The many dimensions of combination therapy: How to combine antibiotics to limit resistance evolution.

In combination therapy, bacteria are challenged with two or more antibiotics simultaneously. Ideally, separate mutations are required to adapt to each of them, which is a priori expected to hinder the evolution of full resistance. Yet, the success of this strategy ultimately depends on how well the combination controls the growth of bacteria with and without resistance mutations. To design a combination treatment, we need to choose drugs and their doses and decide how many drugs get mixed. Which combinations are good? To answer this question, we set up a stochastic pharmacodynamic model and determine the probability to successfully eradicate a bacterial population. We consider bacteriostatic and two types of bactericidal drugs-those that kill independent of replication and those that kill during replication. To establish results for a null model, we consider non-interacting drugs and implement the two most common models for drug independence-Loewe additivity and Bliss independence. Our results show that combination therapy is almost always better in limiting the evolution of resistance than administering just one drug, even though we keep the total drug dose constant for a 'fair' comparison. Yet, exceptions exist for drugs with steep dose-response curves. Combining a bacteriostatic and a bactericidal drug which can kill non-replicating cells is particularly beneficial. Our results suggest that a 50:50 drug ratio-even if not always optimal-is usually a good and safe choice. Applying three or four drugs is beneficial for treatment of strains with large mutation rates but adding more drugs otherwise only provides a marginal benefit or even a disadvantage. By systematically addressing key elements of treatment design, our study provides a basis for future models which take further factors into account. It also highlights conceptual challenges with translating the traditional concepts of drug independence to the single-cell level.

Disposables used cumulatively in routine IVF procedures could display toxicity.

STUDY QUESTION: Is there a cumulative toxicity of disposables used in IVF procedures? SUMMARY ANSWER: A toxicity may be detected when consumables are used cumulatively, while no toxicity is detected when the same consumables are used and tested individually. WHAT IS KNOWN ALREADY: Many components of items used in IVF laboratories may impair human embryonic development. Consequently, it is necessary to screen all reagents and materials which could be in contact with gametes and embryos. Toxicity tests, such as the mouse embryo assay and the human sperm motility assay (HSMA), are used by manufacturers as quality control tools to demonstrate the safety of their products. This evaluation is currently individually performed for each single consumable. However, during an IVF cycle, several devices are used sequentially, potentially creating a cumulative exposure to chemical contaminants, which could not be detected for individually tested consumables. STUDY DESIGN, SIZE, DURATION: The objective of this observational study conducted from March 2021 to October 2022 was to evaluate with the HSMA methodology if there was a cumulative toxicity when several disposables are sequentially used. Fourteen categories of consumables currently used in routine IVF procedures were studied, which included devices used for sperm and oocyte collection (cups, condoms, and oocyte aspiration needles), manipulation (flasks, tubes, tips, pipettes, embryo transfer catheters, syringes, and gloves), culture (dishes), and storage (straws). PARTICIPANTS/MATERIALS, SETTING, METHODS: After obtaining patient consent, the surplus semen assessed as having normal parameters according to the World Health Organization 2010 criteria were used to perform the HSMAs. First, each consumable was tested individually. Then, associations of three, four, and five consumables, previously validated as non-toxic when tested individually, were analyzed. HSMAs were conducted three times to ensure reproducibility, with a defined toxicity threshold of a sperm motility index (SMI) below 0.85 in at least two of three tests. MAIN RESULTS AND THE ROLE OF CHANCE: Thirty-six references of disposables were first individually tested across 53 lots. Forty-nine (92%) demonstrated compliance. However, four (8%) devices revealed toxicity: one lot of 1 ml syringes, two lots of sperm cups, and one lot of 25 cm2 flasks. These four references were excluded from the IVF routine procedures. A total of 48 combinations of consumables were assessed, involving 41 lots from 32 references that were previously individually tested. Among the evaluated combinations, 17 out of 48 (35%) associations exhibited toxicity with a SMI below 0.85 for two of the three tests (n = 8) or all the three tests (n = 9). Notably, three out of 17 (18%) of the three-consumable associations, five out of 16 (31%) of the four-consumable associations, and nine out of 15 (60%) of the five-consumable associations were found not compliant. The toxicity did not originate from a single consumable, because only consumables that were individually pre-validated as non-toxic were included in the combinations, but the toxicity had a cumulative origin. The risk of cumulative toxicity increased with the number of consumables included in the association (Cochran-Mantel-Haenszel statistic, P = 0.013). LIMITATIONS, REASONS FOR CAUTION: The high proportion of non-compliant combinations of disposables can be attributed directly to the extreme rigorous extraction conditions employed during the tests, which could deviate from the conditions encountered in routine clinical use. Also, the methodology employed in the HSMAs (e.g. toxicity extraction duration, sperm concentrations, and protein supplementation of the medium) can influence the sensitivity of the tests. WIDER IMPLICATIONS OF THE FINDINGS: This study highlights the significance of performing toxicity testing on devices before introducing them into clinical practice. Disposables should be tested individually to detect immediate toxicities and also in combination. Our results advocate rationalizing the number of consumables used in each IVF procedure and re-evaluating the use of glass consumables. STUDY FUNDING/COMPETING INTEREST(S): This study received fundings from GCS Ramsay Santé pour l'Enseignement et la Recherche (Paris, France) and the Centre de Biologie Médicale BIOGROUP (Le Chesnay-Rocquencourt, France). The authors declare that they have no conflict of interest that could be perceived as prejudicing the impartiality of the reported research. TRIAL REGISTRATION NUMBER: N/A.

KPC-2 allelic variants in Klebsiella pneumoniae isolates resistant to ceftazidime-avibactam from Argentina: blaKPC-80, blaKPC-81, blaKPC-96 and blaKPC-97.

Ceftazidime-avibactam (CZA) therapy has significantly improved survival rates for patients infected by carbapenem-resistant bacteria, including KPC producers. However, resistance to CZA is a growing concern, attributed to multiple mechanisms. In this study, we characterized four clinical CZA-resistant Klebsiella pneumoniae isolates obtained between July 2019 and December 2020. These isolates expressed novel allelic variants of blaKPC-2 resulting from changes in hotspots of the mature protein, particularly in loops surrounding the active site of KPC. Notably, KPC-80 had an K269_D270insPNK mutation near the Lys270-loop, KPC-81 had a del_I173 mutation within the Ω-loop, KPC-96 showed a Y241N substitution within the Val240-loop and KPC-97 had an V277_I278insNSEAV mutation within the Lys270-loop. Three of the four isolates exhibited low-level resistance to imipenem (4 µg/mL), while all remained susceptible to meropenem. Avibactam and relebactam effectively restored carbapenem susceptibility in resistant isolates. Cloning mutant blaKPC genes into pMBLe increased imipenem MICs in recipient Escherichia coli TOP10 for blaKPC-80, blaKPC-96, and blaKPC-97 by two dilutions; again, these MICs were restored by avibactam and relebactam. Frameshift mutations disrupted ompK35 in three isolates. Additional resistance genes, including blaTEM-1, blaOXA-18 and blaOXA-1, were also identified. Interestingly, three isolates belonged to clonal complex 11 (ST258 and ST11) and one to ST629. This study highlights the emergence of CZA resistance including unique allelic variants of blaKPC-2 and impermeability. Comprehensive epidemiological surveillance and in-depth molecular studies are imperative for understanding and monitoring these complex resistance mechanisms, crucial for effective antimicrobial treatment strategies. IMPORTANCE: The emergence of ceftazidime-avibactam (CZA) resistance poses a significant threat to the efficacy of this life-saving therapy against carbapenem-resistant bacteria, particularly Klebsiella pneumoniae-producing KPC enzymes. This study investigates four clinical isolates exhibiting resistance to CZA, revealing novel allelic variants of the key resistance gene, blaKPC-2. The mutations identified in hotspots surrounding the active site of KPC, such as K269_D270insPNK, del_I173, Y241N and V277_I278insNSEAV, prove the adaptability of these pathogens. Intriguingly, low-level resistance to imipenem and disruptions in porin genes were observed, emphasizing the complexity of the resistance mechanisms. Interestingly, three of four isolates belonged to clonal complex 11. This research not only sheds light on the clinical significance of CZA resistance but also shows the urgency for comprehensive surveillance and molecular studies to inform effective antimicrobial treatment strategies in the face of evolving bacterial resistance.

Exploration and Practice of the "One Combination, Two Highlights, Three Combinations, Four in One" Innovative Talents Training Mode in Forensic Medicine.

Talent is one of the basic and strategic supports for building a modern socialist country in all aspects. Since the 1980s, the establishment of forensic medicine major and the cultivation of innovative talents in forensic medicine have become hot topics in higher education in forensic medicine. Over the past 43 years, the forensic medicine team of Shanxi Medical University has adhered to the joint education of public security and colleges, and made collaborative innovation, forming a training mode of "One Combination, Two Highlights, Three Combinations, Four in One" for innovative talents in forensic medicine. It has carried out "5+3/X" integrated reform, and formed a relatively complete talent training innovation mode and management system in teaching, scientific research, identification, major, discipline, team, platform and cultural construction. It has made a historic contribution to China's higher forensic education, accumulated valuable experience for the construction of first-class major and first-class discipline of forensic medicine, and provided strong support for the construction of the national new forensic talent training system. The popularization of this training mode is conducive to the rapid and sustainable development of forensic science, and provides more excellent forensic talents for national building, regional social development and the discipline construction of forensic science.

Plasmodium falciparum kelch13 polymorphisms identified after treatment failure with artemisinin-based combination therapy in Niger.

BACKGROUND: Artemisinin-based combination therapy (ACT) is the most effective treatment for malaria, and has significantly reduced morbimortality. Polymorphisms associated with the Plasmodium falciparum Kelch gene (Pfkelch13) have been associated with delayed parasite clearance even with ACT treatment. METHODS: The Pfkelch13 gene was sequenced from P. falciparum infected patients (n = 159) with uncomplicated malaria in Niger. An adequate clinical and parasitological response (ACPR) was reported in 155 patients. Four (n = 4) patients had treatment failure (TF) that were not reinfections-two of which had late parasitological failures (LPF) and two had late clinical failures (LCF). RESULTS: Thirteen single nucleotide polymorphisms (SNPs) were identified of which seven were non-synonymous (C469R, T508S, R515T, A578S, I465V, I437V, F506L,), and three were synonymous (P443P, P715P, L514L). Three SNP (C469R, F506L, P715P) were present before ACT treatment, while seven mutations (C469R, T508S, R515T, L514L, P443P, I437V, I465V) were selected by artemether/lumefantrine (AL)-five of which were non-synonymous (C469R, T508S, R515T, I437V, I465V). Artesunate/amodiaquine (ASAQ) has selected any mutation. One sample presented three cumulatively non-synonymous SNPs-C469R, T508S, R515T. CONCLUSIONS: This study demonstrates intra-host selection of Pfkelch13 gene by AL. The study highlights the importance of LCF and LPF parasites in the selection of resistance to ACT. Further studies using gene editing are required to confirm the potential implication of resistance to ACT with the most common R515T and T508S mutations. It would also be important to elucidate the role of cumulative mutations.

Exploration and Practice of the "One Combination, Two Highlights, Three Combinations, Four in One" Innovative Talents Training Mode in Forensic Medicine / 法医学杂志

Talent is one of the basic and strategic supports for building a modern socialist country in all aspects. Since the 1980s, the establishment of forensic medicine major and the cultivation of innovative talents in forensic medicine have become hot topics in higher education in forensic medicine. Over the past 43 years, the forensic medicine team of Shanxi Medical University has adhered to the joint education of public security and colleges, and made collaborative innovation, forming a training mode of "One Combination, Two Highlights, Three Combinations, Four in One" for innovative talents in forensic medicine. It has carried out "5+3/X" integrated reform, and formed a relatively complete talent training innovation mode and management system in teaching, scientific research, identification, major, discipline, team, platform and cultural construction. It has made a historic contribution to China's higher forensic education, accumulated valuable experience for the construction of first-class major and first-class discipline of forensic medicine, and provided strong support for the construction of the national new forensic talent training system. The popularization of this training mode is conducive to the rapid and sustainable development of forensic science, and provides more excellent forensic talents for national building, regional social development and the discipline construction of forensic science.

Public sector reforms and their impact on the level of corruption: A systematic review.

Background: In spite of the large number of anti-corruption reforms implemented in different countries, there has been little research that empirically and systematically assesses the impact of these efforts. Objectives: The main objective of this review is to identify what works in curbing corruption in the public sector, by meta-analyzing the findings of published and unpublished evaluations of different types of anti-corruption interventions in different countries. The focus of this review is administrative corruption, namely corrupt acts involving civil servants in their dealings with their superiors, during the implementation of public policies, or while interacting with the public for service delivery. Political corruption (in the adoption of laws, regulations, and policies), and private-to-private corruption (involving only private actors) are excluded from this review. Search methods: The literature search was conducted by querying three widely recognized electronic databases: RePEc, SSRN, and Web of Science. These databases are considered the most comprehensive in the socio-economic field of research. The main grey literature repositories were also queried. Both published and unpublished studies were searched on the basis of specific combinations of keywords. The terms used to define queries were based on the "types of corruption", "types of interventions/policies/reforms" and "study design" search strings. Specific conventions were used to "explode" or "truncate" keywords as appropriate. Screening of the references (i.e., snowballing) of the identified studies was also performed, and a reverse snowballing approach on Google Scholar was used. In order to ensure replicability, all searches were stored into Covidence, an online software developed by the Cochrane community for screening studies and extracting data for systematic reviews. Selection criteria: Any study that included experimental evaluations (randomized controlled trials) of interventions developed for use in the public sector (e.g., public administration, education, health, etc.) to curb administrative corruption has been included in this review without any geographical or temporal limitations. Only studies written in or translated into English have been considered. Data collection and analysis: Two review authors read the titles and abstracts of identified studies in order to determine their eligibility against the inclusion/exclusion criteria. When a title or abstract could not be included or rejected with certainty, the full text of the article was reviewed. In case of disagreement about whether or not a study should be included, the lead author (Giulia Mugellini), together with Martin Killias acted as arbitrator. The relevant information from identified studies was extracted independently by two review authors, following the guidelines of the Campbell Collaboration. The studies were assessed using the Cochrane Risk of Bias checklist as a basis.The effect size selected for the analysis was the Fisher's z-score transformation of the partial correlation coefficient. For the meta-analysis, random effect(s) models were estimated. Meta-regression analysis models were then used to investigate the determinants behind the observed between- and within-study heterogeneity. Ten different covariates were included in the meta-regression models in order to control for the type of intervention, the type of corruption, the level of national income, the quality of the study and the type of participants involved in laboratory experiments. Results: The initial literature search led to the identification of 70 studies. Approximately one-third of the studies were excluded at the title/abstract stage because they either did not evaluate any anti-corruption intervention but simply assessed the relationship between corruption and other phenomena, or because the study design was not based on randomized controlled trials. Another 14 studies were excluded only after a full-text assessment. At this stage, the main reasons for exclusion were related to an unsuitable type of corruption (e.g., when the focus of the paper was political corruption, or private-to-private corruption instead of administrative corruption), the lack of regression output, or an unsuitable study design. At the end of the selection process, 29 studies resulted as eligible for inclusion.All the selected studies were written in English. The publication years ranged from 2007 to 2018. The majority of the selected studies (20) investigates the effect of anti-corruption interventions in high- and upper-middle income countries (Austria, Brazil, Canada, China, Germany, Italy, Mexico, the Netherlands, Thailand, the United Kingdom, and the United States). Nine studies focused on low- and low-middle income countries (Burkina Faso, Burundi, Ethiopia, India, Indonesia, Pakistan, Tanzania, and Uganda). All of them were randomized experiments. Twenty-five of these experiments were conducted in a laboratory, while four of them were field experiments.As to the type of outcome, the majority (18) of the selected studies addressed bribery (either active or passive), while 11 studies considered misappropriation of public resources (embezzlement). In terms of anti-corruption interventions, 19 studies tested the effect of deterrence interventions, while 10 studies focused on policies based on organizational and cultural change.Overall, the meta-analysis' findings indicate that the identified interventions decrease the level of corruption. Results are statistically significant (p < 0.01) and robust to different heterogeneity estimators-that is, (restricted) maximum likelihood and method of moment estimators. The observed high level of heterogeneity- I 2 is equal to 92.36%, of which 43.78% is due to between-study heterogeneity and 48.57% to within-study heterogeneity-albeit in line with other meta-analyses in economics, suggests the need for meta-regression analyses.To investigate the determinants behind the between- and within-study heterogeneity of the observed effect, both a random effect model and a multilevel model were adopted.The results of the multilevel model show that: 1)Control and deterrence interventions are more effective than organizational and cultural reforms in reducing corruption in the public sector.2)Combining different interventions reduces corruption more than single interventions.3)Interventions are more effective in preventing misappropriation of public resources (embezzlement) than passive or active bribery. Finally, the Funnel Asymmetry Test (FAT), conducted with both additive and multiplicative dispersion terms, shows no evidence of a strong publication bias in the literature. Authors' conclusions: The results of this systematic review, based on a combination of laboratory and field experiments, demonstrate that increasing the expected monetary costs (e.g., sanctions) of corruption or the probability of detection (e.g., audit risk) is more effective than organizational, cultural and educational interventions in curbing administrative corruption, at least in the short term. However, this result might be due to the fact that the majority of selected studies are based on lab-experiments, where the assessment of the intervention is almost concurrent to its development. Short-term evaluations might fail to identify the effect of organizational and cultural interventions. Indeed, these interventions are based on structural changes in the organization of the system and the ethical and cultural education of public officials and might, thus, entail long periods to display their results on the level of corruption. Nevertheless, a combination of different interventions proves to be more effective than single interventions. For example, policies guaranteeing impunity to officials or citizens who report corrupt practices (principal witness/leniency treatment) are more effective if associated with a high probability of audit than leniency alone. A low probability of detection can be compensated by the threat of high fines in reducing both the amount and the likelihood of bribe demands. To the contrary, a high probability of detection had no effect in the absence of severe sanction threats.The importance of the organizational and cultural environment in which the intervention is implemented clearly emerged in the literature. When possible, the characteristics of the settings where the interventions were developed were included in the meta-regression analysis (such as the level of income of the countries). When it was not possible to measure contextual factors and their interaction with the main intervention, a qualitative analysis was performed to reveal the complexities of these interactions.This additional analysis shows that the impact of the interventions was found to be affected by the likelihood of the continued interactions between bribe takers and givers, the amount and probability of fines, and the size of the bribe, among others. For example, reporting mechanisms and leniency policies increase their potential in combination with interventions that limit agent's exposure to one another - such as staff rotation. The success of audit risk on corruption is strongly dependent on the seriousness of the potential sanction and the probability that a sanction is applied. Some differences also emerge between high- and low-corruption countries regarding the effectiveness of anti-corruption interventions. For example, measures tending to increase social blame of corrupt practices work in low-corruption countries. Adding punishments in environments where actors' behavior is tightly monitored increases compliance, but more so in environments where corruption is the exception rather than the rule.In terms of implications for research, the fact that control and deterrence turns out to be more effective than organizational andcultural interventions in curbing administrative corruption confirms the importance of economic theories (and cost-benefit analysis). However, the meta-analysis also demonstrates the effectiveness of combining different types of interventions.This is true not only when combining policies reinforcing control and deterrence (monitoring frequency, detection probability and amount of fines), but also when policies based on organizational and cultural change are added (e.g., staff rotation and leniency). In particular, the role of moral levers in preventing corruption emerges, and especially the importance of strengthening professional identity and values in order to avoid conflicts between an individual's private interests and his/her public role. These results highlight the importance of going beyond economic models for explaining corruption, and considering the moral and cultural mechanisms underlying this phenomenon.It also emerges the need to understand how different forms of corruption operate in practice at macro- (cross-country), meso- (country/nation-state) and micro- (individual) level. In particular, individual-level factors, such as the strive for power, low self-control, loss aversion and risk acceptance would need to be addressed.It would be interesting to distinguish, when more experimental studies will be available, between top-down (from supervisors to officials) and bottom-up (from citizens to officials) interventions.From a methodological point of view, it could be tested whether the results change according to the types of games used as a basis for the corruption experiments (e.g., behavioral game theory, trust game, etc.) and according to the setting in which the experiment was conducted (e.g., context-free versus in-context presentation of experimental tasks).Considering the effect of sensitization messages in reducing bribery demand, we would encourage researchers to develop other corruption experiments that explore the impact of interventions in fostering professional self-identity, as well as the impact of organizational family culture on corruption. Furthermore, this review highlights the need for a comprehensive classification of anti-corruption policies that distinguishes interventions by type of corruption, risk factors, type of policy tool and administrative sector.

The in vitro antimicrobial evaluation of commercially essential oils and their combinations against acne.

OBJECTIVE: The study investigated the efficacy of commercial essential oil combinations against the two pathogens responsible for acne with the aim to identify synergy and favourable oils to possibly use in a blend. MATERIALS AND METHODS: Antimicrobial activity was assessed using the minimum inhibitory concentration (MIC) assay against Staphylococcus epidermidis (ATCC 2223) and Propionibacterium acnes (ATCC 11827), and the fractional inhibitory concentration index (ΣFIC) was calculated. Combinations displaying synergistic interactions were further investigated at varied ratios and the results plotted on isobolograms. RESULTS: From the 408 combinations investigated, 167 combinations were identified as displaying noteworthy antimicrobial activity (MIC value ≤1.00 mg mL-1 ). Thirteen synergistic interactions were observed against S. epidermidis, and three synergistic combinations were observed against P. acnes. It was found that not one of the synergistic interactions identified were based on the combinations recommended in the layman's aroma-therapeutic literature. Synergy was evident rather from leads based on antimicrobial activity from previous studies, thus emphasizing the importance of scientific validation. Leptospermum scoparium J.R.Forst. and G.Forst (manuka) was the essential oil mostly involved in synergistic interactions (four) against S. epidermidis. Cananga odorata (Lam.) Hook.f. and Thomson (ylang ylang) essential oil was also frequently involved in synergy where synergistic interactions could be observed against both pathogens. The combination with the lowest MIC value against both acne pathogens was Vetiveria zizanioides Stapf (vetiver) with Cinnamomum verum J.Presl (cinnamon bark) (MIC values 0.19-0.25 mg mL-1 ). Pogostemon patchouli Benth. (patchouli), V. zizanioides, C. verum and Santalum spp. (sandalwood) could be identified as the oils that contributed the most noteworthy antimicrobial activity towards the combinations. The different chemotypes of the essential oils used in the combinations predominantly resulted in similar antimicrobial activity. CONCLUSIONS: The investigated essential oil combinations resulted in at least 50% of the combinations displaying noteworthy antimicrobial activity. Most of the synergistic interactions do not necessarily correspond to the recommended layman's aroma-therapeutic literature, which highlights a need for scientific validation of essential oil antimicrobial activity. No antagonism was observed.

Clustering of cardio metabolic risk factors in Iranian adult population: A growing problem in the north of Iran.

INTRODUCTION: The clustering of components of metabolic syndrome (MetS) is a major concern in a transition population because of dramatic changing toward modern life styles. The objective of this study was to determine the prevalence of clustering of various combinations of MetS and its association with obesity. METHODS AND SUBJECTS: In a population- based cross-sectional study, a representative samples of 1000 adults were recruited in Babol, the north of Iran. The demographic data, blood pressure, body mass index and waist circumference (WC) were measured with standard method. Fasting blood sugar, serum levels of triglycerides, high density lipoprotein were measured with enzymatic method. RESULTS: A quarter of population had only one component of MetS. The prevalence of just two components was 30.7% and 26.2% in men and women respectively and about 67.1% of men and 73.3% of women had ≥2 risk factors (P=0.001). While the joint prevalence of three and four components was 22.0% and 12.0% in male and 27.3% and 16.5% in female respectively. The combination of high WC with any of other four components of MetS were significantly higher compared with any other joint combinations in particularly among women (P=0.001). The adjusted odds ratio for having clustering (≥2 risk factors) increased 5.6 times (95%CI: 2.15, 6.04) in obese subjects and remained at significant level after adjustment for age, sex, level of education. CONCLUSION: An emerging high rate of clustering of joint combination of cardio metabolic risk factors highlights an urgent intervention for life style modification in public health management.

Characterization of Salmonella enterica and detection of the virulence genes specific to diarrheagenic Escherichia coli from poultry carcasses in Ouagadougou, Burkina Faso.

One hundred chicken carcasses purchased from three markets selling poultry in Ouagadougou, Burkina Faso, between June 2010 and October 2010 were examined for their microbiological quality. The presence of Salmonella was investigated using standard bacteriological procedures, and the isolates obtained were serotyped and tested for antimicrobial susceptibility. The presence of virulence-associated genes of the five main pathogroups of diarrheagenic Escherichia coli-Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli, and enteroinvasive E. coli-was investigated using 16-plex polymerase chain reaction (PCR) on the mixed bacterial cultures from the poultry samples. Of the 100 chicken carcasses studied, 57 were contaminated by Salmonella; 16 different serotypes were identified, the most frequent being Salmonella Derby, found in 28 samples. Four Salmonella strains were resistant to tetracycline, and two were resistant to streptomycin. Based on the PCR detection of the virulence genes, in total, 45 carcasses were contaminated by three pathogroups of E. coli: STEC, EPEC, or EAEC. The STEC and EPEC virulence genes were detected on six and 39 carcasses, respectively. EAEC virulence genes were only detected in combination with those of EPEC (on 11 carcasses) or STEC (on two carcasses). The STEC-positive carcasses contained the genes stx(1), stx(2), eaeA, escV, and ent in different combinations. None of the EPEC-positive carcasses contained the bfp gene, indicating that only atypical EPEC was present. EAEC virulence genes detected were aggR and/or pic. The high proportion of chicken carcasses contaminated by Salmonella and diarrheagenic E. coli indicates a potential food safety risk for consumers and highlights the necessity of public awareness of these pathogens.

Non-haematological toxicity limiting the application of sequential high dose chemotherapy in patients with advanced breast cancer.

A programme of repeated high dose chemotherapy for advanced breast cancer was developed using (1) cyclophosphamide 4 g/m2 followed by autologous peripheral blood stem cell (PBSC) collection; (2) three cycles of conventional dose chemotherapy; (3) high dose cyclophosphamide, cisplatin, and carmustine with PBSC rescue; and (4) high dose etoposide and melphalan with PBSC rescue. Fifteen eligible patients had advanced poor prognosis breast cancer either at initial diagnosis (one patient) or at relapse (14 patients). During the course of the protocol, there were three treatment related deaths, two patient withdrawals due to debilitating toxicity, five patient withdrawals due to disease progression, and one patient withdrawal due to inadequate collection of PBSC. The remaining four patients did not complete the planned protocol as the programme was terminated because of the unacceptable morbidity and mortality. They were treated with an alternative high dose chemotherapy protocol which was well tolerated. This study highlights the significant problems associated with a complex sequential high dose chemotherapy regimen. Cyclophosphamide mobilized PBSC infused following high dose chemotherapy enables rapid haematological recovery. However the non-haematological toxicity following high dose chemotherapy regimens is often severe and may limit the application of certain sequential high dose chemotherapy combinations in patients with breast cancer.