Phenoxymethylpenicillin Research Articles

Risk factors associated with Cryptosporidia, Eimeria, and diarrhea in smallholder dairy farms in Mukurwe-ini Sub-County, Nyeri County, Kenya.

Aim:This study was undertaken to determine the household, calf management, and calf factors associated with the occurrence of Eimeria, Cryptosporidia, and diarrhea in pre-weaned calves reared in smallholder dairy farms in Mukurwe-ini Sub-County of Nyeri County, Kenya. In addition, the study also evaluated factors associated with average daily weight gain in the same pre-weaned calves.Materials and Methods:A total of 112 newborn calves (63 males and 49 females) on 111 farms (1 set of twins) were followed for 2 months between June 2013 and August 2013. Two calves were lost to follow-up. A pre-tested questionnaire was used to collect data on household characteristics and calf management practices in the 111 selected farms. On the first visit to the farm (within 7 days of the birth of the calf), blood samples were collected from the jugular vein to assess the level of maternal immunity acquired by the calf, by determining the serum total protein and selenium concentration. At 4 and 6 weeks of age, fecal samples from the calves were collected to assess the presence of Cryptosporidia and Eimeria oocysts. Every 2 weeks for 2 months, the calves and their environments were examined, their 2-week consumption and health history were recorded, and weights were estimated with a weight tape. Each of the factors was evaluated in a univariable regression model and only those found to be significant (p≤0.20) were included in a multivariable model. Elimination of non-significant factors was done in the multivariable model through a backward elimination procedure so that only those variables which were confounders, and/or significant at (p≤0.05) remained in the final model.Results:About 37% (41/110) of the calves experienced diarrhea at least once during the 2-month study period. The overall period prevalence of Eimeria and Cryptosporidia was 42.7% (47/110) and 13.6% (15/110), respectively. Low serum protein was associated with 1.8 and 2.4 times the odds of Eimeria and Cryptosporidia infections, respectively. Lack of supervision of calf birth and low serum total protein were both associated with 1.3 times the odds of diarrhea incidence. Dirty calf pens, feeding <5 L of milk/day, and infection with Eimeria were associated with 0.105, 0.087, and 0.059 kg, respectively, reduced average daily weight gain of the calves.Conclusion:In the Kenyan context, calf diarrhea risk could be reduced through better supervision of parturition and colostrum provision. Specifically, the risk of Eimeria and Cryptosporidia infections could be reduced by optimizing the passive transfer of immunity to the newborn calves. Average weight gains of calves could be improved by good colostrum provision, pen hygiene, and preventing Eimeria infections.

Short communication: Effect of diet changes on sorting behavior of weaned dairy calves

Dairy cows sort mixed rations; in some cases sorting can lead to digestive disorders. How sorting behavior develops in calves is poorly understood. The objective of this observational study was to determine if sorting behavior of total mixed ration (TMR)-fed dairy calves was affected by the removal of supplementary concentrate. Dairy bull calves (n=18) were provided access to both a TMR (49.1% dry matter) and calf starter fed separately during the preweaning period starting at 3 d of age. Sorting of the TMR was assessed after weaning when calves were provided both feeds at 65 d of age, and again at 70 d immediately following the removal of calf starter from the calf pen. Sorting was measured by comparing the particle size composition of the TMR offered with that of the orts following 24h of feed access. Feed particle fractions were measured using the Penn State Particle Separator with 3 screens (19, 8, and 1.18mm) and a bottom pan to separate the TMR into long, medium, short, and fine fractions, respectively. At d 65, calves sorted for long particles (133±9%) and against small particles (92±3%), with no differences for the remaining fractions (99±5% for medium; 107±5% for fine); these preferences were reversed at d 70 when calf starter was no longer available with calves preferentially selecting fine particles (113±4%), but showing no preference for other fractions (101±11% for long; 99±6% for medium; 97±4% for short). These results indicate that young dairy calves are capable of sorting a TMR and they adjust this behavior in response to the availability of grain.

Amoxicillin for the secondary prevention of rheumatic fever in children not allergic to penicillin

Amoxicillin for the secondary prevention of rheumatic fever in children not allergic to penicillin To the Editor: In October 2014, a communication from the Department of Health substituted azithromycin for erythromycin for penicillin-allergic patients. This was for certain conditions including acute rheumatic fever and prophylaxis of rheumatic fever. It has recently been suggested that owing to the challenges with the availability of oral penicillin, azithromycin should be used as a penicillin substitute for patients who are not allergic to penicillin. In our opinion it is inappropriate to substitute a macrolide for another form of penicillin (amoxicillin) in this situation. The primary reason is that despite many decades of use, there is no significant group A beta-haemolytic streptococcal (GABHS) resistance to penicillin. There are, however, increasing reports of GABHS resistance to macrolides, and azithromycin in particular.[1-4] A previously reported randomised trial[5] of 125 mg phenoxymethylpenicillin (pen VK) or amoxicillin given three times a day for 10 days to children with GABHS pharyngitis demonstrated that the recurrence of the original GABHS within 21 days after the end of therapy was higher with pen VK (20%) than with amoxicillin (13%). The geometric mean minimum inhibitory concentrations for amoxicillin and pen VK against 88 isolates of GABHS were 0.008 and 0.009 μg/mL, respectively. The mean concentrations of amoxicillin and pen VK in sera after 125 mg doses were 3.86 μg/ mL and 1.74 μg/ mL, respectively. In this study, therefore, amoxicillin was active against Gram-positive organisms at an inhibitory level similar to that of pen VK, but had higher blood levels. This study suggests that amoxicillin is probably at least as good as pen VK for the treatment of GABHS pharyngitis. We therefore recommend, as per the South African Essential Drugs List, benzathine penicillin 600 000 units for children <30 kg and 1.2 million units for children ≥30 kg by intramuscular injection every 28 days for the secondary prevention of rheumatic fever. If it is not advisable to use an intramuscular form of penicillin (for example with a patient on warfarin), then in the absence of pen VK and in the absence of penicillin allergy, children weighing <20 kg should be given amoxicillin 125 mg twice daily, and children weighing ≥20 kg given 250 mg twice daily. There is no defined azithromycin paediatric dosage for the secondary prevention of rheumatic fever in penicillin allergy. Azithromycin has however been dosed long term in clinical trials in children with cystic fibrosis.[6-8] There is no consensus on the dosage, but there is some support[6-9] for 250 mg once daily (<40 kg) or 500 mg once daily (≥40 kg) three times a week (Monday, Wednesday and Friday). We recommend that azithromycin is used for the secondary prevention of rheumatic fever only in children who are allergic to penicillin and is dosed 250 mg (<40 kg) or 500 mg (≥40 kg), once a day three times a week (Monday, Wednesday and Friday).

Bovine Coronavirus (BoCV) Infection in Calves with Diarrhoea and Their Dams

Background: Bovine coronavirus (BoCV) is common with high seroprevalence in dairy cattle. It is reported in many countries. Also, BoCV causes diarrhea in dairy calves. The transmission of BoCV is the fecal-oral/aerosol-nasal routes. Feces from clinical cases or clinically normal dairy cattle are source of infection, also contamination of feed and water. The purpose of the current study was to investigate BoCV infection in diarrheic calves (age and sex) and their dams (age). For this reason, the serological and virological methods were used. Haematological parameters of the calves and their dams were compared using the statistical methods.Materials, Methods &amp; Results: In this study, following clinical examination of 3500 cattle and their calves from 25 number of dairy farms 184 calves with diarrhoea and their dams (183) (≥2 - ≤6 age) were sampled for BoCV presence by enzyme linked immunosorbent assay (ELISA). Additionally, all blood samples were examined by hematological methods. 172 (93.99%) cows and 172 (93.99%) calves were found antibodies (Ab) positive (+). The high levels of Ab for BoCV were detected as 36.05 % in dams 6 years and older ages. In the calves, Ab to BoCV were found at the highest level (25.26%) in the female calves ≥5 - ≤6 months ages. BoCV antigen (Ag) was detected in only faecal sample of a (0.54%) calf. When the haematological parameters were compared between BoCV Ab (+) and BoCV Ab negative (-) dams, only white blood cell (WBC) values were found statistically significant (P &lt; 0.05). When the haematological parameters were compared between BoCV Ab (+)/Ag (-) and BoCV Ab (-)/Ag (-) calves, WBC (P &lt; 0.05), lymphocyte (P &lt; 0.01) and granulocyte (P &lt; 0.01) values were found statistically important. When the haematological parameters were compared between BoCV Ab (+)/Ag (+) and BoCV Ab (-)/Ag (-) calves, both lymphocyte and granulocyte values were statistically important (P &lt; 0.01).Discussion: BoCV infection has found worldwide among cattle of all ages. The disease results in major economic losses in dairy herds that result from treatment costs and calf deaths. One hundred seventy two out of 183 mothers whose blood sampling was done were detected as seropositive. Many researchers found similar results in dairy cattle. It was detected the highest seropositivity in cattle more than six years old. One hundred seventy two blood samples out of 184 calves were detected seropositive. Also, the highest seropositivity was detected among of &gt; 5 and &lt; 6 months of age. BoCV Ag (+) presence was detected in only one faecal sample of one calf out of 184. Researchers were found same or higher BoCV Ag(+) rates in faeces of diarrheic calves. In the study lymphocyte counts of seropositive cows and in Ab(+)/Ag(+) calves determined decrease. However, the counts in seropositive calves were increased. Leukocytes levels were also high in seropositive calves. Haematocrit values were decreased in seropositive cows, calves and in Ab(+)/Ag(-) calves. BoCV infections were detected at low level in diarrheic calves. But, BoCV seropositive mature and diarrheic calves were found at high levels. Haematological application methods could be used to be supportive with the serological and virological methods. All farm managements should be maintained with strict hygiene practices. Milking bottle, calf pens or hutches need to be sanitized. The calves must be prevent contamination from faeces and urine of other calves. The protective vaccination must be applied all animals.

Drug allergy evaluation for betalactam hypersensitivity: Cross-reactivity with cephalosporines, carbapenems and negative predictive value.

There are no studies on cross-reactivity of betalactams among patients allergic to penicillin, or on the negative predictive value (NPV) of penicillin allergy evaluation from Arabian Gulf countries. We aimed to assess the role and NPV of drug provocation test (DPT) for betalactam hypersensitivity reactions in patients referred for allergy evaluation in Kuwait. Skin test (ST) was performed for all patients with a history of betalactam hypersensitivity, other than anaphylaxis. Patients with a negative ST were challenged with a DPT containing phenoxymethyl penicillin or the culprit drug. Patients with anaphylaxis or who tested positive to betalactams were then challenged with a DPT containing cefuroxime, meropenem or ceftriaxone. Patients who tested negative were contacted by phone to evaluate subsequent betalactam intake. A total of 214 patients were tested for betalactam hypersensitivity. We had 91(42.5%) positive cases. Among positives, there were 78 (85.7%) patients with an initial reaction to penicillin and 13 (14.3%) who reacted to cephalosporin. DPT with alternative betalactam was performed in fifty who tested positive for betalactam hypersensitivity and 45 (90%) tolerated alternative antibiotics. Phone calls to 113 (59.8%) patients with negative betalactam testing showed that among 40(35.4%) patients who were successfully contacted; 17 (15%) took betalactams and 23 (20%) did not. Among the 17 patients who took betalactams, our calculated NPV for penicillin testing range from 88.2 to 100%, as the 2 patients who reported a reaction refused confirmatory retesting. Carbapenems and cephalosporines can be safely given to penicillin allergic patients by means of skin testing and if negative, proceeding with a graded challenge. Our calculated NPV for penicillin testing is similar to other studies.

Influence of an early exposure to the calving pen on lying behavior at calving and avoidance distance of dairy heifers

Dairy heifers are confronted with a number of changes in their environment before their first parturition. In this study, we examined the influence of an early exposure to a calving pen 4 weeks prepartum, combined with increased human–animal contact, on behavior around calving and avoidance distance of heifers. Data were collected on 65 Brown Swiss heifers on five Swiss dairy farms. On each farm heifers were randomly assigned to two treatment groups. Thirty-four treated heifers were singly housed for 24h in the calving pen 4 weeks before expected calving, a procedure that also involved handling by a human. Heifers of the control group (n=31) were housed for the first time in the calving pen on the days before and during parturition. Lying behavior was recorded using data loggers, and a human avoidance test involving a familiar and an unfamiliar person was conducted 4 weeks prepartum and 1 week postpartum. Additionally, interventions during parturition were logged. Neither the proportion of time spent lying observed for either 48 or 12h around birth nor the number of lying bouts observed for 48 around birth differed significantly between treated and control heifers (all P>0.20). In the period of 6h before to 6h after calving, the number of lying bouts decreased with number of days that heifers had spent in the calving pen before parturition for the treated heifers and increased for the control heifers (interaction P=0.019). The avoidance distance was higher for the unfamiliar than for the familiar person (P<0.001), tended to decrease from before to after calving (P=0.07), and did not differ between treated and control heifers (P=0.14). There was no significant difference in the risk of an intervention between treated and control heifers (P=0.24). In conclusion, these results do not provide evidence that an early exposure of dairy heifers to the calving pen had a positive effect on their lying behavior around parturition and avoidance distance. However, additional time in the calving pen pre-partum seemed to have a calming effect as reflected by the number of lying bouts in the treated but not the control heifers.

Blistering distal dactylitis in an adult

Streptococci are responsible for a diverse spectrum of cutaneous infections like erysipelas, impetigo, and cellulitis. Blistering distal dactylitis is an infrequent, superficial infection of the anterior fat pad of the distal portion of the finger described classically in children. We report a case of blistering distal dactylitis in an adult caused by group A beta-hemolytic streptococci that was cured with oral phenoxymethyl penicillin. Familiarity with blistering distal dactylitis should permit the dermatologist and internist to diagnose this new entity in adults.

Penicillin V acylase from Pectobacterium atrosepticum exhibits high specific activity and unique kinetics

Penicillin V acylases (PVAs, E.C.3.5.11) belong to the Ntn hydrolase super family of enzymes that catalyze the deacylation of the side chain from phenoxymethyl penicillin (penicillin V). Penicillin acylases find use in the pharmaceutical industry for the production of semi-synthetic antibiotics. PVAs employ the N-terminal cysteine residue as catalytic nucleophile and are structurally and evolutionarily related to bile salt hydrolases (BSHs). Here, we report the cloning and characterization of a PVA enzyme from the Gram-negative plant pathogen, Pectobacterium atrosepticum (PaPVA). The enzyme was cloned and expressed in Escherichia coli attaining a very high yield (250mg/l) and a comparatively high specific activity (430IU/mg). The enzyme showed marginally better pH and thermo-stability over PVAs characterized from Gram-positive bacteria. The enzyme also showed enhanced activity in presence of organic solvents and detergents. The enzyme kinetics turned out to be significantly different from that of previously reported PVAs, displaying positive cooperativity and substrate inhibition. The presence of bile salts had a modulating effect on PaPVA activity. Sequence analysis and characterization reveal the distinctive nature of these enzymes and underscore the need to study PVAs from Gram-negative bacteria.

Cryptosporidium infections in suckler herd beef calves.

A study was carried out to investigate how common Cryptosporidium infections are in beef calves in Swedish suckler herds and to explore which species and subtypes that occur. We further aimed at identifying factors associated with shedding of Cryptosporidium oocysts in this type of calf management. The study was conducted in two regions in Sweden and included 30 herds. Faecal samples were collected from calves younger than 3 months. A brief clinical examination was done and a questionnaire was used to collect data on management routines. Faeces were cleaned and concentrated and oocysts identified by epifuorescence microscopy. Cryptosporidium positive samples were analyzed at the 18S rRNA and GP60 genes to determine species and Cryptosporidium parvum subtype, respectively. Logistic regression was used to identify factors associated with infection. Oocysts were detected in 122 (36.7%) calves from 29 (97%) herds, at 400 to 2.4 × 107 OPG. The youngest positive calves were only 1 and 2 days old. There was no association between age and Cryptosporidium infection. Cryptosporidium bovis, Cryptosporidium ryanae, C. parvum and Cryptosporidium ubiquitum were identified, with C. bovis being the major species. Two C. parvum subtypes, IIaA16G1R1 and IIdA27G1 were identified. Routines for cleaning calf pens and number of cows in calving pens were associated with infection.

Cryptosporidium parvum infections in a cohort of veterinary students in Sweden.

In March 2013, a veterinary student tested positive for Cryptosporidium; four classmates reported similar gastrointestinal symptoms. We aimed to identify source(s) and risk factors for Cryptosporidium infection in university persons symptomatic between 21 January and 14 April 2013. Sixty-four (79%) students from a cohort of 81 fourth-year veterinary students completed questionnaires, identifying 13 cases; four were Cryptosporidium parvum GP60 subtype IIaA16G1R1b, two were IIdA24G1, seven did not submit stool samples. Thirteen cases attended the university's field clinic before symptom onset (13/37 attendees, 35%); 11 visited at least one of four farms where students recalled seeing calves with diarrhoea. C. parvum subtype IIaA16G1R1b was identified in calves at one of the farms. Entering pens of calves with diarrhoea [relative risk (RR) 7·6, 95% confidence interval (CI) 1·7-33·5] and eating in clinic cars (RR 9·1, 95% CI 1·3-65·8) were associated with being a case. Washing hands at least twice per farm visit (0 cases, P = 0·03) was protective. This outbreak investigation was notable for rapid and effective collaboration between public health, veterinary and environmental sectors, leading to swift identification of a microbiological and epidemiological link between cases, infected calves and their farms. We recommend frequent hand-washing using proper technique and dissuasion from eating in clinic cars to minimize possible exposure to contaminated surfaces.

Improving the Effectiveness of Penicillin Allergy De-labeling

Approximately 10-20% of hospitalized patients are labeled as penicillin allergic, and this is associated with significant health and economic costs. We looked at the effectiveness of penicillin allergy de-labeling in clinical practice with the aim of deriving risk stratification models to guide testing strategies. Consecutive patients aged 15 years or more, referred to a Western Australian public hospital drug allergy service between 2008 and 2013 for beta-lactam allergy, were included. Follow-up surveys were conducted. Results of skin prick testing and intradermal testing (SPT/IDT) and oral challenge (OC), and follow-up of post testing antibiotic usage were the main outcomes. SPT/IDT was performed in 401 consecutive patients with immediate (IMM) (≤ 1 hour) (n = 151) and nonimmediate (NIM) (>1 hour) (n = 250) reactions. Of 341 patients, 42 (12.3%) were SPT/IDT+ to ≥ 1 penicillin reagents, including 35/114 (30.4%) in the IMM group and 7/227 (3.1%) in the NIM group (P < .0001). Of 355 SPT/IDT patients, 3 (0.8%), all in the IMM group, had nonserious positive OC reactions to single dose penicillin VK (SPT/IDT negative predictive value [NPV] 99.2%). Selective or unrestricted beta-lactam was recommended in almost 90% overall, including 238/250 (95.2%) in the NIM group and 126/151 (83.4%) in the IMM group (P = .0001). Of 182 patients, 137 (75.3%) were following the allergy label modifications (ALM) at the time of follow-up. Penicillin SPT/IDT/OC safely de-labels penicillin-allergic patients and identifies selective beta-lactam allergies; however, incomplete adherence to ALM recommendations impairs effectiveness. Infrequent SPT/IDT+ and absent OC reactions in patients with NIM reactions suggest OC alone to be a safe and cost-effective de-labeling strategy that could improve the coverage of penicillin allergy de-labeling in lower risk populations.

Systemic antibiotics for symptomatic apical periodontitis and acute apical abscess in adults.

Systemic antibiotics for symptomatic apical periodontitis and acute apical abscess in adults.

Locomotor play of veal calves in an arena: Are effects of feed level and spatial restriction mediated by responses to novelty?

When calves are placed in an open arena, they perform locomotor play, which provides a time-efficient means of assessing playfulness. To use this as a method of assessing welfare, we need to relate playfulness to other welfare indicators and understand what factors influence results. The novelty of the arena, the ages of the calves, and the size of the enclosure relative to the calf's home pen can have important effects. We placed veal calves for 15min in a novel (11m×3.2m) arena and measured the frequency of jumping and the duration of running. To determine whether fearfulness or exploratory behaviour mediates changes in locomotor play, we measured vocalization, defecation, sniffing and latency to enter the arena. In exp. 1, 24 calves were assigned to two feed levels. At about 6 weeks of age, calves on the high feed level did less jumping and running (P<0.05) but there were no differences in sniffing, defecating or latency to enter the arena. Sniffing was correlated (P<0.05) with both jumping (r=0.46) and running (r=0.56) while the latency to enter the arena was negatively correlated (P<0.05) with jumping (r=−0.64) and running (r=−0.58). Defecation was not correlated with either running or jumping. There were no effects of feed level at week 10. In exp. 2, 48 calves were housed either in pens (2.1×1.8m) or in stalls (0.65×1.8m) to examine the effects of spatial restriction. When released into the arena, calves in stalls did more running and jumping than those in pens (P<0.05) with no differences in sniffing, defecating or mooing. When calves in stalls were placed in a pen for 15min before being placed in the arena, there was a reduction in running and jumping which resulted in calves in stalls running less than calves in pens (P<0.05). Running and jumping increased with age, and this was associated with increased sniffing. The effect of novelty and age on locomotor play is mediated by the calves’ levels of exploratory behaviour, with calves that show more exploration doing more play. Among younger calves, fear tends to reduce playfulness, but the effects are not strong. Spatial restriction in the home pen results in a rebound in locomotor play in the arena, which is not related to exploration or fearfulness.

Social Housing Improves Dairy Calves' Performance in Two Cognitive Tests

Early social housing is known to benefit cognitive development in laboratory animals. Pre-weaned dairy calves are typically separated from their dam immediately after birth and housed alone, but no work to date has addressed the effect of individual housing on cognitive performance of these animals. The aim of this study was to determine the effects of individual versus social housing on two measures of cognitive performance: reversal learning and novel object recognition. Holstein calves were either housed individually in a standard calf pen (n = 8) or kept in pairs using a double pen (n = 10). Calves were tested twice daily in a Y-maze starting at 3 weeks of age. Calves were initially trained to discriminate two colours (black and white) until they reached a learning criterion of 80% correct over three consecutive sessions. Training stimuli were then reversed (i.e. the previously rewarded colour was now unrewarded, and vice-versa). Calves from the two treatments showed similar rates of learning in the initial discrimination task, but the individually housed calves showed poorer performance in the reversal task. At 7 weeks of age, calves were tested for their response to a novel object in eight tests over a two-day period. Pair-housed calves showed declining exploration with repeated testing but individually reared calves did not. The results of these experiments provide the first direct evidence that individual housing impairs cognitive performance in dairy calves.

EFFECTS OF SUPPLEMENTAL LYSINE ON PERFORMANCE, ANTIBODY TITER AND RECTAL TEMPERATURE IN RESPONSE TO A MODIFIED-LIVE VIRAL VACCINE IN NEONATAL CALVES

Infectious Bovine Rhinotracheitis (IBR), caused by bovine herpesvirus-1, contributes significantly to economic losses in the dairy and beef cattle industry. Lysin e has been shown reduce virulence of herpesviruses in felids and humans. Our objective was to evaluate the effects o f supplemental lysine on serum IBR antibody titer a nd rectal temperature in response to a modified-live Intranas al (IN) or Intramuscular (IM) respiratory-virus vac cination. Sixty-four neonatal Holstein bull calves (7±2 d of age; BW = 37±4.2 kg) were used in a completely randomized design. Calves were fed milk replacer supplemented with either 17 g/d L-lysine monohydrochloride (LYS; 28 calves) or an equivalent amount of casein (CAS; 28 calves) for 42 d. Calves were then vaccinated with either an IN IBR-Parainfluenza virus-3 (PI3) or an IM (IBR-PI3-bovine viral diarrhea type I and II, bovine respi ratory syncytial virus) modified-live vaccine on d 36. A c ontrol group (8 calves) received no supplement or v accination. All calves were housed in individual calf pens (1.2 ◊2.1 m). Daily feed intakes were monitored and BW measured weekly. Calves were bled on d 0, 35, 36, 37 and 42. Temperature data loggers were attached to rectal p robes and temperatures were recorded every 5 min from d 28 to d 42. No significant differences were determined f or average performance, rectal temperature, or IBR antibody titers with either IN or IM vaccinations betw een LYS and CAS treated calves (p>0.10). However, serum urea nitrogen and the ratio of serum lysine: Arginine increased (p<0.05) for LYS compared to CAS calves. These results suggest that supplementing lysine impacts nitro gen metabolism but does not alter the response to IBR v accination or animal performance in neonatal Holstein calves.

Management of acute streptococcal pharyngitis: still the subject of controversy.

Although most cases of acute pharyngitis are viral in origin, antibiotics are overused in its treatment. Streptococcus pyogenes (group A streptococcus, GAS), the principal bacterial pathogen of acute sore throat, is responsible for merely 5–30% of cases. Moreover, GAS pharyngitis is currently the only commonly occurring form of acute pharyngitis for which antibiotic therapy is definitely indicated. Therefore the differentiation between GAS pharyngitis and that of viral etiology is crucial. Accordingly, scientific societies as well as respected advisory bodies in Europe and North America, issued guidelines for the management of acute pharyngitis with the aim of minimizing unnecessary antibiotic prescriptions in its treatment. The aim of this review work is to confront the state of the art in acute GAS pharyngitis diagnosis and treatment with different approaches to its management represented by current European and North American guidelines. Although based on scientific evidence, international guidelines differ substantially in opinions whether GAS pharyngitis diagnosis should be based on microbiological testing, clinical algorithm or a combination of both. On the other hand, some European guidelines consider GAS pharyngitis to be a mild, self-limiting disease that does not require a specific diagnosis or antimicrobial treatment except in high-risk patients. There is an agreement among guidelines that if antibiotic therapy is indicated, phenoxymethyl penicillin should be the drug of choice to treat GAS pharyngitis.

Empirical validation of Polish guidelines for the management of acute streptococcal pharyngitis in children

ObjectiveGroup A Streptococcus (GAS) pharyngitis is currently the only commonly occurring form of acute pharyngitis for which antibiotic therapy is definitely indicated. Polish guidelines advocate the use of modified Centor score (MCS) to assess the probability of GAS pharyngitis. They advise performing throat culture or rapid antigen detection test (RADT) in children with score 2–3 in MCS and treating with antibiotic only those in whom GAS was detected. Negative RADT results should be confirmed by culture. In children with score 4, the guidelines allow to introduce empiric antibiotic therapy. Phenoxymethyl penicillin is recommended as a drug of choice to treat GAS pharyngitis. The aim of our study was to evaluate the accuracy of strategy recommended by Polish guidelines in identifying those children with acute pharyngitis who require antibiotic treatment. Hence, diagnostic values of score 4 in MCS and RADT were assessed using throat culture as a reference standard. Phenoxymethyl penicillin efficacy in GAS eradication and prevention of post-streptococcal complications were estimated as well. MethodsNinety children between 2 and 15 years of age with acute pharyngitis symptoms suggesting GAS etiology (MCS≥2), participated in our study. At the initial visit MCS was evaluated and two throat swabs were collected to perform RADT and culture. In children with GAS pharyngitis treated with penicillin, microbiological cure was assessed by performing two control throat cultures. Next, children were under observation for 3 months. ResultsPositive predictive value of score 4 in MCS turned out to be 48.05% (95% CI: 36.5–59.7%). RADT sensitivity, specificity and diagnostic accuracy proved to be 100%, 96%, and 98%, respectively. GAS eradication rate in children treated with penicillin turned out to be 92.5%. No post-streptococcal sequelae occurred in any child in 3-month observation. ConclusionsEmpiric antibiotic therapy in children with score 4 in MCS will result in significant overtreatment of those with nonstreptococcal pharyngitis. New generation RADT diagnostic value in GAS detection proved to be equivalent to that of culture, which obviates the need of backup culture in children with negative RADT results. Phenoxymethyl penicillin revealed high eradication efficacy and proved to prevent post-streptococcal sequelae in children with acute GAS pharyngitis.

A 14-Year Old Boy with Sore Throat and Syncope

Healio.com/Pediatrics | 403 Editor’s note: Each month, this department features a discussion of an unusual diagnosis. A description and images are presented, followed by the diagnosis and an explanation of how the diagnosis was determined. As always, your comments are welcome via email at Pediatrics@Healio.com. For diagnosis, see page 404 A14-year-old boy presented to the emergency department with a syncopal episode. The patient stated he was walking when he suddenly became flushed and diaphoretic. He experienced a witnessed loss of consciousness of 2 to 3 minutes without seizure-like activity or a post-ictal period. He had experienced a similar episode 2 years earlier when he had become dehydrated after being physically active for a prolonged period of time; he was told it was caused by heat exhaustion. The patient denied any history of alcohol or drug use, or family history of sudden cardiac death. On review of systems, the patient stated he had a sore throat for 2 days with intermittent chills, as well as decreased oral intake for 1 day. On examination, the patient’s vital signs included an oral temperature of 102.1°F, blood pressure of 124/69 mm Hg, heart rate of 122 beats per minute, respirations of 18 per minute, and room air oxygen saturation of 99%. The patient was a well-appearing adolescent male in no acute distress. His exam was significant for an exudative pharyngitis with anterior cervical lymphadenopathy, as well as a rapid regular heart rate with a prominent S2. An electrocardiogram (ECG) was performed upon arrival to the emergency department (see Figure 1). After receiving 500 mg ibuprofen, 500 mg penicillin VK for streptococcus pharyngitis, and a 500-mL normal saline bolus, the patient had a repeat ECG performed (see Figure 2, page 404). Six minutes later, he had a documented oral temperature of 99.2°F. The patient was transferred to a hospital with a pediatric cardiologist. The following morning, a repeat ECG was performed (see Figure 3, page 404), and an echocardiogram found no evidence of structural cardiac abnormalities. Case Challenge

The ab initio study and NBO interpretation of solvent effects on the structural stability and the chemical reactivity of penicillin-V conformations

Quantum mechanics (QM) methods were used to examine the electronic structure and the relative stability of penicillin-V (PV) conformations in the gas phase and the different solvent media. The effects of solvent dielectric constant and the computational methods were analyzed on the conformational stability of β-lactam-thiazolidine bicyclic system, its geometry and its reactivity. Our findings indicated that in the PV, the axial form of thiazolidine ring is more stable than equatorial form one in all of the tested media. This is in agreement with the NMR studies performed on PV that indicate the axial conformation is the dominant form in solid state. Furthermore, the atomic charges computations and natural bond orbital Interpretation (NBO) represented that by increasing the solvent dielectric constant, the charge values on the C5 and C7 atoms of the β-lactam ring decrease, while HOMO–LUMO gap and occupancy values of the contained bonds in β-lactam ring of the interested structures increase. Hence, the β-lactam ring possesses the lowest reactivity against nucleophilic attacks and the highest stability in presence of implicit waters. However, it can be concluded that the structural stability of penicillin-V conformations is controlled by solvent’s polarity and its dielectric constant, the electrophilic nature of β-lactam ring and HOMO–LUMO gap.

Prophylaxis for Leg Cellulitis

Leg cellulitis is common and often recurrent. Does continuous treatment with phenoxymethylpenicillin 250 mg twice daily prevent recurrence? To answer this question, investigators enrolled 274 subjects with recurrent cellulitis seen at 28 hospitals in the U.K. and Ireland into a 36-month, double-blind, randomized, placebo-controlled trial of this prophylactic low-dose penicillin. Eligible patients had had a recurrent episode of leg cellulitis within 24 weeks of the enrollment date and at least two …