid, colistin , norfloxacin, ciprofloxacin, difloxacin, ofloxacin and perfloxacin) was tested against 30 clinical isolates of C. pylori. The antimicrobials showing the highest activity were ampicillin, imipenem and ciprofloxacin, followed by cefazolin, cefuroxime, cefotaxime, aztreonam, tigemonam, erythromycin and difloxacin. Nalidixic acid, colistin and vancomycin were virtually ineffective against C. pylori.

Review of pulmonary brucellosis: a case report on brucellar pulmonary empyema

In certain geographic areas, among which most South European countries are included, brucellosis continues to be an important health problem. Despite the disease's continued high prevalence, the advances made in its diagnosis and treatment have contributed to the rarity of different focal locations, such as the lung. Formerly, these occurrences were much more frequent. The present work offers a review of the literature on pulmonary brucellar affection and describes a case report of brucellar pulmonary empyema with isolation of Brucella melitensis from the pleural exudate. This constitutes an exceptional circumstance even in areas considered hyperendemic, such as a large part of Spain.

The in-vitro activity of SQ 82,291, a new monobactam, in comparison with aztreonam

The in-vitro activity of a new monobactam antibiotic, SQ 82,291, was compared with that of aztreonam against 529 strains of aerobic and facultatively anaerobic bacteria. SQ 82,291, which is absorbed orally when administered as an ester, has shown good activity against different bacteria of the family Enterobacteriaceae and Haemophilus influenzae. The susceptibility of SQ 82,291 is lower than that to aztreonam in the species that were sensitive and SQ 82,291 showed no activity at all against staphylococci and strict anaerobes (like aztreonam); unlike aztreonam SQ 82,291 was not effective against Pseudomonas aeruginosa.