Patients with brain injuries are at a heightened susceptibility to bacterial pneumonia, and the timely initiation of empiric antibiotic treatment has been shown to substantially reduce mortality rates. Nevertheless, there is a need for knowledge regarding the resistance and prevalence of pulmonary bacterial infections in this patient population. To address this gap, a retrospective study was conducted at a neurosurgical emergency center, focusing on patients with brain injuries. Among the entire patient population, a total of 739 individuals (18.23%) were identified as having bacterial pneumonia, consisting of 1489 strains of Gram-negative bacteria and 205 strains of Gram-positive bacteria. The resistance of Klebsiella pneumoniae to imipenem exhibited a significant increase, rising from 21.74% in 2009 to 96.67% in 2018, and subsequently reaching 48.47% in 2021. Acinetobacter baumannii displayed resistance rates exceeding 80.0% against multiple antibiotics. The resistance profile of Pseudomonas aeruginosa was relatively low. The proportion of Staphylococcus aureus reached its peak at 18.70% in 2016, but experienced a decline to 7.83% in 2021. The abundance of Gram-negative bacteria exceeded that of Gram-positive bacteria by a factor of 5.96. Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus are prominent pathogens characterized by limited antibiotic choices and scarce treatment alternatives for the isolated strains.

In the last years, there has been an increase of antimicrobial resistance rates around the world with the misuse and overuse of antimicrobials as one of the main leading drivers. In response to this threat, a variety of initiatives have arisen to promote the efficient use of antimicrobials. These initiatives rely on antimicrobial surveillance systems to promote appropriate prescription practices and are provided by national or global health care institutions with limited consideration of the variations within hospitals. As a consequence, physicians\' adherence to these generic guidelines is still limited. To fill this gap, this work presents an automated approach to performing local antimicrobial surveillance from microbiology data. Moreover, in addition to the commonly reported resistance rates, this work estimates secular resistance trends through regression analysis to provide a single value that effectively communicates the resistance trend to a wider audience. The methods considered for trend estimation were ordinary least squares regression, weighted least squares regression with weights inversely proportional to the number of microbiology records available and autoregressive integrated moving average. Among these, weighted least squares regression was found to be the most robust against changes in the granularity of the time series and presented the best performance. To validate the results, three case studies have been thoroughly compared with the existing literature: (i) Escherichia coli in urine cultures; (ii) Escherichia coli in blood cultures; and (iii) Staphylococcus aureus in wound cultures. The benefits of providing local rather than general antimicrobial surveillance data of a higher quality is two fold. Firstly, it has the potential to stimulate engagement among physicians to strengthen their knowledge and awareness on antimicrobial resistance which might encourage prescribers to change their prescription habits more willingly. Moreover, it provides fundamental knowledge to the wide range of stakeholders to revise and potentially tailor existing guidelines to the specific needs of each hospital.

In response to the global increase in antibiotic resistance, the concept of antibiotic stewardship (ABS) has become increasingly important in recent years. Several publications have demonstrated the effectiveness of ABS, mainly in university facilities. This retrospective observational study describes the implementation of ABS in a basic care hospital.
Following existing national guidelines, an ABS team was set up and measures were launched. These included: hospital guidelines, teaching, weekly antibiotic ward rounds and the restriction of definite substances. The preinterventional/postinterventional data analysis compared the use of antibiotics and blood culture sets as well as the development of resistance, infection with Clostridium difficile (CDI), costs, mortality and length of hospital stay.
The measures introduced led to a significant and continuous decline in total antibiotic use of initially 43 recommended daily doses (RDD)/100 patient days (PD) to 31 RDD/100 PD (p < 0.001). The largest decrease was observed in second generation (2G) cephalosporins (-67.5%), followed by 3G cephalosporins (-52.7%), carbapenems (-42.0%) and quinolones (-38.5%). The resistance rate of E. coli to 3G cephalosporins in blood cultures decreased from 26% to 9% (p = 0.021). The rate of blood cultures taken increased from 1.8 sets/100 PD to 3.2 sets/100 PD (+77%, p < 0.001). The pathogen detection rate, defined as one count when a minimum of one sample taken in a day is positive, also increased significantly from 4.0/1000 PD to 6.8/1000 PD (p < 0.001). The ABS had no effect on the overall mortality, the mean dwell time, and the preintervention low CDI incidence.
The preinterventional/postinterventional comparison showed a significant reduction in the overall consumption of antibiotics with a redistribution in favor of antibiotics with a lower resistance selection. At the same time, the resistance rate of E. coli decreased. The increase of the blood culture rate indicates the optimization of diagnostic procedures. This ABS program had to be established with reduced resources but this seems to have been compensated by the more personal contact addressing the care takers and short chain of commands, as is possible in smaller hospitals. Presumably, the structure of basic care hospitals is particularly suitable for concepts covering entire hospitals. Further clusters of randomized studies are necessary to confirm this.